Analysis And Evaluation On Optimization Of Design For Foundation Interface Of Super High Arch Dam

Analysis and evaluation on optimization of design for foundation interface of super high arch dams is one of the most important research fields of hydraulic engineering. It is significant also for engineering and academic study, and for proposing new design criteria of super high arch dam or revising arch dam design standard. This thesis investigated the failure mechanics of jointed rock mass for proposing a plastic damage model of jointed rock mass, then, carried out quantitatively analysis of reinforcement force by employing the reinforcement theory considering deformation mechanism of rock mass. This thesis also proposes evaluation criteria for super high arch dam based on general analysis and nonlinear numerical simulation method, and applies proposed criteria for optimization of foundation interface of Xiluodu arch dam. The major contents of this thesis are as follows:(1) To investigate the failure process and peak strength of rock mass containing 3D(three dimension) joints under 3D compression, a serial of the physical test on 3D jointed specimen made by Xiluodu rock mass for obtaining the qualitative relationship of peak strength and damage were carried out. Based the experimental results and in situ probability investigation, a plastic damage model of jointed rock mass in considering crack initiation, propagation and interaction is proposed. In this thesis, the work flow of finite element method with applying this model is given.(2) Based on 3D nonlinear finite element method for analyzing the integrity stabilization of arch dam, by using non-equilibrium elastic-plastic damage mechanics, and minimum plastic complementary energy principle, the reinforcement theory considering deformation mechanism of rock mass is proposed, which can quantitatively calculate the reinforcement force of foundation in dam toe area.(3) In this thesis, an evaluation criteria, design concept and flow of optimization of design, evaluation data and criteria of typical stability analysis methods are discussed for proposing the analysis and estimation system on optimization of design for foundation interface of super high arch dam.(4) Based on general evaluation method, the 3D nonlinear finite element method and 3D geomechanical model test, by employing the proposed analysis and estimation system, different foundation excavation cases of Xiluodu arch dam including research case, optimization case and comparison case, respectively, are analyzed and evaluated. The investigation results demonstrated the feasibility of using III1, III2 typical rock mass as foundation interface of Xiluodu arch dam. With the optimization case in Xiluodu arch dam, to compare the research case, the excavation of foundation and concrete quantities of dam will minimize about one million cubic meters; as a result, nearly 600 million RMB of investment is saved.