Laserfiche WebLink
Newmont Mining Corporation <br /> Record of Construction Report ■ <br /> VLF2 Recertification Project <br /> Subgrade and Geomembrane 9650'—9750'Elevations <br /> NewFields Project No.475.0106.026 <br /> July 3,2018 <br /> 5.1.4. Geomembrane Extrusion Seaming <br /> Around the perimeter of the recertification area, the deployed geomembrane was tied-into the <br /> previously placed geomembrane using fusion welding as the primary tie-in method. The tie-in <br /> was welded using extrusion welding methods if fusion welding was not feasible. Prior to extrusion <br /> seaming activities, trial welds were performed for each welding machine and welding technician <br /> combination. The extrusion trial seam logs are presented in Appendix E.3. As extrusion seaming <br /> was performed proper techniques were verified, including welding angle, grinding, and <br /> weld/welding rod cleanliness. The CQA Monitor logged the welding machine and welding <br /> technician combination, the length of the seam, the direction the seam was welded, time of <br /> seaming,the pre-heat temperature,and the welding temperature. Destructive test samples were <br /> marked during extrusion seaming and testing is discussed further in Section 5.1.5. All extrusion <br /> welded seams were vacuum tested and is discussed further in Section 5.1.7.The Geomembrane <br /> Extrusion Welding Summary is presented in Appendix E.S. <br /> 5.1.5. Geomembrane Destructive Testing <br /> During welding activities destructive test samples were marked for every 500 linear feet of seam <br /> for each welding type and each welding machine/welding technician combination.A 24-inch long <br /> by 12-inch wide sample was cut from the seam centered on the seam lengthwise. The sample <br /> was then cut in two halves. One half was archived by the CQA Monitor to be tested later, if <br /> necessary.Ten 1-inch coupons were then cut from the remaining sample half. Five coupons were <br /> tested for shear strength and five coupons were tested for peel strength using a tensiometer. <br /> The different failure types and test codes for fusion and extrusion destructive testing are <br /> presented on Figures 1 and 2, respectively.All destructive testing was performed by Comanco in <br /> the presence of the CQA Monitor. One destructive test failed (RCDF-9) within the VLF2 <br /> Recertification Subgrade and Geomembrane between 9650' and 9750' elevations project. The <br /> failing area was tracked, identified, repaired, and re-tested within the requirements of the <br /> Technical Specifications. Fusion and Extrusion Destructive Testing Summaries are presented in <br /> Appendix E.6 and Appendix E.7, respectively, and the tensiometer certifications are presented in <br /> Appendix G. <br /> 5.1.6. Geomembrane Pressure Testing <br /> Pressure testing was performed to ensure all fusion welded seams had continuity throughout <br /> their entire length. The ends of the seam were sealed and the air channel in the seam was <br /> pressurized using a small air compressor to a minimum of 30 pounds per square inch (psi), for a <br /> minimum of five minutes. A pressure gauge and needle were used to monitor the air pressure in <br /> the seam. If the pressure dropped less than 3 psi,the opposite end of the seam from the pressure <br /> gauge was cut. If the needle dropped, continuity was confirmed throughout entire seam length <br /> Page 10 <br />