| Concrete gravity dam as an important infrastructure construction in China,and the study of its dam anti-seismic problem has always been a key technical problem that must be faced and urgently needed to be solved in the construction of water conservancy and hydropower projects in China,It is also an important topic in the field of dam anti-seismic design.Numerical simulation and analysis of the dynamic response of concrete gravity dams under earthquake action is an important prerequisite for dam seismic design.Based on the ABAQUS finite element software,this paper establishes a three-dimensional finite element model of the dam,and makes the following work:(1)Using the secondary development function of ABAQUS finite element software,Independently compile subroutines for 3D additional mass units to provide a method for the rapid application of hydrodynamic pressure in the 3D finite element model.Through the numerical simulation of the actual engineering case of the KOYNA dam in India,the results of modal,dynamic displacement,dynamic stress,damage,etc.are compared with actual disaster records,the comparison of results is basically the same,it verifies the correctness and reliability of the subroutine development,and the feasibility of applying this method to solve the problem of the interaction between the structure and the hydrodynamic pressure in the 3D model.(2)The dynamic response of a typical concrete gravity dam under the action of Qian’an wave is simulated by ABAQUS finite element software,and use the dynamic time history analysis method to study the change law of the displacement field and stress field of the gravity dam under three different working conditions of full storage,half storage and empty storage.The results show that the full storage condition is the most unfavorable simulation scheme for the safety of the dam,both the maximum stress value and the maximum displacement value of the dam body increase with the increase of the height of the reservoir.In the stress field analysis,the stress concentration phenomenon mainly occurs at the downstream slope break point and the position of the dam heel,and the vertical seismic wave has a greater influence.In the analysis of the displacement field,the maximum displacement appears at the top of the dam,and the influence of the horizontal seismic wave is greater.(3)Based on the plastic damage mechanics model,the damage and failure of the KOYNA dam in India under the action of the main aftershock sequence are studied.Studies have found that aftershocks will cause serious damage accumulation and damage to the dam damaged by the main shock and cause large secondary residual deformations of the dam.Under the action of different seismic waves,the damage area of the dam after the earthquake is different,which is caused by the different damage characteristics of the main shock wave and aftershock wave,the downstream slope breaking point of the gravity dam is the weak part of the dam for earthquake resistance,but at the same time,the safety and stability of other parts cannot be ignored.The damage evolution of the gravity dam during the aftershock phase is mainly reflected in the further expansion of the damaged area in the middle and upper part of the dam body.Aftershocks have an important impact on the seismic performance of dams damaged by the main shock.Therefore,attention should be paid to earthquake sequences in the dam seismic design.(4)Analyze the intelligent detection system of concrete gravity dam.The CASTEP module in Acclerys Material Studio is used to calculate and analyze the magnetic properties of nano-material molybdenum disulfide,which provides a reference for the application of molybdenum disulfide materials in electromagnetic induction sensors.On this basis,an example is used to optimize the sensor placement in the dam. |
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