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t <br />' San Luu Project - Phase n Raise 1 Expansion Construction Status Rcport <br />Larger cobble sized materials are also occasionally present in the Type 2 material obtained from <br />the borrow source. These cobbles aze removed during the Owners visual inspection of the liner <br />cover as it is pushed out over the liner and placed on the surface of the cover material. <br />The Engineer has requested samples at siz-inch depth intervals through the placed cover material <br />' down to the VLDPE liner at random locations for gradation testing to verify that significant <br />layering or material segregation is not occurring during placement. These test indicate a general <br />' lack of layering and relatively consistent material over the full depth placed. Initial Type 2 <br />material placement near the south abutment of the raise, Acre 1, proved difficult on the steep <br />slopes and required pushing numerous loads of material up the slope. This resulted in poor <br />' blending and some layering as evidenced by the test results. This azea will be investigated in <br />more detail to determine the extent and degree of layering that occurred and the proper means <br />' to eliminate the layering if that proves to be required. <br />Field permeability tests in the Type 2 material in azeas of high equipment traffic were requested <br />by the Engineer to demonstrate the affect of excessive trafficking to the Contractor. These tests <br />indicate that areas receiving heary equipment traffic exhibit permeabilities which are <br />approximately 2z lower than those areas receiving minimal traffic. Areas which have received <br />minimal traffic have exhibited field permeability values which range from 1.7 to 3.6 z 10~ <br />' cm(sec and averaged 2.8 x 10~ cm/sec (6 tests). Laboratory permeability testing of Type 2 <br />material prepared at the field density has been initiated. Preliminary results of these tests <br />' indicate permeabilities of 4.7 x lo-s and 2.5 z 10~ cm/sec. The difference in fie11d to laboratory <br />permeability testing is interpreted to in part be due to the equipment used for the insitu tests. <br />This equipment is the BAT insitu permeability apparatus manufactured by BAT Envitech AB of <br />' Danderyd, Sweden, which is ideally suited to measurement of the lower permeabilities of the <br />liner at the site. At higher permeabilities some error exists for this type of egtipment due to <br />' incomplete saturation of the material surrounding the test probe. A higher degree of confidence <br />is therefore given to the laboratory permeability values. Comparison of the BAT field <br />' permeability test results with laboratory permeability values for the clay liner layer during Pfiase <br />I construction indicated excellent agreement for this material. This information will be made <br />available upon completion of the tests. <br />' A summary of the results of all QA/QC testing for this material is presented in Appendrz D.2. <br />' October, 1993 12 SRK Project No. 14725 <br />