Unified Soil Classification System group symbol. For example, GW-GM corresponds to "well-graded gravel "with silt"." If the soil has more than 15% by weight retained on a #4 sieve (R > 15%), there is a significant amount of gravel, and the suffix "with gravel" may be added to the group name, but the group symbol does not change. For example, SP-SM could refer to "poorly graded SAND with silt" or "poorly graded SAND with silt and gravel." Unified Soil Classification System The Unified Soil Classification System (USCS) is a soil classification system used in engineering and geology to describe the texture and grain size
Mike Gravel Washington, D.C. Short on campaign cash, he took public transportation to get to his announcement. (Gravel called for public financing of elections.) Other principal Gravel positions were the FairTax, withdrawal of U.S. troops from Iraq within 120 days, a single payer national health care system, and term limits. In particular, he had opposed the Iraq War from the beginning, and in 2006 Gravel said that U.S. troops in Iraq, as in Vietnam, had "died in vain". He also favored a regional peace initiative, as well as reparation payments for Iraqis. Gravel also called for a "U.S. corporate withdrawal from Iraq",