Laserfiche WebLink
3.4 Field Implementation <br /> Soil descriptions will be recorded on soil boring logs. When logging a soil sample <br /> collected where more than one soil type is present, describe each one separately, using <br /> additional line(s) on the boring log form. Start the description from the top of the split <br /> spoon, and log each change in stratigraphy in sequence to the bottom of the spoon. <br /> Provide an interval or length in feet(ft)(for example, 0-0.5 ft.:)at the beginning of each <br /> separate sequence description, followed by a colon. <br /> The general description of a soil sample should be in the following order: <br /> • USCS soil name; <br /> • Color; <br /> • Moisture content; <br /> • Grain size and percentage with major constituent capitalized, <br /> • Plasticity; <br /> • Consistency/density; <br /> • Geologic modifiers or classifications; and <br /> • Other description(odor, dry strength, mineral content). <br /> Example: SP: Tan, wet, medium SAND (75%), fine sand (10%), coarse sand (5%), silt <br /> (5%), loose, stratified(Alluvium). <br /> 3.4.1 USCS Classification <br /> The USCS classification is based on the grain size distribution of the sample as <br /> summarized in Section 4.4.4, the grading of materials, and the plasticity as summarized <br /> in Section 4.4.5. Consult the soil classification sheet (Appendix A) for USCS symbols <br /> and guidelines. Symbols include GW,GP,GM,GC, SW, SP, SM, SC,ML,CL,OL,CH, <br /> MH, OH, and PT. <br /> The first letter of the USCS classification indicates the dominant grain size. G stands for <br /> gravel, S stands for sand,M stands for silt,C stands for clay,O stands for organic and PT <br /> stands for peat. <br /> The second symbol indicates the grain size distribution or plasticity. W stands for well <br /> graded (or poorly sorted), P stands for poorly graded (or well sorted). Grading is an <br /> 7 <br />