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HomeMy WebLinkAboutDSHW-2024-004140Subgrade Construction QC/QA Plan Introduction This document (Subgrade Construc on Quality Control/Quality Assurance Plan) is intended to generally document standard procedures u lized to ensure a quality installa on. This document complements, and does not replace, applicable site-specific project specifica ons. References: CETCO Bentomat Installa on Guidelines and the 2017 APWA Manual of Standard Specifica ons Sec ons 31 05 13, 31 23 16, and 31 23 26. Subgrade Preparation The subgrade surface to receive geocomposite materials shall be prepared and inspected in accordance with the project specifica ons. Surfaces shall be smooth and free of sharp rocks or debris. Subgrade surfaces consis ng of granular soils or gravels are not acceptable due to their large void frac on and puncture poten al. When the GCL is placed over an earthen subgrade, the subgrade surface must be prepared in accordance with the project specifica ons. The engineer’s approval of the subgrade must be obtained prior to installa on. The finished surface should be firm and unyielding, without abrupt eleva on changes, voids, cracks, ice, or standing water. The subgrade surface must be smooth and free of vegeta on, sharp-edged rocks, stones, s cks, construc on debris, and other foreign ma;er that could contact the GCL. The subgrade should be rolled with a smooth-drum compactor to remove any wheel ruts greater than 1 inch in depth, footprints, or other abrupt grade changes. Furthermore, all protrusions extending more than 0.5 inch (12 mm) from the subgrade surface shall be removed, crushed, or pushed into the surface with a smooth- drumcompactor. The GCL may be installed on a frozen subgrade, but the subgrade soil in the unfrozen state should meet the above requirements. Material When allowed by Engineer, material obtained from Excava ons may be used as fill, provided organic material, rubbish, debris, and other objec onable materials are removed. For op mum soil density use ASTM D2216 and the following industry standards. 1. For A-1 Soils: Method C of ASTM D1557 (Modified Proctor) 2. For All Other Soils: Method C of ASTM D698 (Standard Proctor) Compaction Moisten or dewater backfill material to obtain op mum moisture for compac on. Compact the en re area to 95 percent and eliminate unstable zones. Correct deficient compac on condi ons. Replace or repair materials and damaged facili es. No density determina ons are required on any material containing more than 65 percent material retained on the number 10 sieve or more than 60 percent material retained on the number 4 sieve. In lieu of repor ng densi es in such cases, report the sieve analysis to document the material type. Inspection Prior to implemen ng any of the work in the sec on to be lined with GCL, the Installer shall carefully inspect the prepared subgrade of all other sec ons and verify that all work is complete to the point where the installa on of the sec on may properly commence without adverse impact. If the Installer has any concerns regarding the prepared subgrade, he shall no fy the Project Engineer. Geosynthetic Clay Liner Construction QC/QA Plan Introduction This document (Geosynthe c Clay Liner Construc on Quality Control/Quality Assurance Plan) is intended to generally document standard procedures u lized to verify a quality installa on. This document complements, and does not replace, applicable site-specific project plans and specifica ons. References: CETCO Bentomat Installa on Guidelines. Equipment Requirements CETCO GCLs are delivered in rolls typically 2,600-2,950 lbs (1180-1340 kg). Roll dimensions and weights will vary with the dimensions of the product ordered. It is necessary to support this weight using an appropriate core pipe, as indicated in Table 1. For any installa on, the core pipe must not deflect more than 3 inches (75 mm), as measured from end to midpoint when a full GCL roll is li<ed. Li<ing chains or straps appropriately rated should be used in combina on with a spreader bar made from an I-beam, as shown in Figure 1. The spreader bar ensures that li<ing chains or straps do not chafe against the ends of the GCL roll, allowing it to rotate freely during installa on. Spreader bar and core pipe kits are available through CETCO. A front end loader, backhoe, dozer, or other equipment can be u lized with the spreader bar and core pipe or slings. Alterna vely, a forkli< with a “s nger” a@achment may be used for on-site handling. A forkli< without a s nger a@achment should not be used to li< or handle the GCL rolls. S nger a@achments (Figures 2-4) are specially fabricated to fit various forkli< makes and models. When installing over certain geosynthe c materials, a 4 wheel, all-terrain vehicle (ATV) can be used to deploy the GCL. An ATV can be driven directly on the GCL provided that no sudden stops, starts, or turns are made. Addi onal equipment needed for installa on of CETCO GCLs includes: · U lity knife and spare blades (for cuDng the GCL) · Granular bentonite for end-of-roll GCL seams and for sealing around structures and details · Waterproof tarpaulins (for