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Soil Classification Standard Operating Procedure <br /> SWE-FSOP-201;Revision 0 Ahtna Southwest Environmental Operations <br /> 1.4 Definitions <br /> gINT: Geotechnical and geoenvironmental software that manages borehole logs, well logs, cone <br /> penetration test(CPT), and geophysical logs. <br /> 2.0 Relevant Documents <br /> This SOP is intended to be used in conjunction with the following documents as applicable: <br /> • SWE-FSOP-001, Field Documentation <br /> • SWE-FSOP-002, Field Sample Management <br /> • SWE-FSOP-405, Soil Sampling <br /> 3.0 Basic Equipment List <br /> • A bound, waterproof field logbook (FLB; e.g., Rite in the Rain TM or similar) with pre-numbered <br /> consecutive pages for field documentation <br /> • Waterproof, indelible pens/markers in black or blue ink <br /> • Borehole log forms <br /> • Color chart (MunsellT"^ or equivalent) <br /> • Field charts of grain-size/grain percent examples <br /> • Hand lens <br /> • Compass <br /> • Pocket knife <br /> • Dilute hydrochloric acid in small dispenser/dropper bottle (if calcareous materials anticipated) <br /> • Squirt bottle with water <br /> 4.0 Procedures <br /> 4.1 Description of Physical Properties <br /> The following will be used as a guideline for logging lithology from surface and subsurface activities (i.e., <br /> potholing, borehole drilling, trenching, etc.). The Unified Soil Classification System (USCS) recognizes 15 <br /> soil groups and uses names and letter symbols to distinguish between these groups.The USCS groups are <br /> outlined in Figure 1 and Figure 2 with some modifications from ASTM-D2488 Unified Soil Classification <br /> System. <br /> 4.1.1 Soil Descriptions <br /> Figure 1 and Figure 2 summarize USCS classifications and designations to use when logging samples. The <br /> coarse-grained soils are subdivided into gravels (G) and sands (S). Both the gravel and sand groups are <br /> divided into four secondary groups. Fine-grained soils are subdivided into silts (M) and clays (C). Soils are <br /> also classified according to their plasticity and grading. Plastic soils are able to change shape under the <br /> influence of applied stress and to retain the shape once the stress is removed. Soils are referred to either <br /> low (L) or high (H) plasticity. The grading of a soil sample refers to the particle size distribution of the <br /> sample. A well-graded (W) sand or gravel has a wide range of particle sizes and substantial amounts of <br /> Page 5 of 11 <br />