Click the title below to display the complete page!

Condition indicators for liquefaction susceptibility with focus on silty soils

Abstract:

Deformation of the sub-soil is one of the major risk scenarios being confronted in the event of earthquakes. One of the mechanisms involved in causing large deformations under cyclic loading is lique-faction observed for granular soil conditions. This phenomenon has been studied in a lot of research projects mainly in sandy soils. Recent earthquakes have shown that the range of soils prone to liquefaction is wider than assumed and that the nature of the earthquake has to be regarded as one condition indicator for a soil to reach liquefaction as well. Condition indicators used are based on field investigation or on grain size distribu-tion and Atterberg-limits. Studies on other influencing factors are conducted in the laboratory with cyclic in-vestigations. Among those tests, variations in soil graduation curves are rarely studied. Focus is given mainly to the amount of fines for mostly equivalent void ratios for silty soils. As a reasonable basis for defining con-dition indicators studies on liquefaction susceptibility of silts and sands with fine contents are reviewed. This review sets the base for an upcoming study in the frame of an interdisciplinary research project on developing a generic method on Management of Risk using condition indicators. The first result of the review leads to the proposal of a dimensionless correlation between the physical state of the soil using the permeability coeffi-cient with a load function. The studies being introduced here will aim to develop an analytical description of liquefaction potential of silty soils to be able to define the condition indicators to subdivide the mechanism leading to strain hardening, strain softening and, in the worst case, liquefaction.

Authors:

Laue, Jan and Buchheister, Juliane

Index Terms:

Soil; liquefaction; silt; SoilGroup; Buchheister, Juliane; Laue, Jan

Further Information:

Date published: 31.03.2004