One test determination of the failure curve of a granular soil by strain path testing

The determination of a curved failure surface of a granular soil can be a time and cost consuming exercise. The fitting of a failure curve to failure points obtained by testing different, but supposedly replicate, samples can also be an error-prone process. A new, but simple, method based on post-failure strain path testing is presented. Micro-processor control techniques are used to control the strain path followed by a sample in a post-failure domain. This new method enables the determination of the failure curve from a one test. The pre-requisite of the success of this method is elimination of platen restraint to a minimal level.