某混凝土重力坝地震动响应及敏感性研究

发布时间：2018-08-23 08:12

【摘要】：我国的水利工程对于国家经济和政治以及人民的生活有着十分重要的影响,然而我国有许多地区处于地震带,工程一旦失事将带来灾难性后果,因此保证水工建筑物在地震中的使用安全是迫在眉睫的。针对这个问题,本文结合龙滩大坝工程实例对重力坝进行有限元抗震分析,为今后重力坝的抗震性能研究提供相关的参考信息。本文结合水工建筑物的相关设计方法,利用有限元ANSYS分析软件建立了重力坝处于空库、死水位以及校核洪水位这三种工况下的模型,并且考虑库水-大坝的流固耦合作用,对重力坝进行地震动响应分析。通过分析得到的相关数据与云图等,分析重力坝在地震作用下的薄弱部位和不同水位下的坝体响应。其次,为了分析在地震同时又出现较大风浪情况的重力坝的响应问题,本文考虑波浪荷载的作用,对校核洪水位工况下的模型进行地震动响应分析。同时,对比没有考虑波浪荷载但同样处于校核洪水位工况的模型分析结果,分析波浪力对重力坝的影响。此外,由于重力坝所处的环境不一样,则受到的外力作用也不一样,对坝体材料混凝土性能的要求也不尽相同。坝址地震烈度越大则地震作用越强,动水压力也就越大;所处地区风区速度不一样则引起的风浪大小不同,则坝体所受的波浪荷载也不一样。坝体主要的破坏形式为混凝土受拉破坏,而受拉性能主要由材料的力学参数控制。本文利用ANSYS中APDL语言编写了三维模型分析程序,基于混凝土塑性损伤本构对重力坝进行有限元分析,并通过改变混凝土的弹模和受拉强度来改变它的受拉塑性损伤本构曲线,建立不同本构曲线下的模型进行有限元分析,分析混凝土对大坝地震响应的敏感性。
[Abstract]:China's water conservancy projects have a very important impact on the country's economy and politics as well as people's lives. However, many areas in China are located in the earthquake zone. Once the project is wrecked, it will bring disastrous consequences. Therefore, it is urgent to ensure the safety of hydraulic structures in the earthquake. In view of this problem, this paper combines Longtan Dam. The finite element aseismic analysis of gravity dams is carried out by an engineering example to provide relevant reference information for the future research on the aseismic performance of gravity dams. Combining with the relevant design methods of hydraulic structures, this paper establishes the models of gravity dams under three working conditions: empty reservoir, dead water level and checking flood level by using the finite element ANSYS analysis software. Considering the fluid-structure interaction between reservoir water and dam, the seismic response of gravity dam is analyzed. The weak position of gravity dam under earthquake and the response of gravity dam under different water levels are analyzed by analyzing the related data and cloud pictures. Considering the action of wave load, the seismic response of the model under the condition of checking flood level is analyzed. Meanwhile, the influence of wave force on the gravity dam is analyzed by comparing the results of the model analysis under the condition of checking flood level without considering wave load. The greater the seismic intensity of the dam site, the stronger the seismic action and the greater the hydrodynamic pressure; the different wind speed in the region will cause different wind waves, and the wave loads on the dam body will be different. The tensile properties are mainly controlled by the mechanical parameters of the material. In this paper, a three-dimensional model analysis program is compiled by using the APDL language of ANSYS. Based on the plastic damage constitutive model of concrete, the finite element analysis of gravity dam is carried out. By changing the elastic modulus and tensile strength of concrete, the tensile plastic damage constitutive curve is changed, and different constitutive curves are established. The sensitivity of concrete to the seismic response of the dam is analyzed by finite element analysis.
【学位授予单位】：广州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV312;TV642.3

【参考文献】