Cost-Benefit Analysis of Routine Quality Assurance for Bored Piles

To ensure safety of bored piles and avoid excessively conservative designs, quality assurance (QA) tests, such as integrity tests, are routinely performed after pile construction. The impact of a specific QA test on the reliability of piles can be translated into monetary values. This paper aims to quantitatively evaluate the cost-benefit of QA tests for bored piles. A cost-benefit model for QA tests is formulated. The role of a QA program is quantified through the changes in the probabilities of pile failure before and after the implementation of the QA program. An example is presented to illustrate the proposed procedure. The results indicate that the updated probability of failure can be significantly smaller than that before the QA tests. The degree of reliability improvement and the cost effectiveness depend on the pile specifics, the availability of prior information, and outcomes from the QA tests.