Review of evaluation of uncertaintyin soil property estimates from geotechnical investigation

Abstract

Geotechnical investigations are carried out for important projects in nuclear industries. Investigations involve estimation of soil properties by various laboratory and in situ tests. Estimation of accurate geotechnical parameters is needed in design process. The uncertainties involved in soil property estimates have necessitated reliability analysis in addition to conventional analysis. Unavailability of a large set of sample data and mathematical sophistication for carrying out uncertainty analysis are areas of concern. Reliability based design is done considering individual sources of uncertainties. Quantitative analysis of uncertainty is carried out. Standard deviations (SD) of various parameters need to be evaluated based on the data. There is degree of uncertainties in the calculation of parameters. Varying degree of uncertainties has been observed for different parameters. For some parameters, it is low and for some, it is high which need to be considered in reliability analysis. When sufficient data is available, SD is calculated directly from data. When sufficient data is not available, published value of Values of Coefficient of Variation (COV) is used which when multiplied with mean value gives standard deviation. This paper presents review of evaluation of uncertainties in soil property estimates.