库水下降条件下土体渗流对边坡稳定性的影响研究
发布时间：2018-07-17 15:02
【摘要】：自从意大利瓦依昂水库库岸边坡垮塌的惨剧发生以后,库水位变化影响条件下的边坡稳定性的研究开始引起极大关注,目前在这一课题上已有大量的学术成果,包括实验研究与计算理论研究,就计算理论方面而言,目前研究的焦点主要集中在了强度折减法在库岸边坡稳定性的计算问题上,现已有大量文献对这一方法进行研究但仍存在一些的问题有待解决,例如,渗流场与应力场的耦合计算,强度折减法的破坏判据缺少定量化的衡量标准,对于非饱和土渗流特性对库岸边坡稳定性影响的研究较少,针对以上问题,本文进行了以下几方面的研究： 1、阐述了多孔介质中流固耦合原理。阐述了有限元强度折减法的原理,对其破坏判据进行了讨论,并针对库水位变化条件下的边坡稳定性计算提出了一种新的破坏判据,使得破坏的临界条件得以量化； 2、通过对ABAQUS通用有限元软件进行二次开发,实现了库水位随时间变化的边界条件,在此基础上建立了有库水位变化的均质土边坡模型。当认为土体非饱和区渗透系数不随含水量变化时,针对这一模型分析了当库水位以1m每天的速度下降时不同饱和渗透率对边坡内部浸润线位置以及相应安全系数的影响； 3、采用了Fredlund和Xing提出的估算方法对非饱和的土水特征曲线、以及其相应的非饱和渗透系数进行估算,并分析了该估算方法中三个参数对土水特征曲线以及非饱和土渗透系数的影响。另外,还将这一非饱和土估算方法计算得到的参数应用于库岸边坡有限元模型,实现了对库水位下降条件下非饱和非稳定渗流边坡的模拟,在此基础上分析了这三个参数对库水位下降过程中浸润面以及安全系数的影响。并通过这一分析与饱和渗透率的影响分析进行对比； 4、采用研究得到的非饱和非稳定渗流模型对沙子寨水库除险加固工程进行了有限元计算分析与设计。根据规范要求对该水库大坝的渗流稳定性和整体抗滑稳定性进行了复核,同时对规范要求的工况进行了扩展,分析水库大坝在不同降速条件下的渗流稳定性和整体抗滑稳定性。介绍了土石坝渗流加固的常用工程方法,并选择了适用于该工程的方案。对加固后的坝体建立了相应的有限元模型,并分析了其在规范要求工况下和不同水位下降速度条件下的渗流稳定性和整体抗滑稳定性。图65幅,表6个,参考文献80篇。
[Abstract]:Since the tragic collapse of the bank slope of the Wainen Reservoir in Italy, the study of slope stability under the influence of reservoir water level changes has aroused great concern. At present, a large number of academic achievements have been made on this subject. Including experimental research and computational theory research, in terms of computational theory, the focus of current research is mainly on the calculation of the stability of the slope along the bank of the reservoir by the strength reduction method. However, there are still some problems to be solved. For example, the coupling calculation of seepage field and stress field, the failure criterion of strength reduction method is lack of quantitative measurement standard. There is little research on the influence of unsaturated soil seepage characteristics on the stability of reservoir bank slope. In view of the above problems, the following aspects have been studied in this paper: 1. The principle of fluid-solid coupling in porous media is expounded. This paper expounds the principle of the finite element strength reduction method, discusses its failure criterion, and puts forward a new failure criterion for the calculation of slope stability under the condition of changing reservoir water level, which makes the critical condition of failure quantificational. 2. Through the secondary development of Abaqus universal finite element software, the boundary condition of reservoir water level changing with time is realized, and the homogeneous soil slope model with reservoir water level variation is established. When it is considered that the permeability coefficient of unsaturated soil does not change with the water content, the influence of different saturated permeability on the position of the slope internal infiltration line and the corresponding safety factor is analyzed when the reservoir water level drops at a speed of 1m per day. 3. Using Fredlund and Xing's estimation method, the unsaturated soil water characteristic curve and its corresponding unsaturated permeability coefficient are estimated. The influence of three parameters on soil water characteristic curve and permeability coefficient of unsaturated soil is analyzed. In addition, the parameters obtained by the estimation method of unsaturated soil are applied to the finite element model of reservoir bank slope, and the simulation of unsaturated seepage slope under the condition of falling reservoir water level is realized. On this basis, the influence of these three parameters on the infiltration surface and safety factor of the reservoir water level is analyzed. This analysis is compared with the analysis of the effect of saturated permeability. (4) finite element analysis and design are carried out for the reinforcement project of Shazhai reservoir by using the unsaturated unsteady seepage model. According to the requirements of the code, the seepage stability and the overall anti-slide stability of the dam are reviewed, and the working conditions required by the code are extended to analyze the seepage stability and the overall anti-slide stability of the reservoir dam under different speed reduction conditions. This paper introduces the common engineering methods for seepage reinforcement of earth-rock dams, and selects the scheme suitable for this project. The finite element model of the strengthened dam is established, and the seepage stability and the overall anti-slide stability of the dam are analyzed under the condition of the code requirement and the different water level falling velocity. There are 65 pictures, 6 tables and 80 references.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV223.4
