NEHRP Clearinghouse

Guidelines for Evaluating Liquefaction Resistance Using Shear Wave Velocity Measurement and Simplified Procedures.
Andrus, R. D.; Stokoe, K. H.; Chung, R. M.; Juang, C. H.
National Inst. of Standards and Technology, Gaithersburg, MD., July 2003, 176 p.
Predicting the liquefaction resistance of soil is an important step in the engineering design of new and the retrofit existing structures in earthquake-prone regions. The procedure currently used in the U.S. and throughout much of the world to predict liquefaction resistance is termed the simplified procedure. This simplified procedure was originally developed by H.B. Seed and I.M. Idriss in the late 1960s using blow count from the Standard Penetration Test. Small-strain shear wave velocity measurements provide a promising supplement and in some cases, where only geophysical measurements are possible, may be the only alternative to the penetration-based approach. This report presents guidelines for evaluating liquefaction resistance using shear wave velocity measurements. These guidelines were written in cooperation with industry, researchers and practitioners, and evolved from workshops in 1996 and 1998 as well as review comments received on an earlier draft. The guidelines present a recommended procedure, which follows the general format of the penetration-based simplified procedure.
Buildings; Soil liquefaction; Earthquake engineering; Guidelines; Seismic design; Evaluation; Shear wave velocity; Soil properties; Secondary waves; Cyclic loads; In situ; Liquefaction; Retrofitting