Research On Seismic Dynamic Response Of Rock-filled Concrete Gravity Dam Based On Meso Scale And Macro Scale

Due to the large size,rock-filled concrete cannot be used to study the destruction mechanism of the actual size model through routine tests,and as the application of rock-filled concrete in large-scale concrete projects such as dams and nuclear power plants is becoming more and more extensive,The research on damage and destruction in China has also become an urgent problem to be solved.In this paper,based on the meso-mechanical theory,the rock-filled concrete is regarded as a composite material,and a random aggregate dropping algorithm is studied to establish a meso-scopic model that can reflect different components of the rock-filled concrete and is closer to the actual aggregate shape,and destroy the meso-structure correlate with the macroscopic deformation response of concrete materials.Combined with the actual situation,the numerical method is used to analyze the seismic dynamic response of the macro and meso rock-filled dam.The main research contents include the following aspects:(1)Based on the round aggregate generation and delivery method,using MATLAB language combined with the Monte Carlo method for secondary development,we independently wrote the convex polygon aggregate random generation and placement algorithm program,and used the Walavin formula to obtain the number of different levels of aggregate particles,build a convex polygonal random aggregate model,which makes the aggregate shape more consistent with the actual situation,and can meet the requirements of aggregate gradation and content.(2)According to the MATLAB language,the program is secondary developed,and the graphics display interface file is written to enable the MATLAB program results to be imported into the ABAQUS/Explicit finite element software to form a pre-processing model.(3)Modeling a single-sided notched beam by using the compiled aggregate algorithm,and a four-point shear numerical simulation was performed on the notched beam using a concrete plastic damage mechanical model.The simulation results of the model were basically consistent with the tests,and the correct reliability of the program and model was verified.(4)Based on the ABAQU/Explicit finite element software,the additional mass method is used to implement the application of hydrodynamic effects through the self-developed subprogram module.Considering the effect of hydrodynamic pressure on the dam body,a macro model of rock-filled dam is established to carry out the rock-filled gravity dam dynamic time history analysis,to explore the impact of different tensile strength on the dynamic response of rock-filled dam under earthquake,and to discuss the distribution of stress and displacement.(5)Combining the proposed aggregate algorithm program with the actual situation,a meso-scopic rock-filled gravity dam model is established,the dynamic response data of the rock-filled gravity dam is analyzed,and the key points of the dam body are analyzed,such as the key point displacement,stress and damage the response law of the dam under dynamic load has guiding significance and theoretical reference value for the research on the damage of rock-filled dam under earthquake and the seismic design of similar projects.