DRC-2021-005540 - 0901a06880e6d461

Radioactive Material License Application / Federal Cell Facility

Page M-1 Appendix M April 9, 2021
Revision 0

APPENDIX M

GEOSYNTEC FEDERAL CELL ENGINEERING EVALUATION

(Geosyntec, 2021)

Federal Cell Engineering Evaluations April 2021

COMPUTATION COVER SHEET

Client:
Energy
Solutions Pro ect: Federal Cell at Clive Facilit Pro ect No.: SLC1025

Title of Computations GEOTECHNICAL ENGINEERING EVALUATIONS

Computations by: Signature 3/11/2021
Printed Name Madeline Downing Date
Title Senior Staff Enginee

Assumptions and
Procedures Checked
by:
(peer reviewer)
Signature 3/17/2021
Printed Name Bora Batura , PhD, G.E. Date
Title Principal

Computations
Checked by:
Signature 3/17 2021
Printed Name Bora Baturay, PhD, G.E. Date
Title Principal

Computations
backchecked by:
(originator)
Signature 3/18/2021
Printed Name Madeline Downing Date
Title Senior Staff Enginee

Approved by:
(pm or designate) Si nature 3/18/2021
Printed Name Keaton Botelho, P.E. Date
Title Senior Enginee

Approval notes:

Revisions (number and initial all revisions)

No. Sheet Date B Checked b Approval

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Client: ES Project: Federal Cell Project/ Proposal No.: SLC1025 Task No.: 01

GEOTECHNICAL ENGINEERING EVALUATIONS
FOR FEDERAL CELL AT THE CLIVE FACILITY
CLIVE, UTAH
Table of Contents
1. Objective ................................................................................................................................3 
2. Background ............................................................................................................................3 
3. Site Characterization ..............................................................................................................4 
3.1 Document Review ....................................................................................................4 
3.2 Subsurface Stratigraphy ...........................................................................................5 
3.3 Groundwater .............................................................................................................6 
3.4 Seismic Hazard Evaluation ......................................................................................7 
4. Slope Stability ........................................................................................................................7 
4.1 Federal Waste Cell Geometry ..................................................................................8 
4.2 Subsurface Material Properties ................................................................................9 
4.3 Federal Cell Cover and Base Liner System Material Properties ..............................9 
4.4 Federal Cell Waste Material Properties for Stability ...............................................10 
4.5 Analysis Methodology .............................................................................................11 
4.6 Design Criteria .........................................................................................................11 
4.7 Analyses Scenarios ...................................................................................................12 
4.8 Short-Term Stability .................................................................................................12 
4.9 Long-Term Stability Analysis ..................................................................................13 
4.10 Pseudostatic Stability ...............................................................................................14 
4.11 Post-Earthquake Stability .........................................................................................15 
4.12 Seismic Deformation ................................................................................................16 
5. Settlement Analysis ...............................................................................................................17 
5.1 Previous Analyses ....................................................................................................18 
5.2 Compressibility Properties of Foundation Soils .......................................................18 
5.3 Federal Cell Loading and Geometry ........................................................................20 
5.4 Elastic Settlement (Immediate) of the Sand-Like Units (1 & 3) ..............................21 
5.5 Primary Consolidation ..............................................................................................22 
5.6 Secondary Compression ...........................................................................................23 
5.7 Consequences of Settlement .....................................................................................24 
6. Liquefaction ...........................................................................................................................25 
6.1 Previous Analyses ....................................................................................................25 
6.2 Seismic Design Parameters ......................................................................................25 
6.3 Liquefaction of Sand-Like Soils ...............................................................................26 

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Client: ES Project: Federal Cell Project/ Proposal No.: SLC1025 Task No.: 01

6.4 Cyclic Softening of Clay-Like Soils ........................................................................26 
7. Conclusions ............................................................................................................................27 
7.1 Global Static, Seismic Slope Stability and Deformation .........................................27 
7.2 Settlement .................................................................................................................27 
7.3 Liquefaction and Cyclic Softening ...........................................................................28 
8. References ..............................................................................................................................29 

Attachments
Attachment A: Supporting Documents
Attachment B: Global Static and Seismic Slope Stability Results
Attachment C: Seismic Deformation Analysis
Attachment D: Settlement Analysis
Attachment E: Liquefaction Analysis

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Client: ES Project: Federal Cell Project/ Proposal No.: SLC1025 Task No.: 01

1. OBJECTIVE
The objective of this analysis is to evaluate the geotechnical engineering mechanisms related to
the performance of the proposed Federal Cell at the EnergySolutions, LLC (EnergySolutions)
Clive Facility in Clive, Utah. The geotechnical analyses performed for the Federal Cell include
static and seismic stability, foundational soil settlement, and liquefaction triggering for the
proposed embankment. The evaluations presented herein have been based on conservative
approaches to evaluate this facility and are designed to capture the potential long-term changes
over the design life. The analyses were performed in accordance with our proposal dated February
17, 2021.
2. BACKGROUND
Based on our understanding of the Federal Cell design, the intended waste to be placed in the
containment cell includes depleted uranium (DU) stored in cylinders and drums and controlled
low strength material (CLSM); a flowable fill which will be placed in between and around the
cylinders and drums. According to the Radioactive Waste Inventory for Clive DU PA Model v1.4
(Neptune, 2015), approximately 690,000 metric tons of the DU filled drums and cylinders are
intended to be placed in the proposed cell. Existing grades at the proposed cell location range
between 4,268 and 4,270 feet above mean sea level (amsl). The Design Drawings
(EnergySolutions, 2020) suggest the average subgrade elevation of the proposed cell is
approximately 4,261 feet amsl, which would be achieved by excavating approximately 7 to 9 feet
below ground surface (bgs).

To support the design of the proposed Federal Cell, EnergySolutions and Neptune and Company,
Inc. (Neptune) developed the Final Report for the Clive Depleted Uranium Performance
Assessment (DU PA) and the DU PA Model v1.4 in 2015 and submitted it to the Utah Division of
Waste Management and Radiation Control (DWMRC) for review. The DWMRC provided a
review of the DU PA and documented their feedback in their Technical Report dated January 28,
2021 (DWMRC, 2021). EnergySolutions requested that Geosyntec provide assistance to respond
to DWRMC’s feedback and demonstrate compliance with the performance objectives of the Utah
Administrative Code (UAC) R313-25-19 through 23 and 10 Code of Federal Regulations (CFR)
61.41 through 44, specifically the geotechnical stability evaluations. Geosyntec performed a
review of the referenced Technical Report and has subsequently completed the following
engineering evaluations to help address the technical issues identified by the DWMRC:

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Client: ES Project: Federal Cell Project/ Proposal No.: SLC1025 Task No.: 01

 Global static slope stability of the proposed Federal Cell: Short- and long-term stability
including analysis of the various groundwater elevation conditions (current and potential
groundwater level rise);
 Seismic slope stability of the proposed Federal Cell: Pseudostatic stability and deformation
analysis of the most critical stability section;
 Settlement of the proposed Federal Cell foundational soils: Immediate and long-term
settlement analysis including evaluation of embankment response to foundation settlement
over the design life; and
 Liquefaction: Liquefaction triggering analysis caused by potential rise in groundwater
elevation.

3. SITE CHARACTERIZATION
The subsurface conditions and proposed Federal Cell liner and cover system components were
characterized based on our review of existing explorations, previous parameterizations performed
for adjacent existing waste cells, and available data provided for our review. The following
sections summarize the documents reviewed, subsurface stratigraphy characterization,
groundwater conditions, and seismic design parameters used to perform our engineering
evaluations presented in this calculation package.
3.1 Document Review
Extensive subsurface explorations have taken place at the Clive Facility dating back to 1984 and
extending through 2020 (Figure 1 presents a site layout of the explorations used in this evaluation).
The following reports provided to us for review were utilized to characterize the subsurface
stratigraphy beneath the proposed Federal Cell, define the groundwater levels critical for the
engineering evaluations, and define the seismic hazard parameters at the facility:
 Hydrogeologic Report for the Clive Facility prepared by Bingham Environmental
(Bingham) dated 1992 (including Addendum 1 and 2);
 Combined Embankment Study for Class A Waste Embankment (CAW) (just North of the
proposed Federal Cell) prepared by AMEC Earth & Environmental (AMEC) dated
December 2005;
 Geotechnical Update Report for CAW prepared by AMEC dated February 2011;
 Seismic Hazard Evaluation/Seismic Stability Analysis Update for CAW prepared by
AMEC dated April 2012; and

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Client: ES Project: Federal Cell Project/ Proposal No.: SLC1025 Task No.: 01

 Phase 1 Basal Depth Aquifer Study for Clive Facility prepared by Stantec Consulting
Services, Inc. (Stantec) dated September 2020.
3.2 Subsurface Stratigraphy
Based on our review of the referenced Hydrogeologic Report (Bingham, 1992), three exploratory
drill holes were excavated beneath the proposed Federal Cell in 1991 by Overland Drilling under
the direction of Bingham personnel. Drill hole logs for GW-36 through GW-38 (Attachment A)
were reviewed to develop a generalized subsurface stratigraphy beneath the proposed Federal Cell
(Bingham, 1992). In general, the geologic units include the following from top to bottom:
 Unit 4 Silty Clay – silty clays, classifying as CL in accordance with Unified Soil
Classification System (USCS), containing some fine silt layers and is generally dry near
surface with increasing moisture with depth, and medium stiff to stiff consistency.
 Unit 3 Silty Sand – dense to medium dense silty sands and silts containing few thin clay
layers.
 Unit 2 Silty Clay – interbedded clay and silt layers with a few isolated sand layers up to 2-
feet thick, generally stiff, and saturated clays.
 Unit 1 Silty Sand with interbedded clay/silt lens – generally dense to very dense sands.

As mentioned previously, existing grades beneath the cell range between 4,268 to 4,270 feet above
mean sea level (amsl). The Design Drawings (EnergySolutions, 2020) suggests the average
subgrade elevation of the proposed cell is approximately 4,261 feet amsl. This will result in
excavations ranging between 7 to 9 feet into native Unit 4. Minimal portions of the Unit 4 will
therefore be left in the subgrade. We assume that soft spots of these silty clays will be reworked
and compacted prior to construction of the Federal Cell clay liner. Conservatively we have
assumed approximately 2 feet of Unit 4 silty clay with medium stiff consistency remains beneath
the Federal Cell for the engineering evaluations presented herein. For the purposes of this
calculation package, the subsurface geology and Federal Cell is idealized as shown in Figure 2
below.

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Client: ES Project: Federal Cell Project/ Proposal No.: SLC1025 Task No.: 01

Figure 2 Subsurface Stratigraphy

The subsurface conditions beneath the Federal Cell and CAW embankment are generally
consistent, with the exception of Unit 2 extending on average only 45 feet bgs as opposed to the
approximated 64 feet bgs for the CAW. Conditions documented from various explorations are in
general agreement with the hydrogeologic cross sections across the Clive Facility (Attachment A).
The same geologic unit numbers used in the hydrogeologic characterization (Bingham, 1992) are
used herein for consistency. The importance of this finding is the subsurface conditions are
sufficiently uniform and therefore a single idealized profile is appropriate for the Federal Cell.
3.3 Groundwater
The latest static groundwater levels were collected during the referenced Aquifer Study (Stantec,
2020). Depth to water in wells I-1-30, I-1-50, I-1-100, and I-1-700 ranged between 28 to 31 feet.
Groundwater depth reported on well logs GW-36 through GW-38 (used for subsurface stratigraphy

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Client: ES Project: Federal Cell Project/ Proposal No.: SLC1025 Task No.: 01

characterization beneath the Federal Cell) was encountered at approximately 20 feet bgs.
Groundwater records for these wells report a depth of approximately 20 feet between 2016 and
2020. A depth of 20 feet was therefore used to represent the existing conditions in our stability and
settlement analyses.
Based on available historical records, no significant groundwater elevation rises have occurred at
the Facility. However, DWMRC has requested that the proposed Federal Cell be evaluated for
potential geotechnical instabilities over the design life caused by future hypothetical groundwater
rise events. Therefore, we also evaluated a design groundwater level elevation synonymous with
the ground surface elevation as a bounding scenario as requested by DWMRC. The extreme-case
groundwater rise condition was used to evaluate liquefaction triggering and long-term stability of
the proposed Federal Cell.
3.4 Seismic Hazard Evaluation
DMWRC accepted an updated assessment of the seismic hazard for the Clive Facility consistent
with the requirements of the Utah Code of Regulations R313-25-8(5) to justify a 2012 licensing
action (AMEC, 2012). The previously accepted seismic hazard analysis for the site was therefore
used in this analysis. The seismic hazard assessment was based on deterministic assessment of the
84th percentile peak ground acceleration (PGA) associated with the Maximum Credible
Earthquake (MCE) for known active and potentially active faults in the site region and the PGA
obtained from a probabilistic seismic hazard analysis (PSHA) considering a 5,000 year return
period to assess the seismic hazard for earthquakes that may occur on unknown faults in the area
surrounding the site. The largest PGA from the assessment was 0.24g which was same for both
deterministic and probabilistic methods. The maximum magnitude (Mw) identified was 7.3. Based
on our review of the seismicmap.org tool created by Structural Engineers Association of California
(SEAOC) and California’s Office of Statewide Health Planning and Development (OSHPD) and
a review of Unified Hazard Tool (UHT) by the US Geologic Survey (USGS), the PGA obtained
using current fault and ground motion estimation models is 0.22g. Therefore, the seismic
parameters previously accepted by DMWRC are considered reasonable estimates of the seismic
hazard for the site and were utilized in Geosyntec’s seismic hazard analyses documented in this
package.
4. SLOPE STABILITY
The evaluation of global slope stability of the Federal Cell waste embankment was identified as
an unresolved requirement in the referenced Technical Report (DWMRC, 2021). Analyses
presented herein for global stability consider the geotechnical response of the site for the 10,000-

