【作者】 陈刚；

【导师】 张林；

【作者基本信息】 四川大学 ， 水工结构工程， 2001， 硕士

【摘要】 沙牌碾压混凝土拱坝是目前世界上在建的最高碾压混凝土拱坝，最大坝高132m。为了使工程优质、快速建成，同时推动我国碾压混凝土筑坝技术的发展，它被列入国家“九五”重点科技攻关项目。在此期间对工程中面临的一系列关键技术问题，如设计理论、计算方法、结构设计、材料选择和施工工艺等进行深入研究。特别是在结构设计中，大坝采用了两条诱导缝加两条横缝的分缝方案，以诱导坝体裂缝在预想部位发生，并进行灌浆处理，从而限制拱坝开裂部位及裂缝扩展，确保大坝安全运行。但是设缝后，坝体的开裂是否会在预想部位发生，诱导缝开裂失效的可靠性如何，以及坝体可能出现的破坏形态和破坏机制是工程设计中需要研究和解决的关键问题。 本论文结合国家“九五”科技攻关项目，应用断裂力学、数理统计、优化分析以及神经网络等基本理论，采用三维物理模型试验和随机可靠度分析方法对沙牌碾压混凝土高拱坝进行了材料性能试验、结构可靠度分析和坝体的开裂与破坏机制研究。 首先进行了碾压混凝土的断裂性能试验，获得了碾压混凝土的断裂韧度、断裂能等力学指标，为计算分析和试验研究提供了基础资料；在结构可靠度研究中，探索了一种基于人工神经网络的拱坝可靠度分析方法，对拱坝坝体及诱导缝进行了可靠度分析，获得了各结点的可靠性指标β，揭示了坝体及诱导缝开裂失效的概率，最易开裂的部位；在三维整体结构模型破坏试验中， 四）【I人学硕十学位论文建立了原、模型诱导缝开裂相似条件，进行了诱导缝的开裂相似模拟，获得了拱坝的应力与变形分布特性，揭示了拱坝超载破坏的发展过程、破坏形态和破坏机理。 论文从不同的角度，采用不同的分析方法，相互验证，互为补充。特别是从随机力学的角度分析了沙牌拱坝的可靠度，进一步完善了攻关期间对沙牌拱坝结构特性的研究。为拱坝的可靠度分析探索了一种易于编程及处理的简单适用方法。更多还原

【Abstract】 ShaPai RCC arch dam is the newly highest RCC arch darn on the earth. It is I 32m high. In order to not only complete the engineering rapidly and high-quality but also accelerate RCC technique, the engineering was determined the country tackling project in inth-Five-Year Plan? The key problem such as design theory, calculating method, material selection and construction technique had been researched during last five years. Especially structure adopts two induced joints and two transverse joints in order to prevent the darn from producing irregular cracks, induce the cracks to produce in expected position. Following grouting on them to assure the stability of the dam. However, the cracks occur in expected position or not, how much probability is the induced cracks craze, and the security and the probable counterworking mechanism of the dam are all key technical problems in engineering design.Combined with the country’s tackling project Shapai RCC arch dam in ~Ninth-Five-Year Plan? the paper analyzes the ShaPai RCC arch dam in detail by 3-D mechanics model test and stochastic reliability analysis. Advanced solar theory, optimization theory, fracture mechanics theory and ANN method is applied to the analysis of the arch dam. Material property is tested for the following work.At first, RCC rupture strength and fracture coefficient is acquired by RCC fracture test, which provides basal datum for following calculation and model test. A method based on artificial neural network method for analyzing arch dam’s structuralprobability is recommended among the structural reliability research. Calculating and analyzing provide the lapse probability of the dam and the induced joints and the easiest lapse section. 3D model test establishes cracking analogy requirement between prototype and model simulates the induced joints by applying fracture principle and shows the stress distribution and strain distribution of the arch dam. Moreover model test demonstrates the destruct course, the destruct shape and the destruct mechanism of the overloading dani.Different points of view and methods validate each other and complement each other in the paper. Especially stochastic reliability analysis of Shapai arch dam complements the research for the RCC dam structure in?Ninth-Five-Year Plan? An easy-programmed random analysis method is recommended for probability calculation of arch dam.更多还原