Dynamic Damage Analysis Of Concrete Gravity Dams

China is one of the most rich countries in hydropower resources of the world. In consideration of the abundance of the hydropower, there will be constructed quite a few high concrete dams in the southwestern region. Because of the strong earthquake in the western region, in-depth research for the seismic damage of the concrete dams are conducted in this paper. The consideration of the tensile nonlinear of concrete materials is based on macro homogeneous assumption. According to the secondary development of ANSYS, the constitutive relationship of elastic damage mechanics is implanted in the calculation process by the way of updating the stiffness. As an easy operating'analysis method, the dynamic damage model is set up, and it is applied to study the seismic damage of Kala gravity dam. The contents of this paper include the following three aspects:(1) The accuracy of numerical results needs the actual project's inspection. However, concrete gravity dam is a large project, and the damage examples suffered strong earthquake are less, that will have a significant difficulty to evaluate an analysis method according to the limited data. Therefore, based on ANSYS computing platform, the shaking table test of simulation concrete gravity dam is simulated, and the contents include static analysis, modal analysis and the time history analysis. Due to the immature determination method of the dynamic performance of simulation concrete, the main calculational purpose is to get the dynamic elastic modulus which tallies with dam's foundation frequency through modal analysis, and the dynamic tensile strength which tallies with the measuring acceleration through time history analysis.(2) The ability of ANSYS is limited on nonlinear constitutive simulation, So it has been used for the secondary development in order to be more in line with the stress-strain relationship of concrete damage during the numerical calculation. Through the optimization of ANSYS solving process, time history calculation can adjust the elastic modulus of elements with time and the advancement of stress, that can fit with bilinear evolution model. Dynamic response of gravity model dam is analyzed with the damage calculation model established in this paper. The acceleration results are compared with measuring acceleration data in the shaking table test on each point, and then the difference ratios are given. On this basis, damage development and cracking condition of model dam are in-depth analysis under different seismic intensity, this research also provides the elements'damage development figures and compares with the measuring data from the impedance meter and the macroscopic crack, that verifies the feasibility of damage calculation method. (3) Seismic damage analysis of concrete gravity dam is to explore the stress and damage development as time promoting of existing or proposed dam with a certain intensity of .seismic waves. According to the damage calculation method mentioned above, dynamic damage situation of Kala gravity dam is analyzed in this paper. The calculated results are compared with linear analysis, and the damage status of Kala dam under design and check earthquake is given.