NEHRP Clearinghouse

Title
Estimating In situ Liquefaction Potential and Permanent Ground Displacements Due to Liquefaction for the Siting of Lifelines.
File
PB93178614.pdf
Author(s)
Glaser, S. D.
Source
March 1993, 108 p.
Identifying Number(s)
NISTIR-5150
Abstract
The report examines the state-of-the-art of two aspects of the liquefaction problem with special attention to lifelines. In situ methods of estimating liquefaction potential are studied, since it is believed to be impossible to test in the laboratory an 'undisturbed' sample of loose sand, which is most susceptible to liquefaction. The state-of-practice is the SPT-based method championed by Seed, although the velocity-based predictors have a stronger physical basis. The Spectral Analysis of Surface Waves technique is especially suited for examining the large areal extents of lifeline routes. The state-of-the-art for estimating permanent ground displacements is purely empirical. Several methods are examined, and they all appear to have equal predictive abilities - within a factor of four. There have been a few recent attempts to construct constitutive models for post-liquefaction displacements, but at the time they are in formative stages and have not been rigorously proven.
Keywords
; Earthquake resistant structures; Sands; Earthquakes; Soil properties; Earth movements; Displacement; Soil mechanics; Mathematical models; Liquefaction; Seismic waves