【作者】 王健；

【导师】 梁力；

【作者基本信息】 东北大学 ， 工程力学， 2011， 硕士

【摘要】 本文以参窝水库溢流坝闸墩为研究对象,利用ANSYS软件,建立闸墩三维整体式有限元模型和组合式有限元模型。将静水推力荷载、闸墩上部荷载、闸门开启时的推力荷载、闸墩自重及温度荷载组合成几种计算工况,分别对闸墩整体结构及裂缝位置应力分布情况进行线性静力计算分析,再以材料力学第一强度理论为理论基础,确定闸墩裂缝的主要成因是闸门开启至最大位置时的推力荷载。并参照闸墩实际裂缝情况,对比两种模型计算结果的相同点和不同点,分析两种模型计算的准确性。同时对已开裂的现有闸墩结构进行线性计算分析,利用ANSYS中的单元生死技术杀死裂缝处的混凝土单元,实现对混凝土已破坏、钢筋保持原有形式继续工作状态的模拟,对现有裂缝闸墩的安全性进行分析,并判断裂缝的扩展趋势,确定闸墩加固的必要性。最后,在对闸墩裂缝存在状态分析的基础上,提出闸墩加固方案,即选用SCC自密实混凝土灌浆嵌缝、体外粘贴CFRP碳纤维网格布的方法,并对加固后的闸墩结构进行了线性静力分析。结果表明,加固后的闸墩整体结构达到稳定要求,原有裂缝不会再继续扩展。计算结果表明,采用线性静力计算分析闸墩裂缝成因及加固措施可行性是一种有效的方法,其计算结果可靠,对大坝安全运行具有重要意义,且具备相似工程的参考价值。更多还原

【Abstract】 In this paper, two finite element models described as integral model and combined model are proposed using the finite element software ANSYS, to study the structural behaviors of spillway pier of Shen Wo dam. Linear static solution is conducted under several working conditions, which are achieved by different combination of hydrostatic thrust load, pier upper load, pier thrust load when opening, pier weight and temperature load. Then stress distribution of the integral pier and crack location is analyzed respectively by extracting and observing in detail the numerical results. Based on the first strength theory in mechanics of materials, the analyses results indicate that the thrust load when the gate opened up to the maximum angle is the main reason contributing to concrete crack. Comparisons between integral model and combined model have been conducted to highlight the similarities and differences, and both of the models are verified to be accurate after the validation against the actual crack location distribution on pier.Using the validated cracking models, a new lineal solution is conducted for which the "birth and death" technique of ANSYS is used to kill the concrete elements in crack location, so as to simulate the actual working condition when concrete has failed but steel there retains. The results obtained capture well the crack development trend and provide insight into security analysis of the cracking pier, as well as emphasize the need for pier reinforcement.Finally, with the incorporation of grouting and caulking in the crack location using SCC self-compacting concrete, and external bond of CFRP carbon fiber mesh, a pier reinforcement proposal is presented, then lineal static solution is conducted about the reinforced pier model. The numerical results indicate that integral reinforced pier structure can meet stability requirements and the original crack will not develop. The results show that the linear static analysis of crack and reinforcement measures pier feasibility is an effective method, the calculation results are reliable and important for the safe operation of the dam, and have similar reference works.更多还原