【作者】 张伟；

【导师】 张仲卿；

【作者基本信息】 广西大学 ， 水工结构工程， 2003， 硕士

【摘要】 根据导师张仲卿教授提出的三峡三期碾压混凝土拱围堰方案，本文在以往研究内容基础上，对拱围堰结构体系进行了全面、系统地计算分析。分析中采用通用三维非线性有限元软件ANSYS，从结构静力分析、稳定分析、模态分析、反应谱分析、时程分析、温度场和温度应力仿真分析等角度，对方案进行了研究，然后对结构体型进行了优化分析，使方案进一步完善。结合以往所做的研究工作，本文主要开展了以下几个方面的研究： 1．对结构在静荷载下的基本荷载组合进行应力场和位移场分析，并从结构点抗滑安全系数和抗滑稳定安全系数方面，对围堰结构体系稳定性进行研究，全面论证结构在静载下的承载性态。 2．对结构破坏机理进行研究，分析结构的水压超载破坏渐近过程和超载安全系数，进一步确定结构的安全储备。 3．对结构的模态进行分析研究，在此基础上进行了结构的反应谱分析和时程分析。反应谱分析不仅对地震效应进行单独分析研究，而且将地震效应与自重、水压、温降等静力荷载效应同时考虑，得出更加符合实际的荷载组合效应。从而全面论证结构在承受动载的性态。 4．对结构施工期和运行期全过程进行温度场和温度应力仿真分析，分析中充分考虑各种材料变化及外界条件变化。 5．建立参数化几何模型，以拱围堰体积作为目标函数，根据初方案选定几何约束条件、应力约束条件和稳定约束条件，确定优化数学模型，对结构体形进行优化分析。 6．从安全性和经济性角度，对拱围堰结构体系做出综合的、全面的评价。更多还原

【Abstract】 Based on the design proposal of the third stage RCC arch cofferdam for the Three Gorges Project, proposed by Prof Zhang Zhongqing, this paper comprehensively studied it, using three non-linear FEM methods. In the procession, static analysis, stability against sliding analysis, modal analysis, response spectrum analysis, transient dynamic analysis, temperature field and thermal stress analysis are done, and in order to make the proposal perfectly, the optimization analysis is done too. Under the research work of my tutor, the following contents are studied.1. The stress field and displacement field under basic load combination are analyzed, and Point safety against sliding and stabilization safety factor against sliding are also analyzed, so that the structural condition under static load is completely studied.2. The failure mechanism of structure is analyzed, in this way the safety factor under water press overload is acquired, so that the safety stock and the failure processing can be clearly known.3. In order to know the structural condition under dynamic load clearly, modal analysis, response spectrum analysis and transient dynamic analysis to the structure are analyzed. In the response spectrum analysis, not only the earthquake load is considered, but also other loads including gravity, water pressure and temperature drop are all considered, for acquiring the practical action of load combination.4. Considering all kinds of changes of material and environment during the whole construction, the temperature field and thermal stress are analyzed.5. The mathematic model for optimization analysis is determined by founding parametric model, selecting the volume of arch cofferdam as object function, and selecting geometric constraint conditions, stress conditions and stabilization against sliding constraint conditions. The shape optimization of the structure is then analyzed to acquire perfect proposal.6. Based on the analysis of results, the merits and demerits of the arch cofferdam are evaluated from the point of safety and economical efficiency.更多还原