Reliability-based design cost optimization of laterally loaded drilled shafts considering spatial variability of clays

ABSTRACT: A procedure for the reliability-based design cost optimization of laterally loaded drilled shafts considering spatial variability of soil properties is presented. The finite difference method implemented with p-y curves to predict the performance of laterally loaded drilled shafts. The spatial variability of soil parameters is modeled with random field combined with Monte Carlo simulation. For combinations of shaft diameter and shaft length, random finite difference modeling is conducted to compute the probability of serviceability failure (exceeding the limiting maximum lateral shaft deflection). Using recent bidding cost data, the reliability-based design cost optimization of laterally loaded drilled shafts demonstrates that although several combinations of shaft diameter/shaft length can meet the acceptable probability of failure, the final design decision can be readily determined by choosing the design with the minimum cost.