【作者】 程尧平；

【导师】 张社荣；

【作者基本信息】 天津大学 ， 水工结构工程， 2008， 硕士

【摘要】 随着我国水利水电事业的蓬勃发展和混凝土重力坝技术的迅速提高,在水力资源丰富的西南和西北地区正在设计修建众多高碾压混凝土重力坝,而这些地区正是高烈度地震频发地区。在这种高烈度地震作用下,重力坝的抗震安全直接关系到下游广大地区工农业生产和人民生命财产的安全,具有特别重大的现实意义。本文以西南某水电站为例,采用三维有限元静动力分析方法,对高地震烈度下高碾压混凝土重力坝的动力特性及其抗震安全性进行了深入的研究和探讨。主要做了以下几个方面的研究工作。1.阅读国内外相关文献,综述了混凝土重力坝的发展情况,介绍了混凝土重力坝的设计理论以及抗震研究方法。2.简单介绍了地震动力方程,重力坝的有限元动力分析技术以及重力坝的抗震特性,为论文计算分析提供理论依据。3.利用大型通用有限元软件ANSYS构建了金沙江梨园水电站碾压混凝土重力坝的整体有缝三维有限元模型,计算不同工况下重力坝的应力应变,得到重力坝静力计算应力应变的一般规律。4.对梨园重力坝各坝段进行模态分析,分别计入库水和不计入库水的作用,分析大坝的各坝段的自振频率,自振周期以及结构各阶振型,对大坝自身动力特性进行深入分析。5.采用振型分解反应谱法对重力坝各坝段进行动力计算,依据规范考虑了顺河向以及竖向地震的激励作用,对计算结果进行分析对比了各坝段的动力响应,为坝体的抗震设计提供了参考,评价了大坝的抗震安全性。6.采用时程动力法对整体分缝重力坝进行动力计算,分析了坝体位移及应力随着地震荷载时间历程的变化情况,同时就应力位移变化趋势与反应谱法动力响应分析做出了对比。本论文的工作紧密结合工程实际,以具体工程为研究背景,其研究成果对设计及类似工程具有较大的参考和借鉴价值。同时,高地震烈度下混凝土重力坝的动态反应是非常复杂的问题,其动力分析中一些问题的处理还有待不断的深入研究。更多还原

【Abstract】 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.更多还原