An overview of soil heterogeneity: quantification and implications on geotechnical field problems

Abstract

Engineering judgment and reliance on factors of safety have been the conventional tools for dealing with soil heterogeneity in geotechnical practice. This paper presents a review of recent advances in treating soil variability. It presents the implications of geostatistical techniques and up-scaling methods used for quantifying the heterogeneous permeability of soil as addressed in the petroleum industry. Moreover, the interest of geotechnical practice to incorporate the statistical properties of soil in a probabilistic design framework is also discussed. This ranges from conventional Monte Carlo simulation based design and stochastic finite element analysis to the recent techniques that take into account the effect of spatial correlation of soil properties. Example applications of these techniques to different types of field problems, such as foundation settlement, seepage flow, and liquefaction assessment, are discussed with emphasis on the limitations of the current practice and trends for future research. In addition, different decision making algorithms are addressed with examples of their applications to geotechnical field problems.Key words: heterogeneity, spatial variability, geostatistics, stochastic analysis, decision making.