Abstract: Having the origin from the sedimentation of volcanic materials, many experienced Indonesian geotechnical engineers have long suspected that Jakarta reddish and grayish clay may have different characteristics compared to other clayey soils known in many geotechnical text books. Despite of carefully derived design parameters, experiences in the execution of deep excavation, be it open cut slope or protected excavation by either contiguous bored pile or diaphragm walls, often show that the performance of the geotechnical structures were better than predicted by the available design geotechnical software. Although, some engineers have started using more advanced constitutive soil models, such as: Hyperbolic and Cam Clay models. Undoubtedly, many engineers still use the bilinear Mohr-Coulomb model in their analysis. So far, to the author knowledge, there is no published paper discussing about the suitability of the soil models for modelling Jakarta red clay, in particular. Therefore, the author tried to find out which soil constitutive models can better predict the behavior of the Jakarta reddish/grayish clay. Available models in PLAXIS software, e.g.; Mohr-Coulomb, Hardening (hyperbolic), and Soft Soil models, were tried by simulating isotropically consolidated undrained triaxial test and compared it with the actual test data. At this stage it was found that none of the model can correctly predict the stress strain curve neither the correct stress path.

Download Full Paper: GOUW-2014-1021-FindingSuitableModel