| Consolidation settlement of soil has always been one of the problems studied in geotechnical engineering disciplines.Many scholars have improved one-dimensional consolidation theory on the basis of Terzaghi and deduced the specific conditions of one-dimensional or multidimensional consolidation partial differential equations.By studying the change of pore pressure in soil and the law of dissipation,we can understand the law of soil deformation intuitively and estimate the settlement of the structure.However,the solution of existing consolidation theory is too complex.It is often necessary to explore the law of pore pressure change through experiments and verify the correctness of the consolidation theory.In order to optimize the test program during the experiment,reasonably arrange the test volume and select the appropriate test method to improve the test accuracy.Sensitivity analysis was performed for each parameter of the consolidation partial differential equation under different conditions,the main mechanical parameters and secondary mechanical parameters that affect the pore pressure change in each analytical solution were determined.The parameter with high sensitivity is the main contradiction.In the experiment,by controlling the main contradictions that affecting the change of pore pressure to control the accuracy of the test,so that we can Reasonably arrange the appropriate test quantity for the most sensitive parameter.Therefore,it is necessary to do sensitivity analysis for the parameters of consolidation partial differential equation under different conditions,which provides reference and basis for the further study of the theory and the development of the experiment.This paper analyzes the sensitivity of the consolidation theory under different loading conditions,then deduce and validate the consolidation theory under continuous boundary conditions.The work done is as follows:(1)Analyze the parameter sensitivity of the solution to the One-dimensional consolidation theory under the conditions of double-sided drainage and load changes with time,then analyze the solution of two-dimensional consolidation under the conditions of double-sided drainage and uniform load with the same method.With the aid of mathematical calculation software,each solution was solved numerically.Single factor sensitivity analysis method was used to obtain the sensitivity sorting of the parameters for the excess pore pressure under different conditions.(2)A finite difference model was built in FLAC3 D to simulate the variation of the excess pore pressure under the above two conditions respectively.Sensitivity analysis was performed for each parameter by using single factor sensitivity analysis.The sensitivity analysis results obtained by comparing the two methods were compared.The parameters that are most sensitive to the excess pore pressure are determined.and verified the correctness of the sensitivity analysis by using analytic solutions.(3)Modified The continuous boundary conditions,then deduced the analytical solution formula of one-dimensional consolidation under the conditions of load changes with time.The analytical solution and the finite difference method are also used to verify the solution of the analytical solution.The results show that the two curves have a high degree of fitness.It verifies that the continuous boundary condition correction is feasible and the reliability of formula derivation.At the same time,a sensitivity analysis was performed on the analytical solution formula to determine the parameter that is most sensitive to the excess pore pressure.(4)Based on the continuous boundary conditions,the analytical solution formula of one-dimensional consolidation is deduced.The analytical results and the finite difference method are used to verify the derivation results.The results show the reliability of the derivation results.Then,a sensitivity analysis was performed on the analytical solution formula to determine the parameter that was most sensitive to the excess pore pressure. |
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