Probabilistic Pore Pressure Analysis for Seismic Loading

Abstract

TWO probabilistic models are proposed to study the development of pore pressure in saturated sands under random loading. The first of these is based on laboratory data, while the second uses an analytically based effective stress technique. Both incorporate uncertainties in soil parameters, laboratory data, and earthquake loading parameters, and compute the cumulative distribution function of pore pressure at the end of any cycle of loading. The two models are cast into a methodology which evaluates the probability of developing a certain level of pore pressure over a given time frame under a specified probability of seismic loading. They allow probabilities to be defined as to the generation of any pore pressure ratio from 0 to 1. They are suited to assess the relative effects of soil resistance, seismic environment, and geotechnical uncertainty. Limitations in application of the methods lie primarily in definition of soil and seismological parameters; however, future basic research should help to resolve this problem.