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Client: ES Project: Federal Cell Project/ Proposal No.: SLC1025 Task No.: 01

year design life (or compliance period). Deep-seated global slope stability analyses were
performed for both static and seismic conditions. In addition, the stability analyses include
groundwater modeling at current conditions and at the existing ground surface that represents
extreme-case bounding future scenario in terms of pore pressures for stability. The following
sections summarize the methods and analyses performed to demonstrate global static and seismic
stability of the proposed Federal Cell. The graphical output files for the analyses are presented in
Attachment B.
4.1 Federal Waste Cell Geometry
Based on our review of the Design Drawings for the Federal Cell dated February 2021
(EnergySolutions, 2021), the proposed cell will retain the waste previously described in Section 2
with maximum side slopes of 20 percent (%). For slope stability analyses, the cell geometry has
been summarized in Table 1 below.
Table 1: Summary of Federal Cell Design Dimensions
Description Dimension and Unit
Length 1,920 feet
Width 1,225 feet
Height 52 ½ feet, maximum at crest
Base Elevation 4,262 to 4,263 feet
Crest Elevation 4,314.5 feet
Shoulder Side Slopes 20%
Shoulder Side Slope Width 175 feet
Shoulder Side Slope Height 32.5 feet
Cover Top Gradient 2.4%

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Client: ES Project: Federal Cell Project/ Proposal No.: SLC1025 Task No.: 01

4.2 Subsurface Material Properties
The material properties of the subsurface soils used to evaluate slope stability reflect our review
of available geotechnical lab data, boring logs, and previous parameterization of the adjacent CAW
performed and compiled for DWMRC’s 2012 Class A West licensing decision (2005 & 2011).
The subsurface units are generally consistent beneath the CAW and the proposed Federal Cell,
therefore, Geosyntec considers previous material property assignment of the units to be generally
applicable for the analyses presented herein. Based on review of the geotechnical lab data
summarized in 2005 and the DWMRC’s 2012 licensing action, and the boring logs available within
the Federal Cell footprint, Geosyntec made more conservative assumptions for the undrained shear
strength of clay units. The undrained shear strengths test results reflect the in-situ conditions during
the previous explorations. These selections are considered potentially conservative as
consolidation of the underlying clay units are expected to occur during construction of the cell,
resulting in strength gain overtime with pore pressure dissipation. The material properties for use
in slope stability analyses are summarized in Table 2 below.
Table 2: Summary of Subsurface Material Properties for Slope Stability
Unit Material
Classification
Depth
Total Unit
Weight,

Undrained Drained
Undrained
Shear
Strength,
Su
Friction
Angle, '
Effective
Cohesion, c'
(f -s) (pcf) (psf) (de ) (psf)
4 CL/ML 0 - 9 118 1,000 29 0
3 SM 9 - 23 120 - 34 0
2 CL-ML 23 - 45 121 1,500 29 1,000
1
SM with
Interbedded thin
lifts of CL-ML
45 - 100 120 - 29 0

4.3 Federal Cell Cover and Base Liner System Material Properties
The material properties for the cover and base liner system components of the Federal Cell were
selected based on review of embankment cell designs, gradations and specifications presented on
the design drawings, a review of estimated properties from literature, and our previous experience
with similar type materials. The material properties for the liner and cover system components for
use in slope stability analyses are presented in Table 3 below.

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Client: ES Project: Federal Cell Project/ Proposal No.: SLC1025 Task No.: 01

Table 3: Summary of Liner and Cover System Material Properties for Slope Stability
System
Component
Material
Classification
Thickness

Total Unit
Weight,


Friction
Angle, '

Apparent
Cohesion, c'
Undrained
Shear
Strength
(inches) (pcf) (de ) (psf) (psf)
Side Rock Rip Rap 18 135 40 - -
Top Slope
Cover
Silty Clay from
Native Unit 4
amended with 15%
ravel
12 120 30 200
-
Filter Zone
Mix of
Gravel/Sand/Fines
(GM-GC)
12 130 34 0
-
Frost
Protection
Cobble/Gravel/Soil
Mixture (GM-GC) 18 130 38 0 -
Radon Clay 24 123 0 1,000 -
Evaporative
Zone
Silty Clay from
Native Unit 4 12 120 29 300 -
Clay Liner Clay 24 123 28 0 1,0001
Liner
Protective
Cove
Silty Sand 12 118 38 250 -
Notes:
1. Undrained strength properties assigned to Clay Liner only. All other materials expected to exhibit drained
strength under the analyzed loading conditions.
4.4 Federal Cell Waste Material Properties for Stability
The Federal Cell waste fill material properties for stability are based on our understanding of the
planned waste placement methods and a review of readily available literature on the shear strength
of CLSM. The stability analyses presented herein assume that the proposed Federal Cell will be
filled with DU in the form of LLRW cylinders and drums surrounded by flowable fill (CLSM) at
a ratio of approximately 1.9 CY of CLSM per CY of DU placed below grade and beneath the
embankment top slope. While the compressive strength is typically used to define specifications
for CLSM (150 psi specified for the neighboring LARW embankment), a long-term degraded
condition over the 10,000-year compliance period is better represented by the residual shear
strength resulting from shear zone failures between the waste cylinders and drums and solidified
CLSM. Alternative characterizations for the waste were considered, however the residual strength

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approach is considered to be an appropriate representation. According to a study titled “Flowable
Backfill Materials from Bottom Ash for Underground Pipeline,” UU triaxial testing of CLSM
suggests that residual strength of CLSM may exhibit strength properties of 36 to 46 degrees for
effective friction angle and an effective cohesion of 49 to 140 kPa (Lee and Kim, 2014).
Conservatively, the Federal Cell waste for stability was assigned a friction angle of 30 degrees
and unit weight of 120 pcf (consistent with unit weight selected for the LARW) with no effective
cohesion. This characterization is conservative and represent the potential long-term degradation
of the CLSM and DU fill over the compliance period.
4.5 Analysis Methodology
Slope stability analyses for Federal Cell was performed using the two-dimensional computer
program SLOPE/W version 10.2.0.19483 (GEOSTUDIO, 2019). GEOSTUDIO programs are a
widely used for geotechnical and geo-environmental modeling and has been in employed by
industry geotechnical engineers since 1977 and used in over 100 countries. SLOPE/W is the
leading slope stability software for soil and rock slopes. GEOSTUDIO, maker of SLOPE/W,
reports that several US Federal clients using their software include USACE, Federal Energy
Regulatory Commission (FERC), United States Department of Agriculture Natural Resources
Conservation Service (USDA NRCS), Federal Bureau of Reclamation, and Environmental
Protection Agency (EPA). The SLOPE/W program can effectively analyze a variety of slope
surface shapes, pore-water pressure conditions, soil properties, and loading conditions. The
selected SLOPE/W analyses were based on the Morgenstern-Price method of slices, which
satisfies both moment and force equilibrium stability on circular sliding surfaces. The method of
slices analysis is consistent with guidelines presented by the US Army Corps of Engineers
(USACE) Engineering and Design Slope Stability Engineering Manual No. 1110-2-1902
(USACE, 2003). The results of the slope stability analyses are typically presented in terms of a
factor of safety (FS) defined as the ratio of the total stabilizing forces/moments along an assumed
sliding plane divided by the total sum of internal and external driving forces/moments acting on
the sliding mass. SLOPE/W stability analysis graphical results include the assumed critical sliding
surface and corresponding rotation center and resulting sliding mass divided into slices for
computational purposes, and material properties.
4.6 Design Criteria
The design criteria for global static and seismic slope stability evaluations presented herein were
adopted from the DWMRC’s CAW licensing action. The accepted criteria are commonly used for
evaluating embankment and dam stability and are consistent with Geosyntec’s experience with
similar projects. The criteria and associated literature references are summarized in Table 4 below.

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Table 4: Geotechnical Design Criteria Summary
Analysis Criteria Reference
Static Stability FS>1.5 USACE (2003)
Seismic Stability
Seismic coefficient (kh) = ½ PGA Hynes-Griffin & USACE (1984)
Pseudostatic, FS > 1.2 Hynes-Griffin & USACE (1984)1
Pseudostatic FS = 1, Post-
earthquake cover deformations
150 300 mm allowable
Makdisi & Seed (1978)
1. FS of 1.2 was conservatively adapted in previous analyses in 2011 accepted by DWMRC for CAW licensing
action based on a review of Hynes-Griffin & USACE (1984).
4.7 Analyses Scenarios
The following conditions were analyzed to evaluate global static slope stability of the Federal Cell.
Upon review of the North-South and East-West geometries and adjacent features of the Federal
Cell and existing groundwater levels, two cross-sections were found to be representative of the
cell embankment for stability analyses: one section adjacent the proposed ditch and inspection
road and one section adjacent an existing waste cell [11(e) or CAW] as shown on the referenced
drawings (EnergySolutions, 2020):
 Short-term with existing groundwater, undrained strength of clay-like soils.
 Long-term with existing groundwater, drained strength.
 Long-term with groundwater rise, drained strength.
4.8 Short-Term Stability
Short-term loading conditions represent temporary construction conditions where pore water
pressures generated by the loads associated with waste embankment construction have not
dissipated in the clay-like soils and soil behavior can be characterized as undrained.
The various modes of failure (i.e., circular failures, block failures, deep-seated, and shallow)
commonly seen in embankments of similar design and geology were evaluated to identify the
critical case for each scenario analyzed. The most critical failure surface is herein reported for each
section and loading condition. The results of short-term stability analyses are presented in terms
of FS as presented in Attachment B and summarized in Table below. The FS for both sections

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exceed the design criteria of 1.5 for static conditions. The proposed cell geometry is therefore
considered stable under short-term conditions.
Table 5: Federal Cell Slope Stability Results for Short-Term Conditions
Section Groundwater
Factor
of
Safety
Critical Failure
Mode
Minimum
Required
Factor of Safety
Figure
Adjacent Road/Ditch
Existing
Conditions at 20
feet s
2.7
Block Failure
Through Undrained
Unit 2 ative
1.5 B-1
Adjacent Cell 11(e)
Existing
Conditions at 20
feet b s
2.6
Block Failure
Through Undrained
Unit 2 Native
1.5 B-2

4.9 Long-Term Stability Analysis
Long-term slope stability was evaluated considering the two design groundwater levels, existing
conditions (20 feet bgs) and the extreme-case groundwater rise conditions (base elevation), and
drained soil material properties. The drained shear strength of the foundation soils, liner, and cover
materials were selected for a Mohr-Coulomb SLOPE/W material model. Materials are expected to
exhibit drained strength properties in the long-term condition where pore pressures have dissipated
over time, following construction completion of the cell.
The various modes of failure (i.e., circular failures, block failures, deep-seated, and shallow)
commonly seen in embankments of similar design and geology were evaluated to identify the
critical case for each scenario analyzed. The most critical failure surface is herein reported for each
section and loading condition. The results of the long-term stability analysis are presented in terms
of FS summarized in Table below and presented in Attachment B. The FS for all scenarios
analyzed exceed the recommended value. Therefore, the proposed Federal Cell design is
considered stable under long-term conditions.

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Table 6: Federal Cell Slope Stability Results for Long -Term Conditions
Section Groundwater Factor of
Safety
Critical Failure
Mode
Minimum
Required
Factor of
Safety
Figure
Adjacent
Road/Ditch
Groundwater Level at Existing 20
feet bgs 3.4 Block Failure
Through Clay Liner 1.5 B-3
Groundwater Level during Future
Rise Event (modeled at base
elevation)
3.4
Block Failure
Through Unit 4
ative
1.5 B-4
Adjacent Cell
11(e)

Groundwater Level at Existing 20
feet bgs 3.3 Block Failure
Through Clay Liner 1.5 B-5
Groundwater Level during Future
Rise Event (modeled at base
elevation)
3.3
Block Failure
Through Unit 4
ative
1.5 B-6

4.10 Pseudostatic Stability
Pseudostatic slope stability procedures are commonly used to evaluate the likely seismic
performance of embankment and dam slopes. The pseudostatic analysis presented in this section
is based on the previously accepted analyses by DWMRC and guidelines presented in the Hynes-
Griffin and Franklin method (Hynes-Griffin, 1984). In pseudostatic analyses, the effects of an
earthquake are evaluated by applying a static horizontal inertial force to the potential sliding mass.
This horizontal inertial force is expressed as the product of the seismic coefficient (k) and the
weight of the potential sliding mass. If resulting forces including the inertial forces are greater than
the resisting forces, then seismic deformations will take place. In accordance with the design
criteria adopted from adjacent cell designs based on Hynes-Griffin and Franklin method (Hynes-
Griffin, 1984), a seismic coefficient equal to 50% of the PGA was used for the pseudostatic
analysis and a FS of 1.2 was adapted as a limiting factor of safety for large deformations. The
analysis also used groundwater conditions that represent the extreme-case groundwater rise event
and undrained material properties for the clay liner and foundational units..
Various modes of failure are evaluated to identify the critical case for each scenario analyzed. The
most critical failure surface has been reported herein for each section and loading condition. The
results of the pseudostatic stability analysis are presented in terms of FS summarized in Table
below and presented in Attachment B. The FS for the scenarios analyzed meet the design criteria.
Therefore, the proposed Federal Cell design is not expected to experience large deformations

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during seismic loading. Simplified seismic deformation analyses for the range of anticipated
deformations are presented in Section 4.1.2.
Table 7: Federal Cell Slope Stability Results for Pseudostatic
Section Loading Condition Factor
of Safety
Critical Failure
Mode
Minimum
Required
Factor of
Safety
Figure
Adjacent
Road/Ditch
k = 0.12 g
Groundwater Level during
Future Rise Event (modeled at
base elevation)
1.3 Block failure through
Unit 4 Native
1.2

B-7

Adjacent
Cell 11(e)

k = 0.12 g
Groundwater Level during
Future Rise Event (modeled at
base elevation)
1.3 Block failure through
Unit 4 Native
1.2

B-8

4.11 Post-Earthquake Stability
To demonstrate the potential effects of cyclic softening in native soils discussed further in Section
6, the proposed Federal Cell was analyzed in SLOPE/W with the potential strength degradation of
the clay-like soils following an earthquake event. To model this in SLOPE/W, the foundational
clay-like soils (Units 2 and 4) and clay liner were modeled with reduced undrained strength
properties. An undrained shear strength degradation of 50% was used to model this phenomenon.
This strength reduction is a lower bound estimate to the strength reduction, if any cyclic softening
were to happen. Justification for this conservative assumption is provided in Section 6. A
minimum FS for stable static conditions of 1.5 was considered acceptable per design criteria
and criteria found in published literature summarized in Section 4.6 above.
Various modes of failure (i.e. failures through deeper clay Unit 2, clay liner, and shallower clay
Unit 4) are evaluated to identify the critical case for each section analyzed. The most critical failure
surface has been reported here for each section and loading condition. The results of the post-
earthquake stability analysis are presented in terms of FS summarized in the Table below and
presented in Attachment B. The minimum FS of 1.5 was achieved for the sections analyzed and
is therefore considered stable in a post-earthquake scenario where clay-like soils have undergone
significant shear strength degradation. A discussion on cyclic softening of clay-like soils is
provided in Section 6 of this package.

