Review of methods of analysis of test results from bi-directional static load tests

Results from bi-directional tests are not the same as those obtained from top loading tests and although bi-directional test data often contain more geotechnical information, it is the characteristic behaviour of the head of the pile which is of interest. In order to provide an equivalent top loading characteristic, methods have been developed to enable the addition of the individual components measured. Bi-directional loading test results automatically separate the resistance of each component which then require suitable combination and analysis to reconstruct the equivalent top load characteristic of the pile. This paper aims to describe and review the merits of some of the direct methods currently employed and some of the analysis methods which can be used as well as the application of finite element analyses using measured behaviour.