Laserfiche WebLink
-6- <br />claystone possesses a moderate swell potential. Hard shale bedrock was <br />encountered below an approximate 35-foot depth and exhibits very high <br />supportive capacity as wall as good competency. The proposed excavation ~ <br />c <br />a <br />depth will stop at approximately the upper contact level of this~materlal. <br />A free water level was not encountered at time of drilling but did <br />develop at approximate Elevation 6402 feet several days following drilling. <br />q <br />1 <br />This level occurs within the claystone bedrock, which could possibly i <br />rise to the top of bedrock during time of spring runoff. j <br />3 <br />Crusher: Subsoils and underlying bedrock encountered at the <br />crusher area are similar to those at the truck dump. However, as dis- <br />closed by the Logs of Test Holes, Fig. 3, the subsurface stratification <br />• y across the crusher site Is quite variable. Depth to bedrock was encoun- <br />tered at 6 to 14 feet and varies approximately 11 feet to elevation from <br />Test Holes 3 to 6. Results of swell-consolidation tests, presented on <br />Figs. 13 and 15, Indicate that the overburden soils possess low to <br />moderate swell potential. Approximate maximum swelling prnssures of ~ <br />t <br />- .10.000 psf'were indicated. <br />Seepage Into the test holes at time of drilling was very slow; <br />however, a free water level near thn top of bedrock developed several <br />days following drilling. <br />Stockpile: The stockpile and reclaim substructure are located In <br />the area of deepest soil cover encountered. Near-surface clay soils <br />extend to approximate 7- to 9-foot depths, approximately 4 to 7 feet <br />~: <br />below proposed final surface grade elevation of 6402.0 feet: Three to <br />. 4 feat of clayey sand and gravel was then encountered overlying the <br /> <br />