FIELD EVALUATION OF LIQUEFACTION POTENTIAL BY ARIAS INTENSITY DUE TO IMPACT LOADING

Shannon & Wilson Inc, Seattle WA

Investigators

Abstract

The liquefaction of loose, saturated, cohesionless soils due to earthquake loading has been studied extensively over the past 35 years, resulting in both laboratory and empirically based procedures to evaluate liquefaction potential. Kayen and Mitchell (1997) proposed an earthquake-based approach based on Arias intensity to assess liquefaction potential that has proven to be highly reliable. (The Arias intensity indirectly accounts for both magnitude and duration of an earthquake motion.) We propose to evaluate the applicability of the Kayen and Mitchell (1997) method for liquefaction evaluation to other (non-seismic) types of loading. The source of the load is the implosion of the Kingdome in downtown Seattle, which took place on March 26, 2000. The Kingdome foundation soils consist of potentially liquefiable fill and alluvial sediments; however, before the implosion there was no established procedure to evaluate whether the soils would liquefy due to the impact produced by the falling structure. Shannon & Wilson installed an array of downhole and surface instruments to measure ground motion and pore pressure generated by the falling pieces of concrete. This sort of impact load is analogous to loads produced by deep-dynamic compaction, a commonly used soil improvement method. We propose to analyze the data collected by Shannon & Wilson during the Kingdome implosion to assess the usefulness of applying earthquake-based liquefaction concepts to liquefaction induced by conventional demolition/site improvement techniques