Numerical Simulation Of Overflow Boundary Of 3D Underground Cavern Seepage And Seepage Inversion Analysis

The free surface is the key to the numerical simulation of seepage field,and the distribution of seepage field in underground cavern is influenced by the excavation boundary with a lot of overflow boundaries are formed.In this paper,based on the improved variable inequality iterative algorithm of overflow boundary in the Signorini type,which makes the method faster convergence speed in underground seepage simulation,and high precision in the calculation of free surface and flow.Seepage field inversion is the main method to determine permeability coefficient,boundary condition and evaluation of engineering seepage stability.In this paper,The hybrid intelligent optimization algorithm combined with underground three-dimensional finite element overflow boundary seepage method to establish the double objective model of seepage field of underground cavern inversion,and applied to the Tianhuangping Pumped Storage Power Station for the seepage field inversion.Finally,the seepage stability is evaluated according to the inversion results.The main contents are as follows:(1)Introduces the basic concepts of Signorini type inequality,according to the basic expression of seepage finite element,the finite element formula for solving is derived with the basic ideas of variational method,and the finite element calculation formula is given to determine the flow.Thus,numerical simulation of underground cavern seepage theory is given.(2)Based on the variational inequalities of seepage free surface calculation which Zheng Hong put forward,the underground cavern overflow boundary simulation method is built.The convergence condition and iterative process is changed which improve the convergence speed and precision.The program can effectively calculate the underground seepage free surface and seepage flow,and verified through numerical examples.(3)Through a simple comparison of several intelligent methods,particle swarm optimization and bacterial foraging optimization hybrid algorithm is applied to the seepage inversion calculation,the head error and flow error inversion algorithm of double objective function is established,the model and calculation method is given for seepage inversion analysis.The 3D seepage field calculation program of underground cavern is combined.with the program of the optimization algorithm to form the three-dimensional seepage field inversion program of underground cavern,and is verified by an example.(4)Establishing the Tianhuangping Pumped Storage Power Station Underground three-dimensional finite element model,according to the monitoring data,using underground caverns in three-dimensional seepage field inversion program to do inversion calculation,and evaluate the inversion effect.Evaluation of seepage characteristics of rock mass and curtain by inversion results.