Research On The Global Anti-seismic Safety Of Concrete Gravity Dam

With the rapid development of water conservation and RCC dam technology, some high RCC gravity dams will be constructed in southwest and northwest regions where exist not only plentiful water resources but also frequent earthquake. It is endanger the industrial and agricultural production, the safety of people's life and property in the large regions of downstream under the high intensity seismic action, so more research on anti-seismic safety is very significant. Based on an hydro-power station in southwest region, this paper use the method of static and dynamic 3D finite element analysis in order to study deeply the dynamical characteristics and anti-seismic safety of high RCC gravity dam in high earthquake intensity. The main works of this paper are as follows:1.According to reading the domestic and international literatures, summarized the development actuality of concrete gravity dam, introduced the design theory of the concrete gravity dam and the main method in seismic study.2.To provide the theory for this paper, introduced the dynamical equation of seismic,the method of finite element analysis in gravity dam and the anti-seismic characteristics of gravity dam.3.By using finite element software ANSYS, based on the Liyuan hydro-power station in Jinshajing, the holistic 3D finite element simulation model of the RCC gravity dam with transverse joint was built, to calculate the stress and displacement of structure under several different working conditions, and gain the distribution laws of the statics calculation of gravity dam.4.Through modal analysis of all monolith in two conditons:counting the reservior water's effect or not, the self-vibration frequency, self-vibration period and the structure's all mode shapes were calculated, the dynamical characteristics was deeply analysised.5.Considering the effect of seismic in both two directions according to the criterion, all monolith were calculated by using spectrum method, the dynamical respond of all monolith by the results were compared, to provide some reference for the gravity dam's anti-seismic design, and appraise the safety of gravity dam's anti-seismic.6.Calculated the model by transient analysis method, the changes of the displacement and stress in the process of seismical loads were analysised, also the results of transient analysis method were compared with the results of seismic respond action by using spectrum method.All work of this paper is combined with the practical project and the research conclusion provide the practical reference to the design and similar projects. At the same time, dynamic response of the high RCC gravity dam is very complex in high earthquake intensity, the problems for further research are pointed out in dynamic analysis.