Numerical Investigation of Pressuremeter Test with Material Point Method

                                
==Abstract==

In situ tests for geotechnical investigations can provide a reliable prediction of the soil behaviour because they accurately represent the stress state while preserving the soil structure and the inherent material fabric. These tests complement the information obtained from laboratory element tests on undisturbed or reconstituted specimens. The pressuremeter test is one such example of an in-situ tool that is used to obtain soil properties based on measured pressure-volume data. The pressuremeter test is considered a large deformation problem within a numerical framework. Furthermore, it is commonly idealized as a cylindrical cavity expansion within the realms of conventional finite element schemes. In order to address the issue related to excessive mesh distortion aspects, the Eulerian-Lagrangian approach developed within a continuum framework, namely the Material Point Method (MPM), has been adopted in the present study to investigate the pressuremeter expansion process. First, the results obtained are benchmarked against those from classical cavity expansion problems for a pressure-dependent frictional material. The computed results are in good agreement with both the closed-form solutions and displacement-controlled experiments reported in the literature. A parametric study was performed to further investigate the influence of the loading rate, material properties, and heterogeneities on the pressuremeter test simulations.