temporary cover on installed material as well as for stockpiled rolls) · Op onal flat-bladed vise grips (for posi oning the GCL panel by hand) The CETCO EASY ROLLER™ GCL Deployment System is a preferred method of installing geosynthe c clay liners. Use of the EASY ROLLER system eliminates the need for spreader bars and heavy core pipes. Installa on speed and worker safety are also significantly increased. For further details, contact CETCO. Shipping, Unloading, and Storage All lot and roll numbers should be recorded and compared to the packing list. Each roll of GCL should also be visually inspected during unloading to determine if any packaging has been damaged. Damage, whether obvious or suspected, should be recorded and the affected rolls marked. Major damage suspected to have occurred during transit should be reported to the carrier and to CETCO immediately. The nature of the damage should also be indicated on the bill of lading, with specific lot and roll numbers noted. Accumula on of some moisture within roll packaging is normal and does not damage the product. The party directly responsible for unloading the GCL should refer to this manual prior to shipment to ascertain the appropriateness of their unloading equipment and procedures. Unloading and on-site handling of the GCL should be supervised. In most cases, CETCO GCLs are delivered on flatbed trucks. There are three methods of unloading: core pipe and spreader bar, slings, or s nger bar. To unload the rolls from the flat-bed using a core pipe and spreader bar, first insert the core pipe through the core tube. Secure the li<ing chains or straps to each end of the core pipe and to the spreader bar mounted on the li<ing equipment. Hoist the roll straight up and make sure its weight is evenly distributed so that it does not lt or sway when li<ed. All CETCO GCLs are delivered with two 2’x 12’ (50 mm x 3.65 mm) Type V polyester endless slings on each roll. Before li<ing, check the posi on of the slings. Each sling should be ed off in the choke posi on, approximately one third (1/3) from the end of the roll. Hoist the roll straight up so that it does not lt or sway when li<ed. In some cases, GCL rolls will be stacked in three pyramids on flatbed trucks. If slings are not used, rolls will require unloading with a s nger bar and extendible boom fork li<. Spreader bars will not work in this situa on because of the limited access between the stacks of GCL. Three types of s ngers are available from CETCO, a hook mount, fork mount and pin mount (Figures 2-4). To unload, guide the s nger through the core tube before li<ing the GCL roll and removing the truck. An extendable boom fork li< with a s nger bar is required for unloading vans. Rolls in the nose and center of the van should first be carefully pulled toward the door using the slings provided on the rolls. Rolls should be stored at the job site away from high-traffic areas but sufficiently close to the ac ve work area to minimize handling. The designated storage area should be flat, dry, and stable. Moisture protec on of the GCL is provided by its packaging; however, based on expected weather condi ons, an addi onal tarpaulin or plas c sheet may be required for added protec on during prolonged outdoor storage. Rolls should be stacked in a manner that prevents them from sliding or rolling. This can be accomplished by chocking the bo@om layer of rolls. Rolls should be stacked no higher than the height at which they can be safely handled by laborers (typically no higher than four layers of rolls). Rolls should never be stacked on end. Subgrade Preparation Subgrade surfaces consis ng of granular soils or gravels are not acceptable due to their large void frac on and puncture poten al. When the GCL is placed over an earthen subgrade, the subgrade surface must be prepared in accordance with the project specifica ons. The engineer’s approval of the subgrade must be obtained prior to installa on. The finished surface should be firm and unyielding, without abrupt eleva on changes, voids, cracks, ice, or standing water. The subgrade surface must be smooth and free of vegeta on, sharp-edged rocks, stones, s cks, construc on debris, and other foreign ma@er that could contact the GCL. The subgrade should be rolled with a smooth-drum compactor to remove any wheel ruts greater than 1 inch in depth, footprints, or other abrupt grade changes. Furthermore, all protrusions extending more than 0.5 inch (12 mm) from the subgrade surface shall be removed, crushed, or pushed into the surface with a smooth-drum compactor. The GCL may be installed on a frozen subgrade, but the subgrade soil in the unfrozen state should meet the above requirements. Installation GCL rolls should be taken to the work area of the site in their original packaging. The orienta on of the GCL (i.e., which side faces up) may be important if the GCL has two different types of geosynthe cs. Check with the project engineer to determine if there is a preferred installa on orienta on for the GCL. If no specific orienta on is required, allow the roll to unwind from the bo@om rather than pulling from the top (Figure 5A). The arrow s cker on the plas