【作者】 章杭惠；

【导师】 李同春；

【作者基本信息】 河海大学 ， 水工结构工程， 2003， 硕士

【摘要】 水工混凝土建筑物随着使用年限的增长不断老化并产生各种病危险是一个世界性问题。本文主要针对目前病险坝中存在的常见问题，坝肩稳定和坝体裂缝，并且结合河海大学水工结构研究所和国家电力公司成都勘测设计研究院的合作项目—双河水库混凝土拱坝病险及加固仿真分析，在这两方面做了一些初步的研究。 拱坝在施工期和运行期经常会出现裂缝。对于裂缝位置已知的情况下，本文从应力复核和仿真分析两个角度探讨了裂缝产生和发展的原因。在综合有限元和多拱梁法优点的基础上，提出了一种改进的拱坝等效应力分析方法，并通过算例探讨了网格尺寸对拱坝等效应力的影响。此外，本文提出了在坝体已知裂缝处设置接触面单元(或薄层单元)，来近似模拟裂缝的发生和发展过程，并对双河拱坝蓄水前后进行了应力场、温度场的仿真分析。针对计算模型中坝基材料复杂的特点，提出了坝基用空间四面体单元离散，坝体用空间六面体单元离散的非一致网格协调位移解法，用于求解拱坝坝体和坝肩的相互作用。 此外，本文在前人研究的常规坝肩稳定分析方法的基础上，提出了非线性有限元迭代解法，并应用于双河拱坝坝肩稳定分析。该方法可以较精确地模拟考虑地基中的软弱夹层、断层、裂隙等地质情况，并且能反映各种材料(主要是软弱面)在受荷后的非线性性质及屈服、破坏规律，可以计及各种复杂荷载如自重、渗压及地震等荷载。 对双河拱坝的病险机理研究及分析表明：(1)温降是造成坝体裂缝开展的主要外因；(2)软硬相间的地基条件是导致坝体裂缝的主要内因；(3)双河拱坝抗力体山体单薄，坝肩的稳定安全度均比较低。在此基础上成勘院提出了相应的组合加固除险措施，文中对加固后的双河拱坝进行了坝肩抗滑安全度和应力控制指标的复核，结果表明该组合加固措施是合理、可行的。更多还原

【Abstract】 With the increase of the service period, the problem, gradually aging and various dangerous sick of hydraulic engineering concrete constructions, becomes an international one step by step. As for the common problems in the sick-dangerous dam recently, abutment stability and dam bodycracks, some primary research are given in the paper, combined with the project------Study on theEmulation Analysis of Danger Removing and Reinforcement on the Sick-dangerous Concrete Arch Dams of Shuanghe, which is cooperated between Hydraulic Structure Center of Hohai University and Chendu Hydroelectric Investigation & Design Institute of SPC.Usually, there are some cracks in arch dam during construction period and operating period. In this paper, only those existing cracks and their growing are discussed. The analysis is described in two ways, stress checking and emulation analysis. Based on the marriage of finite elements method and multi-arch beam method, improving equivalent stress analysis method of arch dam is proposed and the effect of mesh size on arch dam equivalent stress is discussed in this paper. Furthermore, another new method is given in this paper that contact elements (or thin-layer elements) are located in the position of existing crack of arch dam to simulate approximately the process of cracks producing and growing. And the emulation analysis of stress and temperature fields of Shuanghe arch dam is carried out in the reservoir-empty condition and in the full-reservoir condition with this method mentioned above. On the other hand, considering characteristic of complex material of dam foundation in computation model, compatible displacement method of incompatible mesh is presented in this paper, which describes the interaction conveniently between arch dam body and dam abutment. Therefore, the mesh of dam body may be generated by 3D hexahedron elements and that of dam foundation may be generated by 3D tetrahedron elements.Moreover, based on routine research method on abutment stability, non-linear finite element iteration method is put forward in this paper, which is applied in the analysis of abutment stability of Shuanghe arch dam successfully at the same time. This method can simulate accurately soft stratums, faults and cracks in foundation, reflect the non-linear characteristics of all kinds of materials (for weak surface mainly) and yield criterion and destroy rule under the load, and take various complicated load into account such as self-weight, seepage pressure and seismic force etc.Trough the analysis of sick-dangerous mechanism on Shuanghe arch dam, some conclusions are obtained in the following: (1) Temperature drop is the main external cause of crack growing; (2) Foundation condition with soft and hard interphase is the important internal reason resulting in crack producing; (3) For the resistance and mountain body of Shuanghe arch dam is thin and weak, safety factor of abutment stability is low. On the basis of the analysis mentioned above, Chendu Hydroelectric Investigation & Design Institute of SPC advances corresponding combinatorial reinforcement and danger removing measures. Safety factor of abutment stability and stress analysis of Shuanghe arch dam strengthened are checked in this paper, and the results prove that these measures are reasonable and feasible.更多还原