Safety factors in soil mechanics

Abstract

The influences on the safety margin in earthwork and foundation engineering are considered in relation to soil exploration and tests, analysis of stability under the applied loads, and construction and operation of the structure during its service life. Customary overall and suggested partial safety factors used in stability analyses are mainly governed by the variability and uncertainty of assessment of the soil resistance, the variability of the applied loads, approximations in the stability analyses, and the seriousness of a failure. On the basis of probability concepts of safety, the conventional overall safety factors used in earthwork and foundation engineering analyses are related to approximate probabilities of stability failure and to a range of overall coefficients of variation, which are consistent with the range of observed coefficients of variation of the soil resistance, applied loads, and stability analyses.