本文编号：2130024
[Abstract]:Since the tragic collapse of the bank slope of the Wainen Reservoir in Italy, the study of slope stability under the influence of reservoir water level changes has aroused great concern. At present, a large number of academic achievements have been made on this subject. Including experimental research and computational theory research, in terms of computational theory, the focus of current research is mainly on the calculation of the stability of the slope along the bank of the reservoir by the strength reduction method. However, there are still some problems to be solved. For example, the coupling calculation of seepage field and stress field, the failure criterion of strength reduction method is lack of quantitative measurement standard. There is little research on the influence of unsaturated soil seepage characteristics on the stability of reservoir bank slope. In view of the above problems, the following aspects have been studied in this paper: 1. The principle of fluid-solid coupling in porous media is expounded. This paper expounds the principle of the finite element strength reduction method, discusses its failure criterion, and puts forward a new failure criterion for the calculation of slope stability under the condition of changing reservoir water level, which makes the critical condition of failure quantificational. 2. Through the secondary development of Abaqus universal finite element software, the boundary condition of reservoir water level changing with time is realized, and the homogeneous soil slope model with reservoir water level variation is established. When it is considered that the permeability coefficient of unsaturated soil does not change with the water content, the influence of different saturated permeability on the position of the slope internal infiltration line and the corresponding safety factor is analyzed when the reservoir water level drops at a speed of 1m per day. 3. Using Fredlund and Xing's estimation method, the unsaturated soil water characteristic curve and its corresponding unsaturated permeability coefficient are estimated. The influence of three parameters on soil water characteristic curve and permeability coefficient of unsaturated soil is analyzed. In addition, the parameters obtained by the estimation method of unsaturated soil are applied to the finite element model of reservoir bank slope, and the simulation of unsaturated seepage slope under the condition of falling reservoir water level is realized. On this basis, the influence of these three parameters on the infiltration surface and safety factor of the reservoir water level is analyzed. This analysis is compared with the analysis of the effect of saturated permeability. (4) finite element analysis and design are carried out for the reinforcement project of Shazhai reservoir by using the unsaturated unsteady seepage model. According to the requirements of the code, the seepage stability and the overall anti-slide stability of the dam are reviewed, and the working conditions required by the code are extended to analyze the seepage stability and the overall anti-slide stability of the reservoir dam under different speed reduction conditions. This paper introduces the common engineering methods for seepage reinforcement of earth-rock dams, and selects the scheme suitable for this project. The finite element model of the strengthened dam is established, and the seepage stability and the overall anti-slide stability of the dam are analyzed under the condition of the code requirement and the different water level falling velocity. There are 65 pictures, 6 tables and 80 references.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV223.4
【参考文献】
相关期刊论文 前10条
1 谭文辉,蔡美峰,周汝弟;节理边坡渗流离散元模拟及边坡可靠性分析[J];北京科技大学学报;2003年04期
2 刘红岩;王新生;秦四清;阮浩;;岩石边坡裂隙渗流的流形元模拟[J];工程地质学报;2008年01期
3 邓东平;李亮;赵炼恒;;稳定渗流条件下土坡稳定性分析的一种新方法[J];工程地质学报;2011年01期
4 时卫民;郑颖人;;库水位下降情况下滑坡的稳定性评价[J];工程勘察;2004年01期
5 徐东强,姜芳禄,赵晓艳,黄竞;渗流作用下边坡最危险圆弧滑面的优化解[J];工程力学;2005年05期
6 沈振中;姜媛媛;王金男;;非稳定渗流作用的岩体边坡稳定非连续变形分析[J];河海大学学报(自然科学版);2007年01期
7 邓宏艳;王成华;;非线性组合模型在库岸边坡地下水位预测中的应用[J];土木建筑与环境工程;2010年01期
8 郝飞;任光明;蒋权翔;;库水位变化对某电站库岸边坡稳定性的影响[J];山西建筑;2008年33期
9 李爱兵;边坡中地下水渗流的边界元分析[J];矿业研究与开发;1994年01期
10 张云;;露天矿边坡岩体裂隙含水介质渗流场边界元分析[J];南京大学学报(自然科学版);1992年01期
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