Laboratory Study of Compressional Liquefaction

Abstract

A new experimental apparatus has been developed to investigate the transient and long‐term pore‐water pressure response of saturated soils subject to compressional stress‐wave loading. The laboratory apparatus is capable of generating compressive shock pulses on the order of 35,000 kPa having submillisecond rise times to peak stress. The experimental investigation was conducted to examine and establish an understanding of compressionally induced liquefaction in saturated soils. Specimens of water‐saturated Monterey No. 0/30 sand were tested at various relative densities and effective stresses. Boundary conditions were for one‐dimensional, confined compressive loadings without drainage. Results indicate that it is possible to liquefy Monterey No. 0/30 sand under these conditions. Significant residual pore‐water pressure increases were observed even at high relative densities and high effective stresses. The data suggest that a transient strain exceeding approximately 0.005% may result in explosively induced residual pore‐water pressure increases. Several empirical models are presented for estimating liquefaction potential as a function of initial relative density, initial effective stress, and the magnitude of the applied compressive strain.