A new method for mapping liquefaction-induced lateral spread level

Abstract

To meet the objective requirements of civil engineering construction and mitigation of earthquake disasters, and achieve the goal of economic rationality, we propose a new method for liquefaction-induced lateral spread zonation that is adapted to regionalization and modern technology. To overcome the disadvantage of the National Earthquake Hazard Reduction Program (NEHRP) method that depends on high-density boreholes to complete zoning work, two key technologies of the new method are proposed in this paper, including liquefaction lateral spread level (LLSL) criteria and an extraction technique of polygon features to match the LLSL criteria, detailed as follows. (1) LLSL criteria are used to directly determine the lateral spread level within a certain range of each influence factor. (2) The extraction of polygon features for the influence factors. The geologic and soil condition factors are extracted by combining 3-D geographic information systems and a mining visualization system with geologic interpretation and fewer boreholes. The proposed method is used for the liquefaction-induced lateral spread distribution of a 7.8-magnitude earthquake south of Tangshan, China in 1976. The result is consistent with measurements just after that earthquake. This proves that the new method for liquefaction-induced lateral spread zonation is basically reasonable and feasible. The disadvantage of the NEHRP method, which depends on high-density boreholes, is thereby overcome. This can effectively cut economic costs and still keep the necessary accuracy in the sense of regionalization.