c sleeve indicates the direc on that the GCL will naturally unroll when placed on the ground (Figure 6). Prior to deployment, the packaging should be carefully removed without damaging the GCL. Equipment which could damage the GCL should not be allowed to travel directly on it. Therefore, acceptable installa on may be accomplished whereby the GCL is unrolled in front of backwards-moving equipment (Figure 7). If the installa on equipment causes ruDng of the subgrade, the subgrade must be restored to its originally accepted condi on before placement con nues. If sufficient access is available, GCL may be deployed by suspending the roll at the top of the slope, with a group of laborers pulling the material off of the roll, and down the slope (Figure 8). GCL rolls should not be released on the slope and allowed to unroll freely by gravity. Care must be taken to minimize the extent to which the GCL is dragged across the subgrade to avoid damage to the bo@om surface of the GCL. Care must also be taken when adjus ng BENTOMAT CLT panels to avoid damage to the geotex le surface of one panel of GCL by the textured sheet of another panel of GCL. A temporary geosynthe c subgrade cover commonly known as a slip sheet or rub sheet may be used to reduce fric on damage during placement. The GCL should be placed so that seams are parallel to the direc on of the slope. End-of-panel seams should also be located at least 3 < (1 m) from the toe and crest of slopes steeper than 4H:1V. End-of-roll seams on slopes should be used only if the liner is not expected to be in tension. All GCL panels should lie flat, with no wrinkles or folds, especially at the exposed edges of the panels. When BENTOMAT geosynthe c clay liners with SUPERGROOVE® is reposi oned, it should be gripped inside the SUPERGROOVE by folding the edge. The GCL should not be installed in standing water or during rainy weather. Only as much GCL shall be deployed as can be covered at the end of the working day with soil, geomembrane, or a temporary waterproof tarpaulin. The GCL shall not be le< uncovered overnight. If the GCL is hydrated when no confining stress is present, it may be necessary to remove and replace the hydrated material. CETCO recommends that premature hydra on be evaluated on a case-by-case basis. The project engineer, CQA inspector, and CETCO TR-312 should be consulted for specific guidance if premature hydra on occurs. The type of GCL, dura on of exposure, degree of hydra on, loca on in the liner system, and expected bearing loads should all be considered. In many instances, a needle punch reinforced GCL may not require removal/replacement if the following are true: · The geotex les have not been separated, torn, or otherwise damaged · There is no evidence that the needle punching between the two geotex les has been compromised · The GCL does not leave deep indenta ons when stepped upon · Overlapped seams with bentonite enhancement are intact For the convenience of the installer, hash marks are placed on BENTOMAT goesynthe c clay liners every 5’ (1.5 m) of length. Anchorage If required by the project drawings, the end of the GCL roll should be placed in an anchor trench at the top of a slope. The front edge of the trench should be rounded to eliminate any sharp corners that could cause excessive stress on the GCL. Loose soil should be removed or compacted into the floor of the trench. If a trench is used for anchoring the end of the GCL, soil backfill should be placed in the trench to provide resistance against pullout. The size and shape of the trench, as well as the appropriate backfill procedures should be in accordance with the project drawings and specifica ons. Typical dimensions are shown in Figure 9. The GCL should be placed in the anchor trench such that it covers the en re trench floor but does not extend up the rear trench wall. Sufficient anchorage may alternately be obtained by extending the end of the GCL roll back from the crest of the slope and placing cover soil. The length of this “runout” anchor should be prepared in accordance with project drawings and specifica ons. Seaming GCL seams are constructed by overlapping adjacent panel edges and ends. Care should be taken to ensure that the overlap zone is not contaminated with loose soil or other debris. BENTOMAT 200R, BENTOMAT ST, BENTOMAT DN, and BENTOMAT FLW have SUPERGROOVE® which provides self-seaming capabili es in their longitudinal overlaps, and therefore do not require supplemental bentonite. However, for pond applica ons, supplemental bentonite must be used in longitudinal seams, regardless of the CETCO GCL. Longitudinal seams should be overlapped a minimum of 6 inches (150 mm) for BENTOMAT geosynthe c clay liners. For high-head applica ons (greater than 1 foot or 20.48 cm) involving BENTOMAT CL, BENTOMAT CLT, or BENTOMAT 600 CL, a minimum longitudinal seam overlap of 12 inches (300 mm) and supplemental bentonite is recommended. End-of-panel overlapped seams should be overlapped 24 inches (600 mm) for BENTOMAT geosynthe c clay liners. End-of-panel overlapped seams are constructed such that they are shingled in the direc on of the grade to prevent runoff from entering