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Table 8: Federal Cell Slope Stability Results for Post-Earthquake Cyclic Softening
Section Loading Condition Factor
of Safety
Critical Failure
Mode
Minimum
Required
Factor of
Safety
Figure
Adjacent
Road/Ditch
Groundwater Level during
Future Rise Event (modeled at
base elevation)
1.8
Block Failure
Through Unit 4
Native
1.5

B-9

Adjacent
Cell 11(e)

Groundwater Level during
Future Rise Event (modeled at
base elevation)
1.6
Block Failure
Through Unit 4
Native
1.5

B-10

4.12 Seismic Deformation
The seismic deformation analysis for the Federal Cell was performed using the Makdisi and Seed
(1978) simplified method for estimating seismically induced deformations for earthen
embankments and geosynthetics. The site-specific seismic design parameters such as PGA and
Mw required for estimating seismically induced slope deformations were based on the referenced
seismic hazard analysis that justified DWMRC’s 2012 license action and as discussed in Section
3.4, are as follows:
 PGA = 0.24g
 Mw = 7.3
The seismic deformation analysis includes performing a pseudostatic stability analysis and
determining the yield coefficient, ky, resulting in an FS equal to 1. The ky is next compared with
the maximum estimated inertial force, kmax, to empirically estimate the anticipated embankment
deformations based on the earthquake magnitude. In accordance with the current state of practice
and previous analyses for the adjacent cells, seismically induced deformations of 150 to 300 mm
are considered acceptable. The seismic deformation analysis results are summarized in Table 9
and presented in Attachment C.

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Table 9: Federal Cell Seismic Deformation Results
Case/Description ky ümax y
(ft)
H
(ft) y/H kmax/ümax kmax ky/kmax
Estimated
Deformation
(mm)
Critical Section Failure
Through Unit 4 Native, Entire
Slope Face (y/H=1), Adjacent
Cell 11(e)
0.18 0.58 52 52 1 0.34 0.2 0.91 4
Notes:
1. y is depth of sliding mass under evaluations
2. H is average height of the potential sliding mass

Results of the permanent deformation analyses (using undrained strengths and groundwater
rise elevation), estimate seismically induced deformations to be negligible. Therefore, the
performance of the Federal Cell under the provided earthquake ground motions, is considered to
be acceptable in terms of seismically induced deformations.

5. SETTLEMENT ANALYSIS
The DWMRC raised concerns for the uncertainty in the parameters used for geotechnical analysis
of the proposed Federal Cell foundation settlement and subsequent embankment response in the
referenced Technical Report (DWMRC, 2021). The following sections describe the method of
analysis and results of estimated elastic, primary consolidation, and secondary compression
settlement of the Federal Cell foundational soils and the consequences of these estimates.
Settlement calculations presented herein are considered conservative as the condition modeled
assumes a “wished into place” scenario. In reality, construction of the proposed cell is likely to be
slow enough (on the order of ±10 years) to allow for dissipation of pore pressures in the underlying
fine-grained soils, resulting in near completion of primary consolidation settlement by the end of
waste placement and start of cover construction. Conservatively we assumed primary
consolidation settlements would go on another year following final placement of waste. This is
considered conservative due to the presence of consistent interbedded sandy layers observed in the
subsurface. Sandy soils act as drainage layers that allow for pore pressures to dissipate and expedite
consolidation of the fine-grained soils. Over the course of construction, these fine-grained soils are
expected to experience this consolidation and be nearly complete by end of waste placement. This
phenomenon has been modeled and predicted for the other adjacent cells (AMEC, 2005). Based
on the analysis, Geosyntec’s opinion is that predicted settlement of the cell would not have an
adverse impact on the stable slope conditions as magnitude of settlement is expected be limited

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and would cause only limited flattening of the top slopes. The flattening slopes and potential
differential settlements could reduce the drainage slopes over the cover locally and affect
infiltration. This is something that should be considered during design and construction.
5.1 Previous Analyses
While other adjacent cells varied in geometry and waste fill types, findings of previous settlement
analyses and models for other cells were reviewed for comparison and consistency. The load and
geometry may vary, but the subsurface conditions beneath the adjacent cells are generally
consistent with that of the Federal Cell. Settlements of the foundational soils due to embankment
loading are projected to be on the order of 12 to 16-inches with secondary settlements calculated
over 500-year compliance period on the order of 8-inches. The analysis justifying DWMRC’s
license action for the CAW predicted and modeled these settlements for an embankment height of
approximately 100 feet for various waste types including compressible debris, incompressible
debris, and CLSM. The proposed waste and cover materials for the Federal Cell may have a greater
average unit weight than the CAW (120 pcf versus 100 pcf), but the proposed embankment is
almost half the height of the CAW. Therefore, Geosyntec predicts that the expected foundation
settlement for the Federal Cell will likely be less than the CAW models.
5.2 Compressibility Properties of Foundation Soils
The compressibility properties of the subsurface soils used to evaluate the foundation settlement
were estimated from laboratory testing results for the fine-grained soils and derived from typical
values for the coarse-grained soils at specified in-situ confining pressures. Correlations from
published literature were also used to supplement the laboratory data.
2005 interpretation of various explorations across the Clive Facility (D&M 1984, Bingham 1992,
AGRA 1999, and AMEC 2004) has been provided in Attachment A. In these previous studies,
consolidation tests were performed on fine-grained soil units (Units 2 and 4) that have been
consistently encountered in the subsurface across the Clive Facility. Geosyntec used the interpreted
results provided to evaluate consolidation properties (Cc, Cr, OCR) of these soils that also underlie
the proposed Federal Cell.

Initial void ratios (eo) from the consolidation tests were not provided in the aforementioned lab
summary data table (Attachment A), therefore Geosyntec used in-situ water content (w) laboratory
test results for the underlying soils to estimate the initial void ratio of the fine-grained soils through
the use of published empirical correlations. The eo of the materials was estimated using the
following relationship between water content and the specific gravity for saturated soils:

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𝑒 𝐺𝑠 𝑤/100
Where Gs is the specific gravity of the soils; assumed to equal 2.65.
The modified secondary compression index (Cαε) is typically calculated through interpretation of
the consolidation test results and defined as the slope of the compressive strain plotted against
logarithm of time observed post primary consolidation during the test. A correlation was used that
relates Cαε to the estimated in-situ moisture content. Cαε of the materials was estimated using the
following relationship between water content:

Cαε 0.0001𝑤
Elastic settlement of the coarse-grained materials (Units 1 and 3) are typically estimated through
use of the constrained modulus (Ms) of the soil. The sandy subsurface materials in Unit 3 are
assumed to have an elastic modulus of approximately 1,800 psi and a Poisson’s ratio of 0.25. The
subsurface materials in the Lower Sand Unit 1 are assumed to have an elastic modulus of
approximately 2,300 psi and a Poisson’s ratio of 0.38. The elastic modulus and Poisson’s ratios
were selected based properties of similar soils types are equivalent confining pressures (Qian et al.
2002). The Ms was calculated with equation presented above.
𝑀 𝐸 1 𝑣
1 𝑣1 2 𝑣
where:
vs = Poisson’s ratio of soil, ft; and
Es = elastic modulus of soil, lb/ft2.

The unit weights of geologic units are consistent with the assignments used in the slope stability
analyses discussed earlier.
A summary of the resulting settlement material properties used in our settlement analysis is
provided in Table 10.

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Table 10: Summary of Properties for Foundation Settlement Analysis
Unit
Thick
ness
Unit
Weight
γ
Constrained
Modulus
Ms
Primary
Compression
Index
Cc
Recompression
Index
Cr
Modified
Secondary
Compression
Index
Cαε
OCR Water
content
(%)
Initial
Void
Ratio
eo
(ft) (pcf) (psf) (psf)
4 2 118 - 0.25 0.02 0.004 5 40 1.06
3 14 120 311,040 - - - - - -
2 22 121 - 0.20 0.025 0.0045 1.5 45 1.2
1 55 120 531,560 - - - - - -

5.3 Federal Cell Loading and Geometry
For this calculation package, the settlement evaluation is based on the geometry presented in Table
1. For simplification the load was calculated as the maximum height (52.5 feet) of fill with an
average unit weight of 120 pcf. The loading shape was approximated with a rectangular loading
shape for the purposes of settlement analysis. This is considered representative of the average unit
weight of CLSM, the waste, and the various cover and liner materials. This results in a load over
the foundational soils of approximately 6,300 psf applied at the base of the Federal Cell.
A stress distribution model was developed to assess elastic and consolidation settlement. The
change in stress () is due to the Federal Cell height above the ground surface approximated to
be 6,300 psf. The change in stress in the underlying soils is calculated as the difference between
the existing overburden stress and the overburden pressure due to the Federal Cell. The distribution
of the total stress with depth assumes that the Federal Cell is an infinite embankment. The increase
in stress at depth ((z)) is equal to the change in stress at the surface () distributed over an
effective base area that increases with each depth interval below the surface, this is determined
with the following equations:
(z) = ( * Areabase)/Areaeffective
Areaeffective = (B +z)*(L+z) and
B = Base width of the cell (ft)

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L = Base length of the cell (ft)
z = interval depth below ground surface (ft)
The change in stress within the geologic units was evaluated for each 1-foot interval bgs. The stress
distribution calculations are presented in the settlement analysis calculations presented in
Attachment D.
The magnitude of loading estimated here are the average loading beneath the top deck portion of
the embankment where the maximum embankment height is experienced and expected to decrease
linearly over the top slopes to essentially to no loading at the toe of the embankment.
5.4 Elastic Settlement (Immediate) of the Sand-Like Units (1 and 3)
Because of the coarse-grained nature of sand-like units (Units 1 and 3), the settlement of these
layers is anticipated to be primarily the result of elastic or immediate settlement. To evaluate the
potential effects of elastic settlement of the sand units, the units are assumed to behave as an elastic
and homogeneous medium. The foundation settlement is calculated using the Elastic Settlement
Equation, which is:

𝑍∆𝜎
𝑀 𝐻
where:
Ze = elastic settlement of soil layer, ft;
Ho = initial thickness of soil layer, ft;
Δchange in stress, psf (discussed in Section 5.3); and
Ms = constrained modulus of soil, lb/ft2 (provided in Table 9, discussed in Section 5.3).

The change in stress at each 1-foot interval in Units 1 and 3 and the corresponding constrained
modulus were then used to calculate the elastic settlement with the equation presented above for
each layer interval. The results of each interval where then summated to a cumulative estimate for
elastic settlement of Units 1 and 3. The elastic settlement for each unit is summarized in the Table
below and presented in Attachment D. The elastic settlements are expected to occur during
construction of the Federal Cell and be complete prior to cover construction. The elastic settlement
reported herein is therefore not expected to adversely impact the long-term stability of the cover
and will likely not need to be considered or accounted for during cover construction.

