Seismic Earthquake Liquefaction Potential

EARTHQUAKE_LIQUEFACTION_POTENTIAL_MM81_IN is a polygon shapefile that shows highly generalized categories (low, moderate, and high) of liquefaction potential, based on soil classes of the National Earthquake Hazards Reduction Program (NEHRP). Low liquefaction potential includes NEHRP Soil Class B (consisting of rock: sandstone, limestone, shale). Moderate liquefaction potential includes NEHRP Soil Class C (hard or stiff soil, or gravel) and part of NEHRP Soil Class D (stiff soil, stiff clay, and some gravel). High liquefaction potential includes parts of NEHRP Soil Class D (stiff soil, stiff clay, and some gravel), and all of NEHRP Soil Class E (soft soil and soft to medium clay) and F (lake and river deposits of sand and mud). The following is excerpted from Indiana Geological Survey Miscellaneous Map 81: "Liquefaction is a common ground-failure hazard associated with earthquakes. It is defined as the sudden and temporary loss of strength of a water-saturated sediment. This could result in the structural failure of buildings, bridges, and other structures."EARTHQUAKE_LIQUEFACTION_POTENTIAL_MM81_IN 是一款多边形形状文件（shapefile），基于美国国家地震灾害减轻计划（National Earthquake Hazards Reduction Program, NEHRP）的土壤分类标准，展示了液化势的高度概化分级（低、中、高）。其中，低液化势涵盖NEHRP土壤类别B（由岩石构成：砂岩、石灰岩、页岩）；中液化势涵盖NEHRP土壤类别C（坚硬或密实土壤、砾石）以及NEHRP土壤类别D的一部分（密实土壤、硬黏土及部分砾石）；高液化势涵盖NEHRP土壤类别D的一部分（密实土壤、硬黏土及部分砾石），以及NEHRP土壤类别E（软土、软至中等硬度黏土）和F（砂与淤泥的河湖沉积物）的全部范围。以下内容节选自印第安纳地质调查局杂项地图81："液化是与地震相关的常见地面破坏灾害，其定义为饱水沉积物的强度发生突发性、暂时性丧失，这可能导致建筑物、桥梁及其他结构发生结构性破坏。"