the overlap zone. End-of-panel seams on slopes are permissible, provided adequate slope stability analysis has been conducted (i.e., the GCL is not expected to be in tension). Bentonite-enhanced seams are required for all BENTOMAT end-of-panel over lapped seams. BENTOMAT end-of-panel, bentonite-enhanced, overlapped seams are constructed first by overlapping the adjacent panels, exposing the underlying panel, and then applying a con nuous bead or fillet of granular sodium bentonite 12” from the edge of the underlying panel (Figure 11). The minimum applica on rate at which the bentonite is applied is one-quarter pound per linear foot (0.4 kg/m). If longitudinal bentonite enhanced seams are required for BENTOMAT 200R, BENTOMAT ST, BENTOMAT DN, or BENTOMAT SDN, they are constructed by overlapping the adjacent panels a minimum 6 inches (150 mm), exposing the underlying edge, and applying a con nuous bead of granular bentonite approximately 3 inches (75 mm) from the edge. For pond applica ons involving BENTOMAT CL or BENTOMAT CLT, longitudinal seams are constructed by overlapping adjacent panels by 12 inches (300 mm), exposing the underlying edge, and applying a con nuous bead of bentonite approximately 6 inches (150 mm) from the edge. The minimum applica on rate for the granular bentonite is one quarter pound per linear foot (0.4 kg/m). Sealing Around Penetrations and Structures CuDng the GCL should be performed using a sharp u lity knife. Frequent blade changes are recommended to avoid irregular tearing of the geotex le components of the GCL during the cuDng process. The GCL should be sealed around penetra ons and structures embedded in the subgrade in accordance with Figures 12 through 14. Granular bentonite shall be used liberally (approximately 0.25 lbs/ln. <. or 0.4 kg/m) to seal the GCL to these structures. When the GCL is placed over a horizontal pipe penetra on, a “notch” should be excavated into the subgrade around the penetra on (Figure 12a). The notch should then be backfilled with granular bentonite. A secondary collar of GCL should be placed around the penetra on, as shown in Figure 12b. It is helpful to first trace an outline of the penetra on on the GCL and then cut a “star” pa@ern in the collar to enhance the collar’s fit to the penetra on. Granular bentonite should be applied between the primary GCL layer and the secondary GCL collar. Ver cal penetra ons are prepared by notching into the subgrade as shown in Figure 13a. The penetra on can be completed with two separate pieces of GCL as shown in Figure 13b. Alterna vely, a secondary collar can be placed as shown in Figure 12a or 12b. When the GCL is terminated at a structure or wall that is embedded into the subgrade on the floor of the containment area, the subgrade should be notched. The notch is filled with granular bentonite; the GCL should be placed over the notch and up against the structure (Figure 14). Connec on to the structure can be accomplished by placement of soil or stone backfill in this area. When structures or walls are at the top of a slope, addi onal detailing may be required. Damage Repair If the GCL is damaged (torn, punctured, perforated, etc.) during installa on, it may be possible to repair it by cuDng a patch to fit over the damaged area (Figure 15). The patch should be cut to size such that a minimum overlap of 12 inches (300 mm) is achieved around all parts of the damaged area. Granular bentonite should be applied around the damaged area prior to placement of the patch. It may be necessary to use an adhesive such as wood glue to affix the patch in place so that it is not displaced during cover placement. Smaller patches may be tucked under the damaged area to prevent patch movement. Cover Placement The final thickness of soil cover on the GCL varies with the applica on. A minimum cover layer must be at least 2 foot thick to provide confining stress to the GCL, eliminate the poten al for seam separa on and prevent damage by equipment, erosion, etc. Cover soils should be free of angular stones or other foreign ma@er that could damage the GCL. Cover soils should be approved by the engineer with respect to par cle size, uniformity, and chemical compa bility. Consult CETCO if cover soils have high concentra ons of calcium (e.g. limestone, dolomite, gypsum, seashell fragments). Recommended cover soils should have a par cle size distribu on ranging between fines and 1 inch (25 mm), unless a cushioning geotex le is specified. Soil cover shall be placed over the GCL using construc on equipment that minimizes stresses on the GCL. A minimum thickness of 2 feet of cover soil should be maintained between the equipment res/tracks and the GCL at all mes during the covering process. In high-traffic areas such as on roadways, a minimum thickness of 3 feet is required. Soil cover should be placed in a manner that prevents the soil from entering the GCL overlap zones. Soil cover should be pushed up on slopes, not down slopes, to minimize tensile forces on the GCL. When a textured geomembrane is installed over the GCL, a temporary geosynthe c covering known as a slip sheet or rub sheet should be used to minimize fric on