Can a Pile Load Tested to ‘Failure’ be Used as a Working Pile?

Abstract

There are a few available loading test methods to obtain a load-settlement curve of a pile. Likewise, there are many definitions to determine the ‘ultimate’ pile capacity from a load-settlement curve. Although pile load tests have been widely used over the past decades, there are still many questions regarding its practice and interpretation. Frequently asked questions include: when does a pile test considered to have failed? From an economic point of view, a failure in pile loading test can cost quite a lot of money. To what load can the pile be loaded till it is considered to have failed? Can a pile loaded to failure still be used as a working pile? What is a bidirectional pile load test (BD-test)? When should a BD-test be used? Can a pile tested with a BD be used as a working pile? What are the differences between kentledge or reaction piles static loading test with the bidirectional test? Do the different pile tests produce the same results? This paper aims to shed light on these questions, one case history where the pile tested to ‘failure’ and later used as working piles is presented.