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Uniaxial Compressive Streneth: Unconfined-compressive strength testing was conducted on relatively • <br />undisturbed samples of the overburden materials and bedrock. Each sample was prepared by cutting <br />the end of the specimen parallel to each other and at right angle to the longitudinal axis of the sample. <br />Load was applied continuously and without shock to produce a constant rate of deformation during the <br />test was recorded. Results of the uniaxial compressive strength testing are summazizecl in Table 1. <br />The results were highly variable and ranged from 2750 psf to 73,500 psf. The lowest value was for the <br />sandstone and basically not representative of this type of formation because of the granular <br />characteristic. <br />Swell-Consolidation Tests: Swell-consolidation tests were conducted on samples of sails and bedrock <br />Crom the site in order to determine their compressibility of swell characteristics under loading and <br />saturation. Each sample was prepared and placed in an odometer ring between porous discs. An <br />initial seating load, which was 1000 psf, was placed on the sample. The sample was then saturated with <br />water and the percent change in sample height was measured with a dial gauge. Samples which swelled <br />subsequent [o saturation were loaded incrementally until returned to their original height; the sample <br />height was monitored until deformation practically ceased under each load increment. <br />The wnsolidation test procedures described are similar to ASTM method D-2435. Results of the • <br />consolidation tests are plotted as a curve of the final strain at each increment of pressure against the <br />log of the accumulated pressure. Swell-consolidation test results are presented on Figures 5 to 8. <br />SUBSURFACE CONDITIONS <br />The subsurface conditions encountered near the proposed dam are variable and generally consist of a <br />layer of topsoil overlying interbedded layers of sand, clay and sand/clay overlying competent sandstone <br />bedrock at the proposed dam area to the maximum depth investigated, 55 feet. <br />The overburden sand encountered in the test holes was clean to silty, fine to medium grained with <br />sandstone fragments, non plastic, medium dense to dense, dry to moist and tan to light brown. The <br />interbedded layers of very sandy clays and very clayey sands encountered, fine to medium grained with <br />sandstone fragments, low to medium plastic, loose to very dense, moist to wet and light brown to dark <br />brown. The clay encountered in the test holes was slightly to very sandy with occasional bedrock <br />fragments, low to medium plastic, medium to very stiff to hard, moist to wet and brown to black to <br />grey. <br />• <br />lob No. 91-562 Cround [nginecring Consultants, Inc. 1'agc 4 <br />