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Table 11: Foundation Soil Elastic Settlement
Unit Material Description Estimated Elastic
Settlement (inches)
3 Upper Silty Sand 3
1 Deeper Silty Sand with CL/ML
lens 8

5.5 Primary Consolidation
Because of the fine-grained nature of Units 2 & 4, the settlement of these layers is anticipated to
be a result of consolidation. The subsurface stratigraphy is discussed in Section 3.2 above with
the material properties summarized in Table 10. To calculate the consolidation settlement (Sc),
Units 2 and 4 were broken into 1-foot thick intervals. The total consolidation settlement within
each unit was the summation of the consolidation settlement in the individual 1-foot thick layers.
Based on the consolidation lab data discussed in Section 5.2, the soils are likely overconsolidated.
The overconsolidation ratio (OCR) for Units 2 and 4 are presented in Table 10. The equation for
consolidation settlement for overconsolidated soil is as follows:

𝑆𝐶
1 𝑒 𝐻 𝑙𝑜𝑔𝜎′
𝜎′ 𝐶
1 𝑒 𝐻 𝑙𝑜𝑔𝜎′ 𝛥𝜎
𝜎′

where,
eo = See Table 10 initial void ratio
H = 1 thickness of the compressible layer interval (ft)
Cc = See Table 10 compression index
Cr = See Table 10 recompression index
OCR = See Table 10 overconsolidation ratio
’p = OCR *’vo maximum past pressure (psf)
’vo = varies initial vertical effective stress (psf). Groundwater was assumed at a
depth of 25 feet below the ground surface (existing level)

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 = varies change in stress due to overburden loading (psf) (See Section 5.3
for discussion and Attachment C for stress distribution
calculations)
Calculation of primary consolidation settlement of Units 2 and 4 is provided in Attachment D and
summarized in Table 12 below.
5.6 Secondary Compression
Secondary compression is typically observed after primary settlement is substantially complete.
For the purpose of calculations, this is often assumed as the time at which the material reaches
95% degree of consolidation. As discussed earlier, because the waste embankment placement takes
place relatively slowly, the primary consolidation is expected to be substantially complete as the
filling is complete and by the time cover materials are placed. With this assumption and using the
secondary compression parameter presented in Table 10, secondary compression during the
compliance period of 10,000 years was estimated through the following relationship:

𝑆𝑠 Cαε ∗ 𝐻100
𝑡2
𝑡1

Where
Ss time dependent secondary settlement occurring between t1 and t2
Cαε = See Table 9 modified secondary compression index
H100 = varies total thickness of compressible layers at the end of primary
consolidation (for each 1-foot interval in Units 2 and 4)
t1 = 1-year time between the placement of last significant waste in the cell and
cover construction (assumed to be 1 year based on review of
previous analyses and conservative assumptions regarding the pace
of construction)
t2 = 10,000 years time for which secondary settlements are estimated for (compliance
period of 10,000 years)

Summation of the secondary compression of each 1-foot interval of Units 2 and 4 was performed
to estimate the cumulative secondary compression of each unit. The calculations for secondary
compression are presented in Attachment D and summarized in Table 12 below.

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Table 12: Foundation Soil Consolidation and Secondary Compression Settlement
Unit Material Description
Estimated Primary
Consolidation
Settlement (inches)
Estimated Secondary
Compression
Settlement (inches)
4 Upper CL-ML 3 <1
2 Deeper CL-ML 9 5

5.7 Consequences of Settlement
Based on our understanding of the subsurface stratigraphy beneath the proposed Federal Cell and
review of other adjacent cell studies (AMEC, 2005 & 2011), there are two principal geologic units
(Units 2 and 4) which may be subject to long-term settlements. These long-term settlements
estimated in this calculation package are principally a result of consolidation settlements of fine-
grained soils. The upper sand unit (Unit 3) and lowermost sequence of sands with thin lifts of
clays and silts (Unit 1) are not anticipated to impact long-term settlements. The elastic
settlements of those layers were reported in this package to provide a complete picture of the total
estimated settlement in the foundational soils of the proposed Federal Cell. It is the primary
consolidation and secondary compression settlements, however, that should be considered during
design and construction of the cell cover. Based on the results presented in Table 12, 12 inches
of primary consolidation settlement and 6 inches of secondary compression settlement may
result from construction of the Federal Cell. Considering the loading rate, the primary
consolidation settlement will likely occur simultaneously during waste placement and will be
substantially complete by the time the waste reaches its final elevation. We assumed 1 year after
completion of waste placement for completion of primary consolidation, as a conservative estimate
discussed previously. Secondary compression settlements which are relatively small in magnitude,
however, should be considered in cover design to ensure proper drainage is achieved because these
settlements will occur after the cover construction. The analyses assumed a secondary compression
time period of 10,000 years per compliance period requirements. A conservative assumption of
zero secondary compression at the edge of the cell and the maximum magnitude of 6 inches
at the center would result in an average settlement gradient of 6 inches over approximately
600 feet as 0.1 %. Therefore, the current design gradient of 2.4% maybe reduced to 2.3% in an
average sense which is considered negligible.
The magnitude of settlements estimated here are for the top deck portion of the embankment where
the maximum embankment height is experienced and expected to decrease linearly over the top

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slopes to essentially no settlement at the toe of the embankment. Therefore, settlement of the
foundational soils as a result of construction of the Federal Cell are not expected to adversely
impact the adjacent cells.
Settlement plate instrumentation may be used during cell construction to monitor consolidation
settlements, project substantial completion of consolidation settlements, and confirm design
assumptions prior to construction of the cover. These results may be useful for future waste cell
designs and construction. Overbuilding the cover and performing inspections and routine
maintenance over the monitoring period may help to mitigate the effects of long-term settlement.
6. LIQUEFACTION
Based on our understanding of the Technical Report (DWMRC, 2021), we understand the 10,000-
year compliance period for the proposed Federal Cell presents a need for conservative approaches
to analyzing the geotechnical stability mechanisms. The following sections summarize the
liquefaction analyses performed for the proposed Federal Cell that support this need. The analyses
presented are based on an extreme groundwater level rise resulting in a groundwater elevation
equal to the current existing ground surface (a 25 feet groundwater rise event).
6.1 Previous Analyses
A groundwater level of 26 feet bgs was used in previous liquefaction analyses for the Clive Facility
(AMEC 2005, 2011, and 2012). Therefore, the upper sand Unit 3 was not considered during their
liquefaction triggering analysis. Previous calculations indicated that liquefaction of the saturated
soil layers below the site (Units 1 and 2 at the time) was not a design issue for the adjacent waste
cells. For the seismic design event analyzed, majority of the soils in the upper 30 to 60 feet of the
subsurface, Unit 2, consist of cohesive deposits, which have a low probability of liquefaction due
to their high clay content. It was also found that the interbedded cohesionless silt and silty sand
deposits in Unit 1 would be also unlikely to liquefy due to their relatively high density. Geosyntec
generally agrees with this prediction for Unit 1 and considers it applicable to the Federal
Cell Unit 1 soils, however consideration for the upper sand Unit 3 was included in the current
analysis to reflect the groundwater level rise condition that would saturate the cohesionless soils.
6.2 Seismic Design Parameters
The site-specific seismic design parameters such as PGA and Mw required for estimating
liquefaction triggering were based on the referenced seismic hazard analysis that justified
DWMRC’s 2012 license action and as discussed in Section 3.4, and are as follows:

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 PGA = 0.24g
 Mw = 7.3
6.3 Liquefaction of Sand-Like Soils
The liquefaction triggering analysis was performed following the procedures outlined in Idriss and
Boulanger (2008) for the sand-like soils in Unit 3. Sand-like soils are referred to soils which
primarily consist of coarse-grained particles more than 50 percent by weight or very low plasticity
fine-grained soils (i.e., low plasticity silts). The soils classified as clay were not considered
susceptible to liquefaction and their evaluation is discussed in following section.
Boring logs for GW-36 through GW-38 (Bingham, 1992) which were excavated with a hollow-
stem auger (HSA) and extended to depths of 30 feet bgs into proposed Federal Cell area limits
were used to complete the analysis (logs are provided in Attachment A). Due to the limitations of
HSA drilling methods in keeping the drilled hole stable for drilling at or below groundwater level,
SPT blow counts recorded at or below groundwater do not provide a meaningful representation of
the subsurface soil density. Therefore, the liquefaction triggering analysis herein only presents
results for soils with SPT blow-counts above the groundwater readings; approximately 18 to 20
feet bgs. Fines content results were not available for Unit 3 samples collected from GW-36 through
GW-38. The fines content was therefore assumed to represent a silty sand with the lower bound
fines content of 15%.
Detailed calculations for the liquefaction triggering analysis are presented in Attachment E.
Results indicate that sand-like soils within the upper 20 feet below ground surface are not
anticipated to liquefy under the design seismic loading with the exception of a thin layer between
14 and 16 feet bgs encountered in GW-38 that resulted in a FS greater than 1.0 but less than 1.1,
which indicates there is potential for localized liquefaction to occur in this layer. The potential for
seismic settlement in this layer is less than ½ an inch and localized to the location of GW-38
(Figure 1). Considering the dense nature of the sands in Unit 3, localized liquefaction will likely
induce a dilative behavior and not adversely impact the strength of the sands. Therefore, these
affects are not anticipated to undermine the stable conditions of the proposed Federal Cell.
6.4 Cyclic Softening of Clay-Like Soils
Cyclic softening is a phenomenon where fine-grained soils do not undergo liquefaction, but
experience reduction in strength and stiffness caused by cyclic deformations due to increase in
pore pressures during seismic shaking. Previous analysis concluded that cyclic softening is highly

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unlikely, presenting a very low related risk of cyclic softening (of Units 2 and 4 clay-like soils)
(AMEC, 2012). Considering that most clays in upper Unit 4 will be removed as part of construction
of the proposed Federal Cell and given the stiff nature of Unit 2 clays, Geosyntec generally agrees
with this conclusion from the DWMRC’s prior licensing decisions. Geosyntec has evaluated the
global stability of the Federal Cell for a post-earthquake event that results in 50% strength
reduction of all clay-like soils, clay-liner included representing a conservative and less likely
strength reduction scenario. The results of this stability condition are discussed in Section 4.11.
Results indicated that even a strength reduction of 50% in the clay-like soils and liner will still
yield a stable condition post-earthquake.
7. CONCLUSIONS
7.1 Global Static, Seismic Slope Stability and Deformation
Based on the results of Geosyntec’s slope stability analyses, the design of the proposed Federal
Cell will remain stable for global static short-term, long-term, seismic, and post-earthquake
conditions presented in this package. Results are presented in Attachment B. Based on the results
of the seismic deformation analysis, the design of the proposed Federal Cell slopes and cover will
not experience significant seismic induced deformations (<5 mm). Results are presented in
Attachment C.
7.2 Settlement
Based on the results of the settlement analyses, the current load of the proposed Federal Cell may
result in up to 11-inches of elastic settlement of sand-like soils, 12-inches of primary consolidation
of clay-like soils, and 6-inches of secondary compression settlement of clay-like soils. Elastic
settlement and primary consolidation settlement presented in this package should be complete
within one year after the embankment waste placement (within the required settlement monitoring
period) and is not interfere with the post-construction performance of the cover. The 6-inches of
secondary compression settlement of clay-like foundation soils should occur over a compliance
period of 10,000 years and are not projected to impact the long-term performance of the cover and
embankment. The magnitude of settlements estimated here are for the top deck portion of the
embankment where the maximum embankment height is experienced and expected to decrease
linearly over the top slopes to essentially no settlement at the toe of the embankment. Therefore,
settlement of the foundational soils as a result of construction of the Federal Cell are not expected
to adversely impact the adjacent cells. Results are presented in Attachment D.

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7.3 Liquefaction and Cyclic Softening
Based on the results of liquefaction triggering analyses and seismically-induced cyclic softening,
these hazards are not projected to undermine the stable condition of the proposed Federal Cell.
Seismically-induced settlements of the sand-like soils are negligible (<1 inch.) Cyclic softening of
the clay-like soils is highly unlikely to occur as a result of the design seismic event (0.24g PGA
and 7.3 Mw). While extremely unlikely, a 50% strength degradation of the clay-like soils would
still yield a stable slope condition post-earthquake. Results of the sand-like soils liquefaction
analysis are presented in Attachment E and the post-earthquake softened clay stability analyses are
provided in Attachment B (Figure B-9 and B-10).

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8. REFERENCES
ASTM International.
AMEC (2005). Combined Embankment Study for Class A Waste Embankment, Clive, Utah,
December 2005.
AMEC (2011). Geotechnical Update Report for Class A Waste Embankment, Clive, Utah,
February 2011.
AMEC (2012). Seismic Hazard Evaluation/Seismic Stability Analysis Update for Clive Facility,
Clive, Utah, April 2012.
Bingham Environmental (1992). Hydrogeologic Report Part 1 & 2 for Clive Facility, Clive, Utah,
July 1992.
Bingham Environmental (1992). Hydrogeologic Report Addendum 1 for Clive Facility, Clive,
Utah, June 1992.
Bingham Environmental (1992). Hydrogeologic Report Addendum 2 for Clive Facility, Clive,
Utah, July 1992.
Division of Waste Management and Radioactive Control (DWMRC) (2021). Technical Report for
Performance Objective R313-25-23 Stability of the Disposal Site after Closure, Federal Cell,
Clive, Utah.
EnergySolutions (2020). Drawings 14004 C01-05 for Federal Waste Cell, Clive Facility, Utah.
GEO-STUDIO International, Ltd. (2019). “SLOPE/W,” version 10.2.0.19483, Calgary, Canada.
Hynes-Griffin, Mary E. and Franklin, Arley G. (1984). Rationalizing the Seismic Coefficient
Method. Paper GL-84-13, Geotechnical Laboratory, Waterways Experiment Station, US
Corps of Engineers.
Idriss, I. M. and Boulanger, R. W., [2008], Soil Liquefaction During Earthquakes, Earthquake
Engineering Research Institute (EERI), Monograph 12.
Lee and Kim. (2014). Flowable Backfill Materials from Bottom Ash for Underground Pipeline.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5453207/

Page 30 of 30

Written by: M. Downing Date: 3/11/2021 Reviewed
:
B.Baturay Date: 3/17/21

Client: ES Project: Federal Cell Project/ Proposal No.: SLC1025 Task No.: 01

Neptune and Company, Inc. (Neptune) (2015). Final Report for the Clive DU PA Model v1.4,
November 2015.
Neptune (2015). Radioactive Waste Inventory for Clive DU PA Model v1.4, November 2015.
Makdisi, F.I., and H.B. Seed [1978] “Simplified Procedure for Estimating Dam and Embankment
Earthquake-Induced Deformation," Journal of the Geotechnical Engineering Division,
ASCE, Vol. 104, No. GT7, 1978, pp. 849-867.
Stantec (2020). Phase 1 Basal Depth Aquifer Study for Clive Facility, Clive, Utah, September
2020.
Seismicmaps.org
US Army Corps of Engineers (USACE) (2003). Engineering and Design Slope Stability,
Engineering Manual No. 1110-2-1902, October 2003.
Qian, et al. (2002). Geotechnical Aspects of Landfill Design and Construction.

