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/美国地质勘探局在国家减少地震危害方案（NEHRP）下的倡议的一部分，目的是调查1989年10月17日洛马普列塔地震的影响。该研究项目由美国国家科学基金会和美国地质调查局共同资助。它利用车载20吨电子锥形穿透系统（用于土壤穿透测量），以及独特的实验室测试系统，便于测量土壤中的初级(P)和次级(S)地震波。它们一起可以精确地测定土壤中的原位应力。土壤测量包括锥贯试验（CPT）、地震-CPT、Marchetti平面膨胀仪（DMT）和弯曲单元测深仪（BEO）。本研究的目的是：(1)补充现有的锥尖阻力、横波速度和膨胀仪指标与液化势的关系数据库；(2)研究侧向土压力对液化势的影响；(3)研究土体扰动和时间（老化）对土体刚度和强度的影响。

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.