during placement and to allow the textured geomembranes to be more easily moved into its final posi on. Cyclical weDng and drying of GCL covered only with geomembrane can cause overlap separa on. Soil cover should be placed promptly whenever possible. Geomembranes should be covered with a white geotex le and/or opera ons layer without delay to minimize the intensity of wet-dry cycling. If there is the poten al for unconfined cyclic weDng and drying over an extended period of me, the longitudinal seam overlaps should be increased based on the project engineer’s recommenda on. To avoid seam separa on, the GCL should not be put in excessive tension by the weight or movement of textured geomembrane on steep slopes. If there is the poten al for unconfined geomembrane expansion and contrac on over an extended period of me, the longitudinal seam overlaps should be increased based upon the project engineer’s recommenda on. Hydration Hydra on is usually accomplished by natural rainfall and/or absorp on of moisture from soil. However, in cases where the containment of non-aqueous liquid is required, it may be necessary to hydrate the covered GCL with water prior to use. If manual hydra on is necessary, water can be introduced by flooding the covered lined area or using a sprinkler system. If flooding, care must be taken to diffuse the energy of the water discharge so that the cover material is not displaced. If the GCL is hydrated when no confining stress is present, it may be necessary to remove and replace the hydrated material. In many instances a needle punch reinforced GCL may not require removal/replacement if the following are true: · The geotex les have not been separated, torn or otherwise damaged · There is no evidence that the needle punching between the two geotex les has been compromised · The GCL does not leave deep indenta ons when stepped upon · Any overlapped seams with bentonite enhancement are intact HDPE Liner Construction QC/QA Plan Introduction This document (HDPE Liner Construc on Quality Control/Quality Assurance Plan) is intended to generally document standard procedures u lized to verify a quality installa on. This document complements, and does not replace, applicable site-specific project plans and specifica ons. References: Project Manual Sec on 33 50 10S 60 Mil HDPE Liner. Geomembrane Materials New, uniform, unmodified high density polyethylene sheet containing no plas cizer, filters, reclaimed polymers or extenders and the product of only one manufacturer. Either black or white smooth surface on 1 side, textured black surface on other side. 1. White surface and black layer must be integral to the geomembrane. 2. No gaps in the white layer. 3. White layer must not delaminate during physical tes ng. 4. White layer thickness is Contractor’s op on. 5. White material must be made with the same resin, and stabilized with a non-carbon black ultra- violet stabilizer to meet warranty condi ons. 6. Edge Trim: 2 maximum. 7. Heat Stabilizers, An oxidants and Processing Aids in Resins: < 0.5. 8. No tears or defects. 9. Meet the requirements of Table 1 of Sec on 33 50 10S of the Project Manual. Extrudate formulated from the same high density polyethylene resin as the geomembrane. Sealant caulking, clamps, tape, and rubber pads per the geomembrane manufacturer’s recommenda ons. Perform the quality control tests at the frequencies shown in Table 1 of Sec on 33 50 10S of the Project Manual. Supply copies of tes ng to the Engineer. Material Delivery Approved geosynthe c materials shall be delivered to the project site, unloaded and stored in a prepared area protected from damage by puncture, ponding water, airborne contaminates or traffic. All materials shall be properly labeled and cross-referenced with packing slips. Any visible damage to roll goods delivered to the project site shall be documented. Rolls with significant damage shall be marked and stored separately on site for further evalua on. A complete material inventory shall be completed and kept up to date to ensure that sufficient quan ty of the required materials exists on site to fulfill the project requirements. Site Preparation The subgrade surface to receive geosynthe c materials shall be prepared and inspected in accordance with the project specifica ons. Surfaces shall be smooth and free of sharp rocks or debris. The subgrade surface shall be firm and unyielding, capable of providing a founda on for geosynthe c lining that does not rut when trafficked over by a forkli@ loaded with a roll of geosynthe c material. Instruct workers about protec ng geomembrane such as handling the material in high winds; handling of equipment; discard of u lity knife blades; cleanup of membrane cuCngs; shoes of all personnel walking on the membrane; smoking; ea ng or drinking; and placing heated equipment on the membrane. Roll surface of low permeability layer smooth and level. Round edges and grade changes to 12 inch radius minimum. Fill voids and cracks. Make surface free of stones or protrusions greater than 0.25-inch diameter, and free of organic and other deleterious material. Limit ruts on surface to a maximum depth of 1 inch. Repair damaged