FIGURES

SITE LAYOUT AND EXISTING EXPLORATIONS
FEDERAL CELL AT CLIVE FACILITY
CLIVE, UTAH
FIGURE NO. 1
PROJECT NO. SLC1025
DATE: MARCH 2021
Notes: 
1. Base image from the Hydrogeologic Report (Bingham, 
1992)
2. Other explorations are known to exist across Section 32 of
the Clive Facility. Explorations shown here were used for 
the Federal Cell geotechnical engineering evaluations.
GW –
(Bingham Enviro, 1992)
SC –
(D&M, 1984)
SC‐7 SC‐8
GW‐36
GW‐37
GW‐38
SC‐1
SC‐10
B‐2
B –
(AMEC, 2005)
GW‐18
GW‐17A
GW‐16
CPT‐6
CPT‐2
CPT‐1
CPT‐5
CPT‐3
CPT‐4
B‐1
CPT –
(AMEC, 2005)

ATTACHMENT A

ATTACHMENT B

2.7
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03/26/2021
Unit 2 Adjacent Road Short Term
Project No.SLC1025
Short Term Undrained GW @ Current Conditions Figure

B-1
Energy Solutions Federal Cell
Color Name Model Unit
Weight(pcf)
Cohesion
(psf)
Cohesion'
(psf)
Phi'
(°)
Piezometric
Line
Block Spec Bedrock Bedrock (Impenetrable) 1
Compacted Clay Liner (Drained)Mohr-Coulomb 123 0 28 1
Compacted Fill Mohr-Coulomb 120 300 29 1
Evaporative Layer Mohr-Coulomb 120 300 29 1
Filter Zone Mohr-Coulomb 130 0 34 1
Frost Protection Mohr-Coulomb 130 0 38 1
Liner Protective Cover Mohr-Coulomb 118 250 38 1
LLRW with CLSM Mohr-Coulomb 120 0 30 1
Radon Clay Cover Mohr-Coulomb 123 1,000 0 1
Roadbase Mohr-Coulomb 130 0 36 1
Side Rock (Rip Rap) Mohr-Coulomb 135 0 40 1
Top Slope Surface Layer Mohr-Coulomb 120 200 30 1
Unit 2 CL/ML (23-45) Undrained Undrained (Phi=0) 121 1,500 1
Unit 3 SM (9-23) Drained Mohr-Coulomb 120 0 34 1
Unit 4 CL/ML (0-9) Drained Mohr-Coulomb 118 0 29 1
2.6
Distance (ft)
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03/26/2021
Unit 2 Adjacent 11e Short Term
Project No.SLC1025
Short Term Undrained GW @ Current Conditions
Energy Solutions Federal Cell
Color Name Model Unit
Weight(pcf)
Cohesion
(psf)
Cohesion'
(psf)
Phi'
(°)
Piezometric
Line
Block Spec Bedrock Bedrock (Impenetrable) 1
Compacted Clay Liner (Drained)Mohr-Coulomb 123 0 28 1
Compacted Fill Mohr-Coulomb 120 300 29 1
Evaporative Layer Mohr-Coulomb 120 300 29 1
Filter Zone Mohr-Coulomb 130 0 34 1
Frost Protection Mohr-Coulomb 130 0 38 1
Liner Protective Cover Mohr-Coulomb 118 250 38 1
LLRW with CLSM Mohr-Coulomb 120 0 30 1
Radon Clay Cover Mohr-Coulomb 123 1,000 0 1
Roadbase Mohr-Coulomb 130 0 36 1
Side Rock (Rip Rap) Mohr-Coulomb 135 0 40 1
Top Slope Surface Layer Mohr-Coulomb 120 200 30 1
Unit 2 CL/ML (23-45) Undrained Undrained (Phi=0) 121 1,500 1
Unit 3 SM (9-23) Drained Mohr-Coulomb 120 0 34 1
Unit 4 CL/ML (0-9) Drained Mohr-Coulomb 118 0 29 1
Figure
B-2
3.4
Distance (ft)
0 100 200 300 400
El
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5
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105
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185
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Distance
0 100 200 300 400
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03/26/2021
Clay Liner Adjacent Road
Project No.SLC1025
Long Term Static Drained GW @ Current Conditions
Energy Solutions Federal Cell
Color Name Model Unit Weight(pcf)
Cohesion'(psf)Phi'(°)PiezometricLine
Block Spec Bedrock Bedrock (Impenetrable)1
Compacted Clay Liner (Drained)Mohr-Coulomb 123 0 28 1
Compacted Fill Mohr-Coulomb 120 300 29 1
Evaporative Layer Mohr-Coulomb 120 300 29 1
Filter Zone Mohr-Coulomb 130 0 34 1
Frost Protection Mohr-Coulomb 130 0 38 1
Liner Protective Cover Mohr-Coulomb 118 250 38 1
LLRW with CLSM Mohr-Coulomb 120 0 30 1
Radon Clay Cover Mohr-Coulomb 123 1,000 0 1
Roadbase Mohr-Coulomb 130 0 36 1
Side Rock (Rip Rap)Mohr-Coulomb 135 0 40 1
Top Slope Surface Layer Mohr-Coulomb 120 200 30 1
Figure

B-3
3.4
Distance (ft)
0 100 200 300 400
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5
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105
125
145
165
185
205
Distance
0 100 200 300 400
El
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03/17/2021
Unit 4 Adjacent Road Long Term Drained
Project No.SLC1025
Long Term Static Drained GW @ Rise Conditions
Energy Solutions Federal Cell
Color Name Model Unit Weight(pcf)
Cohesion'(psf)Phi'(°)PiezometricLine
Block Spec Bedrock Bedrock (Impenetrable)1
Compacted Clay Liner (Drained)Mohr-Coulomb 123 0 28 1
Compacted Fill Mohr-Coulomb 120 300 29 1
Evaporative Layer Mohr-Coulomb 120 300 29 1
Filter Zone Mohr-Coulomb 130 0 34 1
Frost Protection Mohr-Coulomb 130 0 38 1
Liner Protective Cover Mohr-Coulomb 118 250 38 1
LLRW with CLSM Mohr-Coulomb 120 0 30 1
Radon Clay Cover Mohr-Coulomb 123 1,000 0 1
Roadbase Mohr-Coulomb 130 0 36 1
Side Rock (Rip Rap) Mohr-Coulomb 135 0 40 1
Top Slope Surface Layer Mohr-Coulomb 120 200 30 1
Unit 4 CL/ML (0-9) Drained Mohr-Coulomb 118 0 29 1
Figure

B-4
3.3
Distance (ft)
1,000 1,100 1,200 1,300 1,400 1,500
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5
25
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65
85
105
125
145
165
185
205
225
245
265
Distance
1,000 1,100 1,200 1,300 1,400 1,500
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(
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03/26/2021
Clay Liner Adjacent 11e
Project No.SLC1025
Long Term Static Drained GW @ Current Conditions
Energy Solutions Federal Cell
Color Name Model Unit Weight(pcf)
Cohesion'(psf)Phi'(°)PiezometricLine
Block Spec Bedrock Bedrock (Impenetrable)1
Compacted Clay Liner (Drained)Mohr-Coulomb 123 0 28 1
Compacted Fill Mohr-Coulomb 120 300 29 1
Evaporative Layer Mohr-Coulomb 120 300 29 1
Filter Zone Mohr-Coulomb 130 0 34 1
Frost Protection Mohr-Coulomb 130 0 38 1
Liner Protective Cover Mohr-Coulomb 118 250 38 1
LLRW with CLSM Mohr-Coulomb 120 0 30 1
Radon Clay Cover Mohr-Coulomb 123 1,000 0 1
Roadbase Mohr-Coulomb 130 0 36 1
Side Rock (Rip Rap)Mohr-Coulomb 135 0 40 1
Top Slope Surface Layer Mohr-Coulomb 120 200 30 1
Figure
B-5
3.3
Distance (ft)
1,000 1,100 1,200 1,300 1,400 1,500
El
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-35
-15
5
25
45
65
85
105
125
145
165
185
205
225
245
265
Distance
1,000 1,100 1,200 1,300 1,400 1,500
El
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(
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03/19/2021
Unit 4 Adjacent 11e Long Term Drained
Project No.SLC1025
Long Term Static Drained GW @ Rise Conditions
Energy Solutions Federal Cell
Color Name Model Unit Weight(pcf)
Cohesion'(psf)Phi'(°)PiezometricLine
Block Spec Bedrock Bedrock (Impenetrable)1
Compacted Clay Liner (Drained)Mohr-Coulomb 123 0 28 1
Compacted Fill Mohr-Coulomb 120 300 29 1
Evaporative Layer Mohr-Coulomb 120 300 29 1
Filter Zone Mohr-Coulomb 130 0 34 1
Frost Protection Mohr-Coulomb 130 0 38 1
Liner Protective Cover Mohr-Coulomb 118 250 38 1
LLRW with CLSM Mohr-Coulomb 120 0 30 1
Radon Clay Cover Mohr-Coulomb 123 1,000 0 1
Roadbase Mohr-Coulomb 130 0 36 1
Side Rock (Rip Rap) Mohr-Coulomb 135 0 40 1
Top Slope Surface Layer Mohr-Coulomb 120 200 30 1
Unit 4 CL/ML (0-9) Drained Mohr-Coulomb 118 0 29 1
Figure
B-6
1.3
Distance (ft)
50 100 150 200 250 300 350 400 450 500 550 600 650 700 750
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Distance
50 100 150 200 250 300 350 400 450 500 550 600 650 700 750
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Unit 4 Adjacent Road Seismic
Project No.SLC1025
Pseudostatic Undrained GW @ Rise Conditions Figure

B-7
Energy Solutions Federal Cell
Color Name Model Unit Weight(pcf)
Cohesion'(psf)Phi'(°)Cohesion(psf)PiezometricLine
Block Spec Bedrock Bedrock (Impenetrable) 1
Compacted Clay Liner (Undrained)Undrained (Phi=0) 123 1,000 1
Compacted Fill Mohr-Coulomb 120 300 29 1
Evaporative Layer Mohr-Coulomb 120 300 29 1
Filter Zone Mohr-Coulomb 130 0 34 1
Frost Protection Mohr-Coulomb 130 0 38 1
Liner Protective Cover Mohr-Coulomb 118 250 38 1
LLRW with CLSM Mohr-Coulomb 120 0 30 1
Radon Clay Cover Mohr-Coulomb 123 1,000 0 1
Roadbase Mohr-Coulomb 130 0 36 1
Side Rock (Rip Rap) Mohr-Coulomb 135 0 40 1
Top Slope Surface Layer Mohr-Coulomb 120 200 30 1
Unit 4 CL/ML (0-9) Undrained Undrained (Phi=0) 118 1,000 1
1.3
Distance (ft)
750 800 850 900 950 1,000 1,050 1,100 1,150 1,200 1,250 1,300 1,350 1,400 1,450
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Distance
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Unit 4 Adjacent 11e Seismic
Project No.SLC1025
Figure

