THEORETICAL RESEARCH AND EXPERIMENTAL VERIFICATION ON CONSOLIDATION STAGE OF CONVENTIONAL TRIAXIAL COMPRESSION TEST

The consolidation process of the conventional triaxial compression test is a three-dimensional compression under the action of spheric stress while seepage occurs only in the vertical direction，which has differences and some similarities with the process of Terzaghis one-dimensional consolidation． Therefore，Terzaghis one-dimensional consolidation theory cant be used directly to solve the problem． Based on the effective stress principle，Darcys law and the assumption of linear material，a water pressure dissipation theory equation was set up for consolidation stage of conventional triaxial compression test，and the corresponding power series solution derived from the method of separation of variables and the finite element solution were provided． The example analysis showed that the solution of power series had poor astringency in the early stage of consolidation but good stability when the degree of consolidation is slightly larger． A comparison of the calculation results of the theoretical equation with test results of the double pressure chamber effective stress path triaxial compression test indicated that the theoretical equation could reveal the main characteristics of the consolidation stage of triaxial test． Theoretical analysis showed that，the difference lay mainly in the objective existence that ideal assumption and real soil properties were not exactly uniform．