Calculating Method Of Foundation Deformation Parameters & Foundation Reinforcement Optimization For High Arch Dam

Arch-cantilever method is still the main method of arch dam structural analysis. The deformation modulus and poisson's ratio of dam foundation rock in different elevation need to be properly determined by using the arch-cantilever method for stress analysis. Most of the arch dam is built on rock foundation composed of a variety of rock, so the comprehensive deformation parameters of the foundation is not only concerned with the single rock mass deformation parameters, but also with the ratio of the thickness and strata dip, which is unreasonable by using any a kind of rock deformation parameters instead of rock mass deformation parameters, or simple average all the rock mass deformation parameters. It is necessary to explore more rational method for calculting the comprehensive deformation parameters of the arch dam foundationHigh arch dam is a high indeterminate space shell structures. It is very strict with the topographic and geologic conditions on the valley sides because the arch dam load is primarily passed to the both sides by the arch effec. In fact, the objective condition often is not satisfied with the requirements, so some appropriate measures for foundation treatment and structure should be taken to meet the design requirements. It is still not a good way to draft the foundation reinforcement scheme with less cost and more favorable for dam safetyIn this paper, the comprehensive deformation parameters calculation method for the world's highest Jinping arch dam is proposed based on finite element method, the multi-objective optimization models on foundation deformation parameters is established, and a new foundation treatment scheme based on optimization analysis and sensitivity analysis is put forward. A system from calculting comprehensive deformation parameters to determining foundation treatment measures based on optimization analysis is formed. Such as the major content:(1)The common method of calculting composite materials equivalent deformation parameters in micromechanics is summarized, and the method of calculting the foundation deformation parameters are proposed by the results of three-dimensional finite element method. It shows this method is reasonable by comparing the result with the theoretical solution in micromechanics.(2)Three-dimensional finite element model is established by considering faults, weak zone, concrete replacement and grouting depth in the vicinity of Jinping arch dam, the Jinping arch dam comprehensive deformation parameters is computed by using the proposed method, and stress and deformation analysis is also carried out.(3)Mathematical optimization model on foundation deformation modulus is established by using multi-objective linear programming theory. In this model, the arch-cantilever method and finite element method as the stress re-analysis method, the foundation deformation modulus E as the design variables, the multi-objective linear programming method is used to find a group foundation deformation modulus which is the best for dam stress, stability, deformation and foundation treatment cost within the foundation deformation modulus's man-made changing range.(4)Stress sensitivity analysis on Jinping arch dam concerning the foundation deformation parameters is carried out. It shows the influence on arch dam stress and the arch dam adaptability with the changing foundation deformation modulus whiles the foundation deformation modulus floating within a certain range. Based on optimization analysis and sensitivity analysis, new Jinping arch dam foundation treatment scheme is given.