深厚覆盖层高土石围堰堰坡稳定研究

发布时间：2018-01-11 13:30

本文关键词：深厚覆盖层高土石围堰堰坡稳定研究　出处：《三峡大学》2015年硕士论文　论文类型：学位论文

【摘要】：围堰是导流工程中用来围护基坑，保证水工建筑物能在干地施工的临时挡水建筑物，其布局和施工程序对工程施工格局起决定作用，，并对工程总进度和工程质量有重要影响。围堰的安全至关重要，不仅关系到整个施工导流工程和主体工程的安全和进度，甚至涉及下游的安全问题。近年来，随着水利水电工程建设的重心进一步向西南地区转移，深厚覆盖层的问题越来越突出，围堰的施工运行管理难度更大。本文以某深厚覆盖层土石围堰为研究对象，在渗流分析的基础上对围堰堰坡稳定进行了研究。主要工作内容如下：（1）介绍了渗流计算和边坡稳定计算的基本原理和方法，基于非线性粗粒料的抗剪强度理论和一种新的堰坡最危险滑弧搜索法，编制了一套考虑非线性抗剪强度堰坡稳定性分析程序。（2）模拟了围堰施工及运行阶段：戗堤截流、基坑抽水、基坑开挖、上游退水等过程围堰渗流场变化及对各阶段围堰堰坡进行了抗滑稳定分析。（3）计算分析围堰基坑抽水速度、基坑开挖速度、上游退水速度、覆盖层渗透特性及防渗墙不同程度不同形式局部破损等影响因素对围堰渗流的影响，从浸润线溢流出口比降、单宽流量、防渗墙所受最大比降等指标得出了相应的结论。（4）在渗流分析的基础上，利用非线性抗剪强度堰坡稳定性分析程序对围堰堰坡的各种工况进行稳定性计算，得出堰坡最危险滑弧及最小安全系数。考虑影响渗流的几个影响因子，对围堰堰坡进行稳定分析，通过抗滑稳定最小安全系数得出了相应结论。
[Abstract]:Cofferdam is a temporary water retaining structure which is used in diversion engineering to protect foundation pit and ensure hydraulic structure can be constructed on dry land. Its layout and construction procedure play a decisive role in the construction pattern of the project. The safety of cofferdam is very important, which not only relates to the safety and progress of the whole construction diversion project and the main project, but also involves the safety problems of downstream in recent years. As the center of gravity of water conservancy and hydropower projects is further shifted to the southwest, the problem of deep overburden becomes more and more prominent. The construction management of cofferdam is more difficult. In this paper, the stability of cofferdam slope is studied on the basis of seepage analysis, taking a deep overburden earth-rock cofferdam as research object. The main work is as follows: 1) the basic principles and methods of seepage calculation and slope stability calculation are introduced, based on the shear strength theory of nonlinear coarse granular materials and a new method of the most dangerous sliding arc search for Weir slope. A program for stability analysis of Weir slope considering nonlinear shear strength is developed. 2) the seepage field changes of cofferdam are simulated during the construction and operation stage of cofferdam, such as closure of embankment, pumping of foundation pit, excavation of foundation pit and upstream receding water, and the stability analysis of anti-slide of cofferdam slope in each stage is carried out. 3) the influence factors on cofferdam seepage are calculated and analyzed, such as pumping speed of cofferdam foundation pit, excavation speed of foundation pit, upstream retreating speed, permeation characteristic of overburden and local damage of impervious wall in different degree. The corresponding conclusions are obtained from the ratio drop of the overflow outlet, the single wide flow rate, and the maximum ratio drop of the impervious wall. 4) on the basis of seepage analysis, the stability of cofferdam slope is calculated by using nonlinear shear strength Weir slope stability analysis program. The most dangerous sliding arc and minimum safety factor of Weir slope are obtained. Considering several influence factors affecting seepage flow, the stability of cofferdam slope is analyzed, and the corresponding conclusion is drawn through the minimum safety factor of anti-slide stability.
【学位授予单位】：三峡大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TV551.31;TV223

【参考文献】