Testing the Liquefaction (Ground Failure) Sites Resulting from the 1989 Loma Prieta Earthquake

该项目是美国国家科学基金会/美国地质勘探局国家减少地震灾害计划(NEHRP)倡议的一部分，目的是调查1989年10月17日洛马普里塔地震的影响。这项研究计划涉及美国国家科学基金会和美国地质调查局之间的合作资金。它使用车载20吨电子触探系统(用于土壤中的触探测量)，以及独特的实验室测试系统，便于测量土壤中的一次(P)和二次(S)地震波。它们结合在一起，可以准确地确定土壤中的地应力。土的测试包括静力触探试验(CPT)、地震触探试验(CPT)、Marchetti扁平膨胀仪(DMT)和弯曲单元固结仪(BEO)。本研究的目的是：(1)补充现有的锥尖阻力、剪切波速和膨胀计指数与液化势的关系的数据库，(2)研究侧向土压力对土的液化势的影响；(3)研究土的扰动和时间(老化)对土的刚度和强度的影响。

This project is part of the NSF/USGS initiative within the National Earthquake Hazard Reduction Program (NEHRP) to investigate the effects of the Loma Prieta earthquake of 17 October 1989. This research program involves collaborative funding between the National Science Foundation and the U.S. Geological Survey. It utilizes a truck-mounted 20 ton electronic cone penetration system (for penetration measurements in soil), as well as a unique laboratory testing system which facilitates measurement of primary (P) and secondary (S) seismic waves in soils. Together, they permit the accurate determination of in-situ stresses in the soil. The soil measurements include the cone penetration test (CPT), seismic-CPT, the Marchetti Flat Dilatometer (DMT) and the bender element oedometer (BEO). The objectives of this research are: (1) to supplement the existing data base of cone tip resistance, shear wave velocity, and dilatometer indices versus liquefaction potential, (2) to investigate the effects of lateral earth pressures on the liquefaction potential, and (3) to study the effects of soil disturbance and time (aging) on soil stiffness and strength.