DEFINITION AND DETERMINATION OF CHARACTERISTIC SOIL PROPERTIES

The fundamental soil parameter used in EC7 "Geotechnics" is the characteristic value Xk from which the design value Xd is derived. These soil parameters are defined and compared to today's practice. A simple approach, derived from fundamental statistics and probability concepts, is proposed for the selection of the characteristic values. The approach presented in this paper is based entirely on today's practice. It offers an extension to incorporate experience or judgmental knowledge as well as test values to produce characteristic values Xk. The resulting characteristic values are equally valid using the EC7 approach as well as for today's method. The proposed equation is derived from fundamental concepts of statistics and probability, yet the design engineer does not need to acquire those concepts to successfully employ the method presented. An illustrative example to demonstrate the application of the method is given.