Constitutive modeling of San Francisco Bay mud

Conventional laboratory tests on undisturbed samples of a highly plastic silt are described. Modified Cam Clay Model (MCC) is formulated and verified against the laboratory tests. Next, in-situ self-boring pressuremeter (SBPM) tests in the same soil are described. In order to simulate the SBPM tests, a finite element model is constructed incorporating the MCC model and the Biot's theory of consolidation. The numerical model is used to predict field SBPM tests. The predictions (or simulations) are compared with the field data from SBPM tests. The paper attempts to answer an important question in constitutive modeling: Can a constitutive model based on laboratory tests generate the response actually observed in the field? The paper concludes that it is possible to formulate a satisfactory model based on conventional laboratory tests. But, it is only when a permeability value determined by a field test is used, can an acceptable match be found between the data generated by the numerical model and the actual field data.