NUMERICAL-ANALYSIS OF THE MINIATURE PIEZOCONE PENETRATION TESTS (PCPT) IN COHESIVE SOILS

An analytical model to simulate the penetration of the piezocone penet rometer in cohesive soils is presented here. The elasto-plastic couple d field equations of the saturated cohesive soils (given by Voyiadjis and Abu-Farsakh(1)) is used in this analysis. The numerical simulation of the piezocone penetration is implemented into a finite element pro gram. The analytical model is used to analyze the miniature piezocone penetration tests (PCPT) conducted at LSU calibration chambers. Simula tion of the piezocone penetration is done for two cases. In the first case, the soil-penetrometer interface friction is neglected, while in the second case, the soil-penetrometer interface friction is taken int o consideration. The constraint approach is used to model the soil-pie zocone interface friction in which the Mohr-Coulomb frictional model i s used to define the sliding potential. Analysis is done for three dif ferent soil specimens with different stress histories. The results of the numerical simulations are compared with the experimental measureme nts of the miniature piezocone penetration tests (PCPT) in cohesive so il specimens conducted in LSU calibration chambers. The resulting exce ss pore pressure distribution and its dissipation using the numerical model are compared with some available prediction methods. (C) 1998 Jo hn Wiley & Sons, Ltd.