Design Under Stochastic Groundwater Fluctuation

A foundation is to be protected against the harmful effects of sulfure groundwater, whose piezometric head fluctuates in a random manner. The stochastic process forms a partial duration series, where the jth event is defined by the maximum exceedance above the foundation floor, the duration and interarrival time until the (j+1)st event. To protect the structure against possible damage by high levels of groundwater with substantial sulfate concentration, it is possible to make four decisions, corresponding to waterproofing or using special sulfate resistant concrete or both, or providing no protection. The annual cost and expected loss associated with each of these four decisions is calculated, with the help of explicit expressions. Sensitivity of the decision to sample, model, and economic uncertainty is analyzed as well as the possibility of using a Bayesian approach to account for sample uncertainty.