B-8
Pseudostatic Undrained GW @ Rise Conditions
Energy Solutions Federal Cell
Color Name Model Unit Weight(pcf)
Cohesion'(psf)Phi'(°)Cohesion(psf)PiezometricLine
Block Spec Bedrock Bedrock (Impenetrable) 1
Compacted Clay Liner (Undrained)Undrained (Phi=0) 123 1,000 1
Compacted Fill Mohr-Coulomb 120 300 29 1
Evaporative Layer Mohr-Coulomb 120 300 29 1
Filter Zone Mohr-Coulomb 130 0 34 1
Frost Protection Mohr-Coulomb 130 0 38 1
Liner Protective Cover Mohr-Coulomb 118 250 38 1
LLRW with CLSM Mohr-Coulomb 120 0 30 1
Radon Clay Cover Mohr-Coulomb 123 1,000 0 1
Roadbase Mohr-Coulomb 130 0 36 1
Side Rock (Rip Rap) Mohr-Coulomb 135 0 40 1
Top Slope Surface Layer Mohr-Coulomb 120 200 30 1
Unit 4 CL/ML (0-9) Undrained Undrained (Phi=0) 118 1,000 1
1.8
Distance (ft)
0 100 200 300 400
El
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6
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66
86
106
126
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166
186
206
Distance
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03/17/2021
Unit 4 Adjacent Road Softened
Project No.SLC1025
Undrained Clay Like Soils GW @ Rise Conditions (Cyclic Softening)
Energy Solutions Federal Cell
Color Name Model Unit Weight(pcf)
Cohesion'(psf)Phi'(°)Cohesion(psf)PiezometricLine
Block Spec Bedrock Bedrock (Impenetrable) 1
Compacted Clay Liner (Undrained)Undrained (Phi=0) 123 1,000 1
Compacted Clay Liner Undrained Cyclic
Softening
Undrained (Phi=0) 123 500 1
Compacted Fill Mohr-Coulomb 120 300 29 1
Evaporative Layer Mohr-Coulomb 120 300 29 1
Filter Zone Mohr-Coulomb 130 0 34 1
Frost Protection Mohr-Coulomb 130 0 38 1
Liner Protective Cover Mohr-Coulomb 118 250 38 1
LLRW with CLSM Mohr-Coulomb 120 0 30 1
Radon Clay Cover Mohr-Coulomb 123 1,000 0 1
Roadbase Mohr-Coulomb 130 0 36 1
Side Rock (Rip Rap) Mohr-Coulomb 135 0 40 1
Top Slope Surface
Layer
Mohr-Coulomb 120 200 30 1
Unit 4 CL/ML (0-9) Undrained Cyclic Softening
Undrained (Phi=0) 118 500 1
Figure
B-9
1.6
Distance (ft)
1,000 1,100 1,200 1,300 1,400 1,500
El
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-74
-54
-34
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26
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106
126
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166
186
206
Distance
1,000 1,100 1,200 1,300 1,400 1,500
El
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03/17/2021
Unit 4 Adjacent 11e Softened
Project No.SLC1025
Undrained Clay Like Soils GW @ Rise Conditions (Cyclic Softening)
Energy Solutions Federal Cell
Figure
B-10
Color Name Model Unit Weight(pcf)
Cohesion'(psf)Phi'(°)Cohesion(psf)PiezometricLine
Block Spec Bedrock Bedrock (Impenetrable) 1
Compacted Clay Liner (Undrained)Undrained (Phi=0) 123 1,000 1
Compacted Clay Liner Undrained Cyclic Softening
Undrained (Phi=0) 123 500 1
Compacted Fill Mohr-Coulomb 120 300 29 1
Evaporative Layer Mohr-Coulomb 120 300 29 1
Filter Zone Mohr-Coulomb 130 0 34 1
Frost Protection Mohr-Coulomb 130 0 38 1
Liner Protective Cover Mohr-Coulomb 118 250 38 1
LLRW with CLSM Mohr-Coulomb 120 0 30 1
Radon Clay Cover Mohr-Coulomb 123 1,000 0 1
Roadbase Mohr-Coulomb 130 0 36 1
Side Rock (Rip Rap) Mohr-Coulomb 135 0 40 1
Top Slope Surface Layer Mohr-Coulomb 120 200 30 1
Unit 4 CL/ML (0-9) Undrained Cyclic Softening
Undrained (Phi=0) 118 500 1

ATTACHMENT C

SLC1025
Earthquake Deformation AnalysisMakdisi & Seed Simplified Method
Case/Description ky ümax y (ft) H (ft) y/H kmax/ümax kmax ky/kmax Deformation
(cm)
Deformation
(mm)
Allowable
Deformation
(mm)
FS 1 Critical Section Failure Through Unit 4, entire slope face (y/h =1), adjacent 11(e) 0.180 0.580 52.0 52.0 1.0 0.34 0.20 0.91 0.4 4 150-300
Mw:7.3
PHGA (g):0.24 -
-
umax= 0.58
Makdisi and Seed - deformation analysis md

ATTACHMENT D

Site:CLIVE FEDERAL CELL Project No.:SLC1025
Location:CLIVE UTAH
Client:ES Date:17‐Mar‐21
Prepared by:M.Downing Reviewed by:B.Baturay
Theory
Total settlement made up of three (3) components:
Total Settlement st = Immediate Settlement (si) + Primary Consolidation (sc) + Secondary Settlement (ss)
Primary Consolidation sc
S = Cr Ho(1+eo) log['c/'vo] + Cc Ho1+eo log[('vo + v)/'c]
where Cr =recompression index
Cc = compression index
Ho = initial soil layer thickness'c = effective preconsolidation pressure = OCR 'vo    'vo = initial effective vertical stressv = change in vertical effective stress
eo=initial void ratio
Secondary Settlement ss
ss = C H100 log(t2/t1)
where C = secondary compression index
Ho = thickness of compressible layer at end of primary consolidation
t2 = time for which secondary settlements are calculated (500 years for design life, assume settlement after that is minimul due to log scale projection of creep)
t1 = t100 for primary consolidation - 1 year - estimated by previous analyses of Unit 2 and 4 clay layers (AMEC)
Elastic (Immediate)Ze=Δσ/Ms *Ho
wher Z =elastic settlement of soil layer
Ho= initial thickness of soil layer
Δσ= change in stress in layerMs = constrained modulus of soil estimated with E and v of the insitu soil
CALCULATIONS
Height of Waste and Cover Materials=52.5ft at the tallest point, including coverNew Load for Foundation Average Unit Weight of Cover and Waste=120.0pcf
width B v from Loading =6300.0psf
Depth (FT BGS)B =1225.0ft Based on Cell Limits v Unit 4 L =1920.0ft
CL/ML 2 Unit 4 Unit Weight 118.0pcf
Unit 3 Unit 3 Unit Weight 120.0pcf
SM 16 Unit 2 Unit Weight 121.0pcf
Unit 2 Unit 1 Unit Weight 120.0pcf
CL/ML Unit weight of water 62.4pcf
38 Depth to Water =18.0ft gw @ 25' below current grade, approximately 7 feet of upper material to be removed = 16 feet bgs for modeling
Unit 1
SM Unit 4 Cc =0.250Unit 4 eo =1.1 Unit 3 Ms =311,040
Unit 4 Cr =0.02Unit 2 eo =1.2 Unit 1 Ms=531556
100 Unit 4 Cαε =0.004Unit 4 OCR =5
t1 (t100 for primary
consolidation)1
Unit 2 OCR =1.5
 (comp ance 
period of 10,000 
years f)10000
Unit 2 Cc= 0.2
Unit 2 Cr =0.025Unit 2 Cαε =0.00450
Depth (ft)
Depth of 
Midpt (ft)vo (psf)u (psf)'vo (psf)
Effective Mat 
Area
(sf)
v (psf)
'vo +v (psf) OCR 'c (psf)Ho (ft)'vo +v < σ'c Sconsolidation (ft) H100 Ssecondary (ft)S c+s (ft) Ze (ft)
0.0 6300.0
1.0 0.5 59.0 59.0 2353572.8 6295.8 6354.8 5.0 295.0 1.0 no 0.160 0.840 0.013 0.173
2.0 1.5 177.0 177.0 2356719.8 6287.4 6464.4 5.0 885.0 1.0 no 0.104 0.896 0.014 0.118
3.0 2.5 297.0 297.0 2359868.8 6279.0 6576.0 1.0 0.020
4.0 3.5 417.0 417.0 2363019.8 6270.6 6687.6 1.0 0.020
5.0 4.5 537.0 537.0 2366172.8 6262.3 6799.3 1.0 0.020
6.0 5.5 657.0 657.0 2369327.8 6253.9 6910.9 1.0 0.020
7.0 6.5 777.0 777.0 2372484.8 6245.6 7022.6 1.0 0.020
8.0 7.5 897.0 897.0 2375643.8 6237.3 7134.3 1.0 0.020
9.0 8.5 1017.0 1017.0 2378804.8 6229.0 7246.0 1.0 0.020
10.0 9.5 1137.0 1137.0 2381967.8 6220.7 7357.7 1.0 0.020
11.0 10.5 1257.0 1257.0 2385132.8 6212.5 7469.5 1.0 0.020
12.0 11.5 1377.0 1377.0 2388299.8 6204.2 7581.2 1.0 0.020
13.0 12.5 1497.0 1497.0 2391468.8 6196.0 7693.0 1.0 0.020
14.0 13.5 1617.0 1617.0 2394639.8 6187.8 7804.8 1.0 0.020
15.0 14.5 1737.0 1737.0 2397812.8 6179.6 7916.6 1.0 0.020
16.0 15.5 1857.0 1857.0 2400987.8 6171.5 8028.5 1.0 0.020
17.0 16.5 1978.0 1978.0 2404164.8 6163.3 8141.3 1.5 2967.0 1.0 no 0.042 0.958 0.017 0.05918.0 17.5 2099.0 2099.0 2407343.8 6155.2 8254.2 1.5 3148.5 1.0 no 0.040 0.960 0.017 0.05719.0 18.5 2220.0 31.2 2188.8 2410524.8 6147.0 8335.8 1.5 3283.2 1.0 no 0.039 0.961 0.017 0.056
20.0 19.5 2341.0 93.6 2247.4 2413707.8 6138.9 8386.3 1.5 3371.1 1.0 no 0.038 0.962 0.017 0.05521.0 20.5 2462.0 156.0 2306.0 2416892.8 6130.8 8436.8 1.5 3459.0 1.0 no 0.037 0.963 0.017 0.055
22.0 21.5 2583.0 218.4 2364.6 2420079.8 6122.8 8487.4 1.5 3546.9 1.0 no 0.036 0.964 0.017 0.05423.0 22.5 2704.0 280.8 2423.2 2423268.8 6114.7 8537.9 1.5 3634.8 1.0 no 0.036 0.964 0.017 0.05324.0 23.5 2825.0 343.2 2481.8 2426459.8 6106.7 8588.5 1.5 3722.7 1.0 no 0.035 0.965 0.017 0.052
25.0 24.5 2946.0 405.6 2540.4 2429652.8 6098.6 8639.0 1.5 3810.6 1.0 no 0.034 0.966 0.017 0.05226.0 25.5 3067.0 468.0 2599.0 2432847.8 6090.6 8689.6 1.5 3898.5 1.0 no 0.034 0.966 0.017 0.051
27.0 26.5 3188.0 530.4 2657.6 2436044.8 6082.6 8740.2 1.5 3986.4 1.0 no 0.033 0.967 0.017 0.05028.0 27.5 3309.0 592.8 2716.2 2439243.8 6074.7 8790.9 1.5 4074.3 1.0 no 0.032 0.968 0.017 0.05029.0 28.5 3430.0 655.2 2774.8 2442444.8 6066.7 8841.5 1.5 4162.2 1.0 no 0.032 0.968 0.017 0.049
30.0 29.5 3551.0 717.6 2833.4 2445647.8 6058.8 8892.2 1.5 4250.1 1.0 no 0.031 0.969 0.017 0.04931.0 30.5 3672.0 780.0 2892.0 2448852.8 6050.8 8942.8 1.5 4338.0 1.0 no 0.031 0.969 0.017 0.048
32.0 31.5 3793.0 842.4 2950.6 2452059.8 6042.9 8993.5 1.5 4425.9 1.0 no 0.030 0.970 0.017 0.04733.0 32.5 3914.0 904.8 3009.2 2455268.8 6035.0 9044.2 1.5 4513.8 1.0 no 0.029 0.971 0.017 0.04734.0 33.5 4035.0 967.2 3067.8 2458479.8 6027.1 9094.9 1.5 4601.7 1.0 no 0.029 0.971 0.017 0.046
35.0 34.5 4156.0 1029.6 3126.4 2461692.8 6019.3 9145.7 1.5 4689.6 1.0 no 0.028 0.972 0.017 0.04636.0 35.5 4277.0 1092.0 3185.0 2464907.8 6011.4 9196.4 1.5 4777.5 1.0 no 0.028 0.972 0.017 0.045
37.0 36.5 4398.0 1154.4 3243.6 2468124.8 6003.6 9247.2 1.5 4865.4 1.0 no 0.027 0.973 0.018 0.04538.0 37.5 4519.0 1216.8 3302.2 2471343.8 5995.8 9298.0 1.5 4953.3 1.0 no 0.027 0.973 0.018 0.04439.0 38.5 4639.0 1279.2 3359.8 2474564.8 5988.0 9347.8 1.0 0.011
40.0 39.5 4759.0 1341.6 3417.4 2477787.8 5980.2 9397.6 1.0 0.01141.0 40.5 4879.0 1404.0 3475.0 2481012.8 5972.4 9447.4 1.0 0.011
42.0 41.5 4999.0 1466.4 3532.6 2484239.8 5964.6 9497.2 1.0 0.01143.0 42.5 5119.0 1528.8 3590.2 2487468.8 5956.9 9547.1 1.0 0.01144.0 43.5 5239.0 1591.2 3647.8 2490699.8 5949.2 9597.0 1.0 0.011
45.0 44.5 5359.0 1653.6 3705.4 2493932.8 5941.5 9646.9 1.0 0.01146.0 45.5 5479.0 1716.0 3763.0 2497167.8 5933.8 9696.8 1.0 0.011
47.0 46.5 5599.0 1778.4 3820.6 2500404.8 5926.1 9746.7 1.0 0.01148.0 47.5 5719.0 1840.8 3878.2 2503643.8 5918.4 9796.6 1.0 0.011
SETTLEMENT ANALYSES
Depth (ft)Depth of 
Midpt (ft)vo (psf)u (psf)'vo (psf)
Effective Mat 
Area
(sf)
v (psf)
'vo +v (psf) OCR 'c (psf)Ho (ft)'vo +v < σ'c Sconsolidation (ft) H100 Ssecondary (ft)S c+s (ft) Ze (ft)
49.0 48.5 5839.0 1903.2 3935.8 2506884.8 5910.8 9846.6 1.0 0.011
50.0 49.5 5959.0 1965.6 3993.4 2510127.8 5903.1 9896.5 1.0 0.011
51.0 50.5 6079.0 2028.0 4051.0 2513372.8 5895.5 9946.5 1.0 0.01152.0 51.5 6199.0 2090.4 4108.6 2516619.8 5887.9 9996.5 1.0 0.011
53.0 52.5 6319.0 2152.8 4166.2 2519868.8 5880.3 10046.5 1.0 0.01154.0 53.5 6439.0 2215.2 4223.8 2523119.8 5872.7 10096.5 1.0 0.011
55.0 54.5 6559.0 2277.6 4281.4 2526372.8 5865.2 10146.6 1.0 0.011
56.0 55.5 6679.0 2340.0 4339.0 2529627.8 5857.6 10196.6 1.0 0.01157.0 56.5 6799.0 2402.4 4396.6 2532884.8 5850.1 10246.7 1.0 0.011
58.0 57.5 6919.0 2464.8 4454.2 2536143.8 5842.6 10296.8 1.0 0.01159.0 58.5 7039.0 2527.2 4511.8 2539404.8 5835.1 10346.9 1.0 0.011
60.0 59.5 7159.0 2589.6 4569.4 2542667.8 5827.6 10397.0 1.0 0.011
61.0 60.5 7279.0 2652.0 4627.0 2545932.8 5820.1 10447.1 1.0 0.01162.0 61.5 7399.0 2714.4 4684.6 2549199.8 5812.6 10497.2 1.0 0.011
63.0 62.5 7519.0 2776.8 4742.2 2552468.8 5805.2 10547.4 1.0 0.01164.0 63.5 7639.0 2839.2 4799.8 2555739.8 5797.8 10597.6 1.0 0.011
65.0 64.5 7759.0 2901.6 4857.4 2559012.8 5790.4 10647.8 1.0 0.011
66.0 65.5 7879.0 2964.0 4915.0 2562287.8 5783.0 10698.0 1.0 0.01167.0 66.5 7999.0 3026.4 4972.6 2565564.8 5775.6 10748.2 1.0 0.011
68.0 67.5 8119.0 3088.8 5030.2 2568843.8 5768.2 10798.4 1.0 0.01169.0 68.5 8239.0 3151.2 5087.8 2572124.8 5760.8 10848.6 1.0 0.011
70.0 69.5 8359.0 3213.6 5145.4 2575407.8 5753.5 10898.9 1.0 0.011
71.0 70.5 8479.0 3276.0 5203.0 2578692.8 5746.2 10949.2 1.0 0.01172.0 71.5 8599.0 3338.4 5260.6 2581979.8 5738.9 10999.5 1.0 0.011
73.0 72.5 8719.0 3400.8 5318.2 2585268.8 5731.6 11049.8 1.0 0.01174.0 73.5 8839.0 3463.2 5375.8 2588559.8 5724.3 11100.1 1.0 0.011
75.0 74.5 8959.0 3525.6 5433.4 2591852.8 5717.0 11150.4 1.0 0.011
76.0 75.5 9079.0 3588.0 5491.0 2595147.8 5709.7 11200.7 1.0 0.01177.0 76.5 9199.0 3650.4 5548.6 2598444.8 5702.5 11251.1 1.0 0.011
78.0 77.5 9319.0 3712.8 5606.2 2601743.8 5695.3 11301.5 1.0 0.01179.0 78.5 9439.0 3775.2 5663.8 2605044.8 5688.0 11351.8 1.0 0.011
80.0 79.5 9559.0 3837.6 5721.4 2608347.8 5680.8 11402.2 1.0 0.011
81.0 80.5 9679.0 3900.0 5779.0 2611652.8 5673.6 11452.6 1.0 0.01182.0 81.5 9799.0 3962.4 5836.6 2614959.8 5666.5 11503.1 1.0 0.011
83.0 82.5 9919.0 4024.8 5894.2 2618268.8 5659.3 11553.5 1.0 0.01184.0 83.5 10039.0 4087.2 5951.8 2621579.8 5652.2 11604.0 1.0 0.011
85.0 84.5 10159.0 4149.6 6009.4 2624892.8 5645.0 11654.4 1.0 0.011
86.0 85.5 10279.0 4212.0 6067.0 2628207.8 5637.9 11704.9 1.0 0.01187.0 86.5 10399.0 4274.4 6124.6 2631524.8 5630.8 11755.4 1.0 0.011
88.0 87.5 10519.0 4336.8 6182.2 2634843.8 5623.7 11805.9 1.0 0.01189.0 88.5 10639.0 4399.2 6239.8 2638164.8 5616.6 11856.4 1.0 0.011
90.0 89.5 10759.0 4461.6 6297.4 2641487.8 5609.6 11907.0 1.0 0.011
91.0 90.5 10879.0 4524.0 6355.0 2644812.8 5602.5 11957.5 1.0 0.01192.0 91.5 10999.0 4586.4 6412.6 2648139.8 5595.5 12008.1 1.0 0.011
93.0 92.5 11119.0 4648.8 6470.2 2651468.8 5588.4 12058.6 1.0 0.011