surface prior to installa on of geomembrane. Installation Deploy each panel in accordance with panel layout drawings and manufacturer’s recommenda ons. Provide sufficient material to allow for geomembrane expansion and contrac on. Install panels so overlapping panel is upgrade of the underlying panel. Do not fold the geomembrane. Geosynthe c materials shall be deployed using a spreader bar or carpet pole assembly aFached to a forkli@ or skit steer assisted by low pressure equipment. In general, panels will be deployed in a manner that minimizes risk of in-place damage and parallel to the line of maximum slope. Each panel deployed will be assigned a unique number that will be used to correlate specific roll data to the area of the project in which the roll was u lized. Adequate temporary loading (sandbags) shall be placed on deployed panels to prevent upli@ from wind. Personnel and equipment shall not damage geosynthe c materials during transporta on, handling, or deployment. Geosynthe c placement shall not proceed during precipita on or excess wind condi ons. Seaming A. General: 1. On slopes, seam perpendicular to the line of the slope (i.e. down and not across slope) to at least 6-feet away from the crest or toe of the slope. 2. On module floor, orient seams perpendicular to slope. 3. Minimize number of seams in corners, odd-shaped geometric loca ons, and outside corners. 4. Follow seam coding system. 5. Test Seam: Make test seams to verify that adequate condi ons exist for field searing to proceed. Produce a test seam at the beginning of each shi@ to determine the peel and tensile strength of the seam. Engineer may require a sample field seam be made at any me during seaming produc on to verify equipment. 6. Searing suspensions: If seaming opera on has been suspended for more than 1/2 hour or if the seaming equipment breaks down, produce a test seam prior to resuming of seaming opera ons. 7. Do not build in wrinkles during seaming. B. Qualifica on (Start-Up) Seaming: 1. Seaming samples shall be made for the purpose of qualifying each welding apparatus, welding technician and material type at a minimum of one every four hours. All coupons shall exceed the specified strength requirements before proceeding to produc on seaming. Quality Control must approve trial welds before any welding can be performed. 2. Should a start-up sample fail to meet the strength requirements of the specifica ons, the welding apparatus and welding technician shall not be accepted and shall not be used in produc on seaming un l the deficiencies have been remedied and a successful start-up sample is achieved. C. Produc on Seaming: 1. Personnel u lized in produc on seaming shall be experienced and properly trained. Each welding technician will qualify daily demonstra ng successful start-up seaming that must be approved by Quality Control. 2. Approved methods for field produc on seaming are Fusion or Extrusion. D. Fusion Welding: 1. Geomembrane seams shall have a finished overlap as called out in the specifica ons. Excess overlap shall be trimmed prior to welding. 2. Seam areas shall be wiped clean and inspected to verify that the area is free from moisture and contaminants. E. Extrusion Welding: 1. Geomembrane seams shall have a finished overlap as called out in the specifica ons. 2. Seam areas shall be wiped clean and inspected to verify that the area is free from moisture and contaminants. 3. Seam areas shall be temporarily tack welded together, u lizing a handheld air welder, to hold the patch in place prior to prepara on and extrusion welding. Field Quality Control and Inspection A. Geomembrane Tes ng Equipment: 1. Field Tensiometer: Accompanied by evidence of calibra on, used for on-site shear and peel tes ng of geomembrane seams. 2. Punch Press: Capable of cuCng specimens in accordance with ASTM D 4437. 3. Vacuum Box: Capable of inducing and holding 10 inches of mercury vacuum. 4. Other Tes ng Equipment: As needed by Contractor. B. Observa ons: Visually inspect the geomembrane sheets, seams, anchors, seals, and repairs for defects. Test each seam and repair using a vacuum box or air channel pressure. Perform tests in Engineer’s presence. 1. Fillet Weld, Extrusion Lap Weld, or Single Hot-Wedge Fusion Lap Weld: Use a vacuum box at 4 to 8 inches of mercury. 2. Double Hot-Wedge Seam Weld: Use the following air channel pressure test. a. Pump air into the air channel between the welds to 35 psi and hold for 5 minutes + 1 minute. b. At the end of the period, de-pressurize the seam by placing needle hole in the air space between the welds at the opposite end of the seam and observe the gage. c. At the end of 5 minutes if the seam maintains at least 30 psi during the test and the pressure drops within 30 seconds of de-pressuriza on, the seam is acceptable. d. If the pressure drops below 30 psi during test period, repair needle holes and retest the seam by the same procedure or perform a vacuum box test along the en re length of the seam. e. If the second air pressure test fails, perform a vacuum box test along the en re length of the seam. If no bubbles appear in the vacuum box, the lower weld will be considered defec ve and the upper seam is acceptable. if any bubbles appear in the vacuum box, each defec ve area shall be repaired by extrusion welding and tested again by vacuum box. f. Op on: As an op on to the vacuum box, apply a soap solu on to the exposed seam edge while maintaining the required air channel pressure test. If bubbles appear, mark and extrusion weld the defec ve area. If no bubbles appear and the test pressure cannot be maintained, the leak is judged to be in the boFom or second seam, and the length of the seam tested may be cap stripped. Repair the needle holes. 