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锦屏一级高拱坝三维渗流场及坝肩稳定性研究

Study on Three-dimension Seepage and Abutment Stability of Jinping High Arch Dam

【作者】 林正伟

【导师】 何江达;

【作者基本信息】 四川大学 , 岩土工程, 2003, 硕士

【摘要】 锦屏一级水电站位于四川省木里、盐源两县毗邻处的雅砻江中游,电站设计装机容量3300MW,采用混凝土抛物型双曲拱坝,拱坝最大坝高305m,是当今国际上拟建的最高拱坝。高拱坝坝肩岩体的稳定性是拱坝结构安全运行的基础。锦屏一级高拱坝坝址区左右坝肩存在几条规模较大的断层、深部裂缝以及岩体松驰等不利地质构造,因此,在各种工程荷载和渗流场作用下的坝肩稳定性成为拱坝设计中的重大技术问题。 本文结合锦屏一级水电工程的科研项目“锦屏一级高拱坝渗流场及整体稳定性分析”,运用三维弹塑性有限元仿真计算方法,对锦屏一级高拱坝基础三维渗流场及坝肩岩体的稳定性开展了系统的研究。其主要内容和特色在于: 1、根据锦屏一级普斯罗沟坝址地形、地质条件,建模时充分考虑左右坝肩的主要断层、深部裂缝、煌斑岩脉、节理裂隙以及岩体松弛等不利地质构造,较客观地反映工程的实际情况。 2、运用三维有限元法,分别计算不同工况下坝址区域三维渗流场的浸润线和等压线的分布特性,研究渗流对坝肩(基)稳定性的作用与影响,提出对坝肩抗滑稳定有利的防渗及排水处理方案。 3、模拟坝区岩体初始应力场。 4、运用三维弹塑性有限元法,研究天然地基情况下拱坝结构及地基的应力变位特征、采用点强度储备安全系数法和超载法分析拱坝坝肩的整体稳定性。 5、运用三维弹塑性有限元法,研究不同加固措施对拱坝结构特性以及拱坝坝肩整体稳定性的改善效果。 本文研究成果表明:防渗帷幕和排水平硐对于减少坝肩(基)浸润区范围,降低浸润线高程效果显著,可以有效改善拱坝坝肩(基)及下游边坡的整体稳定性。文中还揭示了拱坝的结构特性以及坝肩(基)可能出现破坏的部位与发四川大学硕士学位论文育深度,为拱坝的基础处理措施选择提供了依据,同时得到了天然地基方案坝肩的整体超载安全系数为3.5,加固方案的整体超载安全系数系数可以提高至4.2的重要结论。

【Abstract】 Jinping Water Power Station is located in the middle reaches of Yalong River that is adjacent to Muli and Yanyuan in Sichuan Province. The installed capacity of power station is 3300MW, and concrete vaulted dam is adopted. With a maximum dam-height of 305 meters, it is the highest arch dam to be built in the world. Abutment stability is the foundation for high arch dam running safely. On both abutments in the dam site, there are such geologic disadvantages as several large faults, deep cracks and rock slack, etc. Therefore, under the effect of project load and seepage, the abutment stability is a vital technical problem in the design of arch dam.In this thesis, integrated with a project of Jinping Water Power Station, the foundation seepage and abutment stability are studied systematically with 3D elastoplasticity finite element method. The main content and feature of the work are as follows:1, According to the topographic and geologic conditions of Pusiluogou, when the computation model being established, the unfavorable geologic structures, including the main faults, lamprophyre, deep cracks, joint fissures and rock slack lying on the left and right abutment, are fully considered. So the actual condition is simulated much objectively.2. For several different working conditions, with 3D finite element method, the distributing characteristic of saturation line and isobar at dam site are worked out respectively. The effect and influence of abutment stability under seepage are studied, the schemes for drainage disposal and seep preventing in favor of abutment stability are put forward as well.3.The initial geological stress of dam site is simulated.4. With 3D elastoplasticity finite element method, the stress and displacement of the dam and the base are studied under natural foundation condition. By way of safety coefficient methods of point strength and integral overload, the abutment stability is analyzed.5. With 3D elastoplasticity finite element method, the effects of different reinforcement measurements to abutment stability and arch dam structure are studied.It shows that impervious curtain and drainage adit are very useful in reducing the saturation area of abutment and the elevation of saturation line; the whole stability of abutment and downstream slope is improved effectively. Besides, the structure character of arch dam, the possible destructive parts and developed depth are revealed, which can provide warranty for the foundation disposal of arch dam. And an important conclusion is drawn out: the safety coefficient of integral overload under natural condition is 3.5, and it can be increased to 4.2 while layout of reinforcement being adopted.

  • 【网络出版投稿人】 四川大学
  • 【网络出版年期】2004年 01期
  • 【分类号】TV642.4
  • 【被引频次】4
  • 【下载频次】431
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