Cone penetration-induced pore pressure distribution and dissipation

摘要

The excess pore water pressure distribution (u) induced by the penetration of a piezocone into clay and its dissipation behaviour have been investigated by laboratory model tests, theoretical analysis and numerical simulation. Based on the results of the tests and the analysis, a semi-theoretical method has been proposed to predict the piezocone penetration-induced pore pressure distribution in the radial direction from the shoulder of the cone. The method can consider the effect of the undrained shear strength (s_u), over-consolidation ratio (OCR) and rigidity index (I_r) of the soil. With a reliably predicted initial distribution of u and the measured curve of dissipation of pore water pressure at the shoulder of the cone (u_2), the coefficient of consolidation of the soil in the horizontal direction (c_h) can be back-fitted by analysis of the pore pressure dissipation. Comparing the back-fitted values of C_h, with the values directly estimated by a previously proposed method indicates that the previously proposed method can be used reliably to estimate c_h values from non-standard dissipation curves (where u_2 increases initially and then dissipates with time).