3. For Seams Where it will be Imprac cable to Perform a Vacuum Test: Insert copper wire for spark test, prior to welding. Place copper wire in the extrudate of the weld and at the edge of the top sheet. C. Seam Tes ng: Perform the tests and meet the quality control criteria of Table 2 in Sec on 33 50 10S of the Project Manual. All 5 shear and 5 peel tests must pass. If 1 does not and is an end sample (bone), remove 1 bone from each end of the sample. If field tensiometer shows a pass the Engineer may deem the seam passing. If the bone fails, proceed with repairs. D. Repairs: Correct the tested field seam as follows. 1. 1. Rerun the field weld test using a new sample. 2. 2. If that second test passes, the Engineer may assume an error was made in the first test 3. and accept the field seam. 4. 3. If that second test fails, either cap the field seam between any two previous passed 5. seam test loca ons that include the failed seam or take another sample on each side of 6. the failed seam loca on (10-feet minimum), and test both. 7. 4. If both pass, cap the field seam between the two loca ons. 8. 5. If either fails, repeat the process of taking samples for test. E. Acceptance of installed geomembrane shall not occur un l adequacy of field seams and repairs, including associated control tes ng is complete. Each field seam is bounded by 2 passes test loca ons. Geonet Construction QC/QA Plan Introduction This document (Geonet Construc on Quality Control/Quality Assurance Plan) is intended to generally document standard procedures u lized to ensure a quality installa on. This document complements, and does not replace, applicable site-specific project plans and specifica ons. References: Project Manual Sec on 31 05 20S Geonet Drainage Layer. Qualifications The Manufacturer shall have manufactured a minimum of 10,000,000 square feet of polyethylene geonet material during the last year. The Installer shall have installed a minimum of 1,000,000 square feet of geonet during the 5 last years. The Installer shall have worked in a similar capacity on at least 5 projects similar in complexity to the project described in the contract documents, and with at least 100,000 square feet of geonet installa on on each project. The Installa on Supervisor shall have worked in a similar capacity on projects similar in size and complexity to the project described in the Contract Documents. Material Labeling, Deliver, Storage and Handling Labeling – Each roll of geomembrane delivered to the site shall be labeled by the manufacturer. The label will iden fy: 1. Manufacturer’s Name 2. Product Iden fica on 3. Length 4. Width 5. Roll Number Delivery – Rolls of geonet will be prepared to ship by appropriate means to prevent damage to the material and to facilitate off-loading. Storage – The on-site storage loca on of the geonet, provided by the Contractor to protect the geonet from abrasions, excessive dirt and moisture shall have the following characteris cs: 1. Level (no wooden pallets) 2. Smooth 3. Protected from the= and vandalism 4. Adjacent to the area being lined Handling – Materials are to be handled so as to prevent damage. 1. The Contractor and Installer shall handle all geonet in such a manner as to ensure it is not damaged in any way. 2. The Installer shall take any necessary precau ons to prevent damage to the underlying layers during placement of the geonet. Approved geosynthe c materials shall be delivered to the project site, unloaded and stored in a prepared secure area protected from damage by: puncture, ponding water, airborne contaminates or traffic. All materials shall be properly labeled and cross-referenced with packing slips and the project approved roll list. Any visible damage to roll goods delivered to the project site shall be documented. Rolls with significant damage shall be marked and stored separately on site for further evalua on by the ECA Superintendent. A complete material inventory shall be completed and kept up to date to veri=y that sufficient quan ty of the required materials exists on site to fulfill the project requirements. Geocomposite rolls should be li=ed off the ground when moving. Dragging of geocomposite rolls against ground surface is not recommended. Opera on of heavy equipment directly on the geocomposite should be avoided. Site Preparation The subgrade surface to receive geocomposite materials shall be prepared and inspected in accordance with the project specifica ons. Surfaces shall be smooth and free of sharp rocks or debris. Installation The geonet roll should be installed in the direc on of the slope and in the intended