Updating Statistics of Multiple Defects in Bored Piles

Abstract

Due to errors in handling slurry, concrete, casings, reinforcement cages and other factors, minor or major defects in bored piles may be introduced during or after pile construction. This paper aims to propose a procedure to estimate the occurrence of multiple defects in bored piles. This procedure is formalised in the Bayesian framework. A Poisson process is adopted to model the occurrence of multiple defects in bored piles. Moreover a method to update mean rate of defect occurrence with a consideration of inspection uncertainties is formulated. Results from numerical example indicate that the updated mean rate of defect occurrence depends on the inspection probability of integrity tests, the inspection results, the inspected defect sizes, and the pile specifics. The Bayesian estimator of mean rate of occurrence will be significantly underestimated without consideration of inspection uncertainties. The updated mean of mean rate of occurrence increases with increasing values of the number of inspected def...