ATTACHMENT E

LIQUEFACTION SUSCEPTIBILITY EVALUATION[1]
Project: SLC Federal Cell Clive Fa Project Number: SLC1025 Checked by:
Location: Salt Lake City, Utah Prepared By: M.Downing Date: 3/11/2021
Boring: GW-36 Hammer Type: Automatic 140 lb./30-in. amax (ground surface): 0.24 g
Date: Drilling Method: Hollow Stem Auger Earthquake Magnitude: 7.3 [3]
By: Overland Drilling Ground Elevation (ft)[2]: 0.00 MSF: 1.05 [4]
Assumed depth to groundwater at time of earthquake (ft)[24]: 0.0
Assumed depth to groundwater at time of drilling (ft)[24]: 20.6
Depth Elevation Soil Unit
Weight
Borehole
Diameter ER[5]Nfield v
v', during
drilling
v', during
EQ[24]N60
(ft) (ft) (pcf) (mm) (%) (blows/ft) (psf) (psf) (psf)Crod[6]Cener [7]Cb[8]Cs[9]CSPT[10](blows/ft)
0 0.0
12.0 -12.0 118 Unit 4 Silty CLAY CL 108.0 SPT 72 9 1416 1416 667 0.80 1.20 1.00 1.00 1.00 9
14.0 -14.0 120 Unit 3 Silty Sand SM 108.0 SPT 72 55 1656 1656 782 0.85 1.20 1.00 1.00 1.00 56
16.0 -16.0 120 Unit 3 Silty Sand SM 108.0 SPT 72 61 1896 1896 898 0.85 1.20 1.00 1.00 1.00 62
18.0 -18.0 120 Unit 3 Silty Sand SM 108.0 SPT 72 32 2136 2136 1013 0.85 1.20 1.00 1.00 1.00 33
Notes:
[1]Evaluation is based on: "Idriss and Boulanger (2008), Soil Liquefaction During Earthquakes , EERI Monograph MNO-12"
[2] Boring location known to exist somewhere in Section 32 of the Clive Facility
[3]amax and earthquake magnitude based on parameters presented in the seismis hazard analysis by AMEC 2012
[4] ``
[5]Estimated to result in Cenergy of 0.8 assuming Autohammer
[6]Crod accounts for short rod correction (<1 if rod length < 10 meters) (Table 3, I&B 2008)
[7]Cenergy accounts for rod energy delivered to sampler (Table 3, I&B 2008)
[8]Cb accounts for the effect of the size of the borehole (Table 3, I&B 2008)
[9]s accounts or t e e ect o t e ners n t e samp er a e ,
[10]CSPT is a correction factor to adjust the blow counts recorded with MOD-CAL samplers to equivalent SPT blow count values.
CSPT is assumed to be 1.0 for SPT samples and 0.60 for MOD-CAL samples based on an outside diameter of 3.0 inches
and an inside diameter of 2.4 inches (Burmister, 1948)
[11]m=0.784-0.0768sqrt((N1)60cs)0.264 is iteratively calculated until (N1)60cs converges (Equation 33 and 39, I&B 2008)
[12]CN=(Pa/σ'v)1.7 accounts for effective overburden stress (Equation 33, I&B 2008)
23-Dec-91
Soil Unit USCS
Class Sample Type
Nfield Correction Factors
Page 1 GW-36
Boring: GW-36 (continued from previous page)
Date:
By: Overland Drilling
Fines
Content [11] [12](N1)60[13](N1)60cs[15][16] [17] [18] [19] [20] [21] [22] [25] [27] [28] [29] [30] [31] [32]
%m CN (blows/ft) (blows/ft) rd Cσ KCRRM7.5,'vc CSRM7.5,'vc Δ(N1)60-FC (N1)60CS-Sr FS γlim Fα γmax ΔHi εv Δsi Cum Settle
0.00
100.0 Est 0.477 1.21 10 5.5 16 -0.17 0.02 0.97 0.115 1.100 0.16 0.277 5 15 0.59
15.0 Est 0.264 1.07 60 3.3 63 -0.22 0.02 0.96 0.300 1.100 50.00 0.274 1 61 182.15
15.0 Est 0.264 1.03 64 3.3 67 -0.26 0.03 0.96 0.300 1.100 50.00 0.272 1 65 183.97
15.0 Est 0.324 1.00 33 3.3 36 -0.30 0.03 0.95 0.275 1.100 1.32 0.269 1 34 4.90
Settlement 0.00 ft
Settlement 0.0 in
[13](N1)60=N60*CN is the overburden corrected penetration resistance (Equation 31, I&B 2008)
[14](N1)60=exp[1.63+(9.7/(FC+0.1))-(15.7/(FC+0.01))2] represents the change in (N1)60 with fines content (Equation 76, I&B 2008)
[15](N1)60cs=(N1)60 + (N1)60 is the equivalent clean-sand SPT penetration resistance (Equation 75, I&B 2008)
[16](z) = -1.012-1.126sin((z/11.73)+5.133) in which z is depth in meters (Equation 23, I&B 2008)
[17](z) = 0.106+0.118sin((z/11.28)+5.142) in which z is depth in meters (Equation 24, I&B 2008)
[18]rd=exp[α(z)+β(z)M] is shear stress reduction coefficient (Equation 22, I&B 2008)
[19]Cσ=1/(18.9-2.55sqrt[(N1)60cs]0.3 is the coefficient for K (Equation 56, I&B 2008)
[20]K = 1-Cσln(vo'/Pa)1.1 is the overburden correction factor (Equation 54, I&B 2008)
[21]M7.5,'vc s t e er ve corre at on etween an correcte penetrat on res stance quat on ,
[22]CSRM7.5,'vc=0.65(amax/g)(v/v')rd(1/MSF)(1/Kσ) is the equivalent CSR for the reference values of M=7.5 and 'vc=1 atm (Equation 69, I&B 2008)
[23] NL = non-liquefiable; L = potentially liquefiable
[24] Groundwater assumed to be at a depth of 170 feet below ground surface during the field investigation (for blow count correction)
[25] Fines content correction for liquefied shear strength from Seed 1987 (Table 4, pg 126, I&B 2008)
[26] MOD-CAL refers to 2.5-inch ID sampler
[27]γlim = 1.859[1.1 - sqrt((N1)60cs/46)]3 > 0 but less than 50% = limiting shear strain (Equation 86, I&B, 2008)
[28]Fα = 0.032 + 0.69sqrt[(N1)60cs] - 0.13(N1)60cs, where (N1)60cs is limited to values > 7 (Equation 93, I&B, 2008)
[29]γmax = min[γlim, 0.35(2-FS)((1-Fα)/(FS-Fα)] for 2 > FS > Fα; if FS < Fα, γmax = γlim (Equations 91 & 92, I&B, 2008)
[30]ΔHi = Layer thickness (ft)
[31]εv = 1.5exp(-0.369sqrt[(N1)60cs] x [min(0.08, γmax )] = post liquefaction volumetric strain (Equation 96, I&B, 2008)
[32]ΔSi = (Δhi)(εv)
Δ(N1)60[14]
23-Dec-91
Fines
Content
Method
Page 2 GW-36
LIQUEFACTION SUSCEPTIBILITY EVALUATION[1]
Project: SLC Federal Cell Clive Fa Project Number: SLC1025 Checked by:
Location: Salt Lake City, Utah Prepared By: M.Downing Date:
Boring: GW-37 Hammer Type: Automatic 140 lb./30-in. amax (ground surface): 0.24 g
Date: Drilling Method: Hollow Stem Auger Earthquake Magnitude: 7.3 [3]
By: Overland Drilling Ground Elevation (ft)[2]: 0.00 MSF: 1.05 [4]
Assumed depth to groundwater at time of earthquake (ft)[24]: 0.0
Assumed depth to groundwater at time of drilling (ft)[24]: 19.2
Depth Elevation Soil Unit
Weight
Borehole
Diameter ER[5]Nfield v
v', during
drilling
v', during
EQ[24]N60
(ft) (ft) (pcf) (mm) (%) (blows/ft) (psf) (psf) (psf)Crod[6]Cener [7]Cb[8]Cs[9]CSPT[10](blows/ft)
0 0.0
7.0 -7.0 118 Unit 4 Silty CLAY CL 108.0 SPT 72 11 826 826 389 0.75 1.20 1.00 1.00 1.00 10
10.0 -10.0 120 Unit 3 Silty Sand SM 108.0 SPT 72 27 1186 1186 562 0.80 1.20 1.00 1.00 1.00 26
12.0 -12.0 120 Unit 3 Silty Sand SM 108.0 SPT 72 25 1426 1426 677 0.80 1.20 1.00 1.00 1.00 24
14.0 -14.0 120 Unit 3 Silty Sand SM 108.0 SPT 72 29 1666 1666 792 0.85 1.20 1.00 1.00 1.00 30
16.0 -16.0 120 CLAY lens CL 108.0 SPT 72 22 1906 1906 908 0.85 1.20 1.00 1.00 1.00 22
17.0 -17.0 120 Unit 3 Silty Sand SM 108.0 SPT 72 30 2026 2026 965 0.85 1.20 1.00 1.00 1.00 31
Notes:
[1]Evaluation is based on: "Idriss and Boulanger (2008), Soil Liquefaction During Earthquakes , EERI Monograph MNO-12"
[2] Boring location known to exist somewhere in Section 32 of the Clive Facility
[3]amax and earthquake magnitude based on parameters presented in the seismis hazard analysis by AMEC 2012
[4] ``
[5]Estimated to result in Cenergy of 0.8 assuming Autohammer
[6]Crod accounts for short rod correction (<1 if rod length < 10 meters) (Table 3, I&B 2008)
[7]Cenergy accounts for rod energy delivered to sampler (Table 3, I&B 2008)
[8]Cb accounts for the effect of the size of the borehole (Table 3, I&B 2008)
[9]s accounts or t e e ect o t e ners n t e samp er a e ,
[10]CSPT is a correction factor to adjust the blow counts recorded with MOD-CAL samplers to equivalent SPT blow count values.
CSPT is assumed to be 1.0 for SPT samples and 0.60 for MOD-CAL samples based on an outside diameter of 3.0 inches
and an inside diameter of 2.4 inches (Burmister, 1948)
[11]m=0.784-0.0768sqrt((N1)60cs)0.264 is iteratively calculated until (N1)60cs converges (Equation 33 and 39, I&B 2008)
[12]CN=(Pa/σ'v)1.7 accounts for effective overburden stress (Equation 33, I&B 2008)
23-Dec-91
Soil Unit USCS
Class Sample Type
Nfield Correction Factors
Page 3 GW-37
Boring: GW-37 (continued from previous page)
Date:
By: Overland Drilling
Fines
Content [11] [12](N1)60[13](N1)60cs[15][16] [17] [18] [19] [20] [21] [22] [25] [27] [28] [29] [30] [31] [32]
%m CN (blows/ft) (blows/ft) rd Cσ KCRRM7.5,'vc CSRM7.5,'vc Δ(N1)60-FC (N1)60CS-Sr FS γlim Fα γmax ΔHi εv Δsi Cum Settle