direc on of fow unless otherwise specified by the Engineer. If the project contains long, steep slopes, special care should be taken so that only full-length rolls are used at the top of the slope. In the presence of wind, all geonets shall be weighted down with sandbags or the equivalent. Such sandbags shall be used during placement and remain un l replaced with cover material. If the project includes an anchor trench at the top of the slopes, the geonet shall be properly anchored to resist sliding. Anchor trench compac ng equipment shall not come into direct contact with the geonet. Any rips, tears, or damaged areas on the deployed geonet shall be removed and patched. The patch shall be secured to the original geonet by tying every 6 inches with the approved tying devices. If the area to be repaired is more than 50 percent of the width of the panel, the damaged area shall be cut out and the two por ons of the geonet shall be joined. In applying fill material, no equipment can drive directly across the geonet. The specified fill material shall be placed and spread u lizing vehicles with a low ground pressure. The cover soil shall be placed in the geonet in a manner that prevents damage to the geonet. Placement of the cover soil shall proceed immediately following the placement and inspec on of the geonet. Each component of the geonet will be secured to the like component at overlaps. Adjacent edges along the length of the geonet roll shall be overlapped a minimum of 6” or as recommended by the engineer. The overlapped edges shall be joined by tying the geonet structure with cable es. These es shall be spaced every 5 feet along the roll length. Adjoining rolls across the roll width should be shingled down in the direc on of the slope and joined together with cable es spaced every foot along the roll width. Inspection Prior to implemen ng any of the work in the sec on to be lined, the Installer shall carefully inspect the installed work of all other sec ons and verify that all work is complete to the point where the installa on of the sec on may properly commence without adverse impact. Prior to covering the deployed geonet, each roll shall be inspected for damage resul ng from construc on. If the Installer has any concerns regarding the installed work of other sec ons, he shall no fy the Project Engineer. Protective Soil Cover Construction QC/QA Plan Introduction This document (Protec ve Soil Cover Construc on Quality Control/Quality Assurance Plan) is intended to generally document standard procedures u lized to verify a quality installa on. This document complements, and does not replace, applicable site-specific project specifica ons. References: CETCO Bentomat Installa on Guidelines and the 2017 APWA Manual of Standard Specifica ons Sec on 31 23 16. Material Recommended cover soils should have a par cle size distribu on ranging between fines and 1 inch (25 mm), unless a cushioning geotex le is specified. Placement The final thickness of soil cover on the GCL varies with the applica on. A minimum cover layer must be at least 1 foot (300 mm) thick to provide confining stress to the GCL, eliminate the poten al for seam separa on and prevent damage by equipment, erosion, etc. Cover soils should be free of angular stones or other foreign ma;er that could damage the GCL. Cover soils should be approved by the engineer with respect to par cle size, uniformity, and chemical compa bility. Consult CETCO if cover soils have high concentra ons of calcium (e.g. limestone, dolomite, gypsum, seashell fragments). Soil cover shall be placed over the GCL using construc on equipment that minimizes stresses on the GCL. A minimum thickness of 2 foot of cover soil should be maintained between the equipment res/tracks and the GCL at all mes during the covering process. In high-traffic areas such as on roadways, a minimum thickness of 3 feet is required. Soil cover should be placed in a manner that prevents the soil from entering the GCL overlap zones. Soil cover should be pushed up on slopes, not down slopes, to minimize tensile forces on the GCL. When a textured geomembrane is installed over the GCL, a temporary geosynthe c covering known as a slip sheet or rub sheet should be used to minimize fric on during placement and to allow the textured geomembranes to be more easily moved into its final posi on. Cyclical we=ng and drying of GCL covered only with geomembrane can cause overlap separa on. Soil cover should be placed promptly whenever possible. Geomembranes should be covered with a white geotex le and/or opera ons layer without delay to minimize the intensity of wet-dry cycling. If there is the poten al for unconfined cyclic we=ng and drying over an extended period of me, the longitudinal seam overlaps should be increased based on the project engineer’s recommenda on. To avoid seam separa on, the GCL should not be put in excessive tension by the weight or movement of textured geomembrane on steep slopes. If there is the poten al for unconfined geomembrane expansion and contrac on over an extended period of me, the longitudinal seam overlaps should be increased based upon the project engineer’s recommenda on.