Research Of Dynamic Fracture Of Dam Of Reservoir Water-Dam-Foundation System

In recent years,China's economic aggregate,technological level and scientific theory have been developed rapidly.In order to alleviate the shortage of energy resources in China,a series of large dams have been built,such as the Three Gorges Dam,the Ertan dam and the Danjiangkou water control project.Under normal storage,these large dams can meet the normal needs.However,China's natural climate is abnormal in recent years with some serious natural disasters like floods and earthquakes occur frequently.Under the above cases,the destruction of these large water conservancy projects will cause huge threats to downstream ecological environment and the safety of people's lives and property.Therefore,it is of great significant to study the destruction process and failure modes of the reservoir water-dam-infinite foundation system under seismic loading.Based on the extended finite element method,the basic principles of the additional mass method and the infinite element method,combining with actual situation with ABAQUS,MATLAB,and FROTRAN compilers.The following research is conducted.Based on the extended finite element theory,the cracking process of the neck and heel of gravity dam under water overloading is simulated.In the process of calculation,the overload of water level is regarded as static overloading.The crack path and the initial crack angle are obtained by considering the effects of different water pressure distribution in crackle on the process of cracking.The calculation results show that different water pressure distribution in cracks has a relatively small influence on the cracking of neck of gravity dam,but has a greater influence on the heel of the gravity dam and the initial crack angle of the uniform water pressure model in the cracks is the largest.The dynamic cracking process of cracks in dam neck,initial crack of dam heel and primary and secondary crack are studied.The development rules of cracks including crack extension path,the crack of a single dam neck,the crack of the dam heel and the primary and secondary cracks are obtained by setting dam heel cracks with different lengths.The cracking process of the neck and heel of gravity dam and primary and secondary crack based on reservoir water-dam-infinite foundation system is simulated.The influence of infinite foundation on the cracking of gravity dam is studied by using massless foundation model and semi infinite foundation model,then the cracking paths of the dam in the reservoir water-dam-infinite foundation system under different initial cracks are obtained,and the destruction modes and crack extension law of gravity dam in dam system are also obtained.Comparing with the single dam model,it is found that the cracking degree of mode considering the function of infinite foundation and relative displacement of the dam top are obviously decreased and the seismic response of the semi infinite foundation model is less than that of the massless foundation model.