0.00
100.0 Est 0.437 1.51 15 5.5 20 -0.08 0.01 0.99 0.136 1.100 0.21 0.282 5 20 0.75 0.00
15.0 Est 0.332 1.21 31 3.3 35 -0.14 0.02 0.98 0.257 1.100 1.04 0.278 1 32 3.73
15.0 Est 0.357 1.15 28 3.3 31 -0.17 0.02 0.97 0.212 1.100 0.55 0.275 1 29 1.99
15.0 Est 0.328 1.08 32 3.3 35 -0.22 0.02 0.96 0.266 1.100 1.17 0.273 1 33 4.29
100.0 Est 0.372 1.04 23 5.5 29 -0.26 0.03 0.96 0.192 1.100 0.42 0.270 5 28 1.55
15.0 Est 0.334 1.01 31 3.3 34 -0.28 0.03 0.95 0.252 1.100 0.96 0.269 1 32 3.59
Settlement 0.00 ft
[13](N1)60=N60*CN is the overburden corrected penetration resistance (Equation 31, I&B 2008)Settlement 0.0 in
[14](N1)60=exp[1.63+(9.7/(FC+0.1))-(15.7/(FC+0.01))2] represents the change in (N1)60 with fines content (Equation 76, I&B 2008)
[15](N1)60cs=(N1)60 + (N1)60 is the equivalent clean-sand SPT penetration resistance (Equation 75, I&B 2008)
[16](z) = -1.012-1.126sin((z/11.73)+5.133) in which z is depth in meters (Equation 23, I&B 2008)
[17](z) = 0.106+0.118sin((z/11.28)+5.142) in which z is depth in meters (Equation 24, I&B 2008)
[18]rd=exp[α(z)+β(z)M] is shear stress reduction coefficient (Equation 22, I&B 2008)
[19]Cσ=1/(18.9-2.55sqrt[(N1)60cs]0.3 is the coefficient for K (Equation 56, I&B 2008)
[20]K = 1-Cσln(vo'/Pa)1.1 is the overburden correction factor (Equation 54, I&B 2008)
[21]M7.5,'vc s t e er ve corre at on etween an correcte penetrat on res stance quat on ,
[22]CSRM7.5,'vc=0.65(amax/g)(v/v')rd(1/MSF)(1/Kσ) is the equivalent CSR for the reference values of M=7.5 and 'vc=1 atm (Equation 69, I&B 2008)
[23] NL = non-liquefiable; L = potentially liquefiable
[24] Groundwater assumed to be at a depth of 170 feet below ground surface during the field investigation (for blow count correction)
[25] Fines content correction for liquefied shear strength from Seed 1987 (Table 4, pg 126, I&B 2008)
[26] MOD-CAL refers to 2.5-inch ID sampler
[27]γlim = 1.859[1.1 - sqrt((N1)60cs/46)]3 > 0 but less than 50% = limiting shear strain (Equation 86, I&B, 2008)
[28]Fα = 0.032 + 0.69sqrt[(N1)60cs] - 0.13(N1)60cs, where (N1)60cs is limited to values > 7 (Equation 93, I&B, 2008)
[29]γmax = min[γlim, 0.35(2-FS)((1-Fα)/(FS-Fα)] for 2 > FS > Fα; if FS < Fα, γmax = γlim (Equations 91 & 92, I&B, 2008)
[30]ΔHi = Layer thickness (ft)
[31]εv = 1.5exp(-0.369sqrt[(N1)60cs] x [min(0.08, γmax )] = post liquefaction volumetric strain (Equation 96, I&B, 2008)
[32]ΔSi = (Δhi)(εv)
Δ(N1)60[14]
23-Dec-91
Fines
Content
Method
Page 4 GW-37
LIQUEFACTION SUSCEPTIBILITY EVALUATION[1]
Project: SLC Federal Cell Clive Fa Project Number: SLC1025 Checked by:
Location: Salt Lake City, Utah Prepared By: M.Downing Date:
Boring: GW-38 Hammer Type: Automatic 140 lb./30-in. amax (ground surface): 0.24 g
Date: Drilling Method: Hollow Stem Auger Earthquake Magnitude: 7.3 [3]
By: Overland Drilling Ground Elevation (ft)[2]: 0.00 MSF: 1.05 [4]
Assumed depth to groundwater at time of earthquake (ft)[24]: 0.0
Assumed depth to groundwater at time of drilling (ft)[24]: 20.7
Depth Elevation Soil Unit
Weight
Borehole
Diameter ER[5]Nfield v
v', during
drilling
v', during
EQ[24]N60
(ft) (ft) (pcf) (mm) (%) (blows/ft) (psf) (psf) (psf)Crod[6]Cener [7]Cb[8]Cs[9]CSPT[10](blows/ft)
0 0.0
7.0 -7.0 118 Unit 4 Silty CLAY CL 108.0 SPT 72 15 826 826 389 0.75 1.20 1.00 1.00 1.00 14
10.0 -10.0 120 Unit 3 Silty Sand SM 108.0 SPT 72 21 1186 1186 562 0.80 1.20 1.00 1.00 1.00 20
12.0 -12.0 120 Unit 3 Silty Sand SM 108.0 SPT 72 63 1426 1426 677 0.80 1.20 1.00 1.00 1.00 60
14.0 -14.0 120 Unit 3 Silty Sand SM 108.0 SPT 72 31 1666 1666 792 0.85 1.20 1.00 1.00 1.00 32
16.0 -16.0 120 Unit 3 Silty Sand SM 108.0 SPT 72 20 1906 1906 908 0.85 1.20 1.00 1.00 1.00 20
18.0 -18.0 120 Unit 3 Silty Sand SM 108.0 SPT 72 25 2146 2146 1023 0.85 1.20 1.00 1.00 1.00 26
Notes:
[1]Evaluation is based on: "Idriss and Boulanger (2008), Soil Liquefaction During Earthquakes , EERI Monograph MNO-12"
[2] Boring location known to exist somewhere in Section 32 of the Clive Facility
[3]amax and earthquake magnitude based on parameters presented in the seismis hazard analysis by AMEC 2012
[4] ``
[5]Estimated to result in Cenergy of 0.8 assuming Autohammer
[6]Crod accounts for short rod correction (<1 if rod length < 10 meters) (Table 3, I&B 2008)
[7]Cenergy accounts for rod energy delivered to sampler (Table 3, I&B 2008)
[8]Cb accounts for the effect of the size of the borehole (Table 3, I&B 2008)
[9]s accounts or t e e ect o t e ners n t e samp er a e ,
[10]CSPT is a correction factor to adjust the blow counts recorded with MOD-CAL samplers to equivalent SPT blow count values.
CSPT is assumed to be 1.0 for SPT samples and 0.60 for MOD-CAL samples based on an outside diameter of 3.0 inches
and an inside diameter of 2.4 inches (Burmister, 1948)
[11]m=0.784-0.0768sqrt((N1)60cs)0.264 is iteratively calculated until (N1)60cs converges (Equation 33 and 39, I&B 2008)
[12]CN=(Pa/σ'v)1.7 accounts for effective overburden stress (Equation 33, I&B 2008)
24-Dec-91
Soil Unit USCS
Class Sample Type
Nfield Correction Factors
Page 5 GW-38
Boring: GW-38 (continued from previous page)
Date:
By: Overland Drilling
Fines
Content [11] [12](N1)60[13](N1)60cs[15][16] [17] [18] [19] [20] [21] [22] [25] [27] [28] [29] [30] [31] [32]
%m CN (blows/ft) (blows/ft) rd Cσ KCRRM7.5,'vc CSRM7.5,'vc Δ(N1)60-FC (N1)60CS-Sr FS γlim Fα γmax ΔHi εv Δsi Cum Settle
0.02
100.0 Est 0.399 1.46 20 5.5 25 -0.08 0.01 0.99 0.164 1.100 0.29 0.282 5 25 1.04 0.02
15.0 Est 0.375 1.24 25 3.3 28 -0.14 0.02 0.98 0.188 1.100 0.40 0.278 1 26 1.43
15.0 Est 0.264 1.11 67 3.3 70 -0.17 0.02 0.97 0.300 1.100 50.00 0.275 1 68 181.73
15.0 Est 0.315 1.08 34 3.3 37 -0.22 0.02 0.96 0.300 1.100 1.91 0.273 1 35 7.02
15.0 Est 0.404 1.04 21 3.3 25 -0.26 0.03 0.96 0.160 1.100 0.28 0.270 1 22 1.03 9.4% 0.26 3.2% 2.0 0.8% 0.02 -0.02
15.0 Est 0.373 0.99 25 3.3 29 -0.30 0.03 0.95 0.190 1.100 0.41 0.268 1 26 1.53
Settlement 0.02 ft
[13](N1)60=N60*CN is the overburden corrected penetration resistance (Equation 31, I&B 2008)Settlement 0.2 in
[14](N1)60=exp[1.63+(9.7/(FC+0.1))-(15.7/(FC+0.01))2] represents the change in (N1)60 with fines content (Equation 76, I&B 2008)
[15](N1)60cs=(N1)60 + (N1)60 is the equivalent clean-sand SPT penetration resistance (Equation 75, I&B 2008)
[16](z) = -1.012-1.126sin((z/11.73)+5.133) in which z is depth in meters (Equation 23, I&B 2008)
[17](z) = 0.106+0.118sin((z/11.28)+5.142) in which z is depth in meters (Equation 24, I&B 2008)
[18]rd=exp[α(z)+β(z)M] is shear stress reduction coefficient (Equation 22, I&B 2008)
[19]Cσ=1/(18.9-2.55sqrt[(N1)60cs]0.3 is the coefficient for K (Equation 56, I&B 2008)
[20]K = 1-Cσln(vo'/Pa)1.1 is the overburden correction factor (Equation 54, I&B 2008)
[21]M7.5,'vc s t e er ve corre at on etween an correcte penetrat on res stance quat on ,
[22]CSRM7.5,'vc=0.65(amax/g)(v/v')rd(1/MSF)(1/Kσ) is the equivalent CSR for the reference values of M=7.5 and 'vc=1 atm (Equation 69, I&B 2008)
[23] NL = non-liquefiable; L = potentially liquefiable
[24] Groundwater assumed to be at a depth of 170 feet below ground surface during the field investigation (for blow count correction)
[25] Fines content correction for liquefied shear strength from Seed 1987 (Table 4, pg 126, I&B 2008)
[26] MOD-CAL refers to 2.5-inch ID sampler
[27]γlim = 1.859[1.1 - sqrt((N1)60cs/46)]3 > 0 but less than 50% = limiting shear strain (Equation 86, I&B, 2008)
[28]Fα = 0.032 + 0.69sqrt[(N1)60cs] - 0.13(N1)60cs, where (N1)60cs is limited to values > 7 (Equation 93, I&B, 2008)
[29]γmax = min[γlim, 0.35(2-FS)((1-Fα)/(FS-Fα)] for 2 > FS > Fα; if FS < Fα, γmax = γlim (Equations 91 & 92, I&B, 2008)
[30]ΔHi = Layer thickness (ft)
[31]εv = 1.5exp(-0.369sqrt[(N1)60cs] x [min(0.08, γmax )] = post liquefaction volumetric strain (Equation 96, I&B, 2008)
[32]ΔSi = (Δhi)(εv)
Δ(N1)60[14]
24-Dec-91
Fines
Content
Method
Page 6 GW-38