Research On Dynamic Interaction Of Gravity Dam-storage Water-sludge Layer System

In the western of China where is a strong seismic belt,a number of high dams are going to be constructed,therefore,the research and analysis of earthquake resistance of the high dams built in the strong seismic belt is very urgent.There are two commonly used research methods:one is numerical simulation and the other is model test.In the past research,some scholars have combined the two research methods together in order to verify the reliabilities of the test result and numerical simulation.After the establishment of the concrete gravity dam,the dam-reservoir water-siltation layer constitutes an integrated system in which the above mentioned three will have interaction,mutual influence and co-operation on each.When studying the seismic performance of dams,the interaction of the integrated system must be taken into consideration.(1)In order to reproduce the dynamic failure characteristics of the gravity dam is under earthquake action,the simulation concrete materials must have similar mechanical properties as the original raw materials,and only in this case,it can get the failure model which is as similar as the prototype.Therefore,this paper not only studies the dynamic mechanical properties of the simulation concrete materials,but also supplies reliable basis for the selection of the dynamic model test materials by changing the material mix ratio and doing the uniaxial compression test of the simulation concrete materials and doing the cube cantilever beam test.(2)The paper preliminarily discusses the conditions that need to meet when carry out the dynamic model test,including the similarity conditions of the prototype and simulation model,the similar rules of the elastic model material test and the similar rules of the nonlinear model material test.Choose the suitable similar rules that are in line with the actual situation of the model test design according to the derived formula.The stress and strain factors that affect the prototype and model are plenty;therefore,the similarity scale must be determined according to the reality.The fundamental quantities must be determined first,and then work out the similarity scales of other physical quantities by calculation,so as to reduce the difficulty of experiment design.(3)In order to study the failure mechanism and form of the concrete gravity dam is under earthquake action and the influence of the siltation layer on the dam seismic effect,the dynamic model failure test has been done.The siltation layer is compared with different thickness,and the test results are revealed by adding the speed,fundamental frequency,strain and hydrodynamic pressure.The test results show that the dam neck is the weak point when the dam is under earthquake action,and the siltation layer has a certain inhibitory effect on the seismic responses of the dam.(4)In order to study the dynamic interaction of the dam-reservoir water-siltation layer system and the reliability of the dynamic model test results,the paper compares the numerical simulation test results and the experimental results;it is found that the test results of the numerical simulation test and the experiments are the same.