Geotechnical Manual - TxDOT
Dec 1, 2012 . always base the depth of boring on the final grade lines. Cantilever drilled shaft .. If free water is present, describe the soil as wet or water-bearing. Color . Sandstone, chert, schist, granite, gneiss, some .. tion factor of 0.7 to allowable skin friction values derived from Figure 5-1 or from laboratory testing.