第36卷第5期 岩 土 力 学 Vol.36 No.5 2015年5月 Rock and Soil Mechanics May 2015

DOI：10.16285/j.rsm.2015.05.030

基于离散元的重力坝多滑面深层抗滑稳定分析

杨利福1, 2，常晓林1, 2，周 伟1, 2，程勇刚1, 2，马 刚1, 2

（1.武汉大学 水资源与水电工程科学国家重点实验室，湖北 武汉 430072；2.武汉大学 水工岩石力学教育部重点实验室，湖北 武汉 430072）

摘 要：重力坝的深层抗滑稳定分析多采用刚体极限平衡法和非线性有限元法，但刚体极限平衡法不能反映坝基岩体渐进失稳过程和破坏的力学机制，非线性有限元法模拟岩体不连续效率低，且还未有统一的失稳判据。基于离散块体边界应力计算结果，提出重力坝坝基多滑面抗滑稳定安全系数计算公式，并探讨了以坝体-坝基系统能量突变作为坝基失稳判据的物理意义。通过与非线性有限单元法、刚体极限平衡法计算结果的比较，验证了所提方法及判据的可靠性及合理性。结合向家坝水电站重力坝泄12#坝段进行计算分析，结果表明：基于离散元强度储备系数法搜索的坝基失稳通道由坝基岩体屈服区和结构面滑移带组成，所提计算方法与判据适用于实际工程的坝基深层抗滑稳定计算分析，且计算结果偏安全。 关 键 词：离散元；重力坝；多滑面；安全系数；失稳判据；能量突变

中图分类号：TU 457 文献识别码：A 文章编号：1000－7598 (2015) 05－1463－09

Deep anti-sliding stability analysis of gravity dam with multiple

sliding planes based on distinct element method

YANG Li-fu, CHANG Xiao-lin, ZHOU Wei1, 2, CHENG Yong-gang1, 2, MA Gang1, 2

(1. State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, Hubei 430072, China; 2. Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering of Education Ministry, Wuhan University, Wuhan, Hubei 430072, China)

1, 21, 2

Abstract: Although the limit equilibrium method for rigid bodies and the nonlinear finite element method are commonly used to analyze the deep anti-sliding stability of gravity dams, the limit equilibrium method does not capture the feature of progressive failure of gravity dam, and the nonlinear finite element method cannot effectively simulate the behavior of discontinuous rock masses. In addition, a unified failure criterion has yet to be developed for the finite element analysis. Using the calculated boundary stresses based on the discrete block method, a formulation is derived for calculating the factor of safety with regard to the deep anti-sliding stability of gravity dams with multiple sliding planes, and the physical meaning of the dam foundation failure criterion based on the energy mutation of the dam-foundation system is clarified. By comparing the calculated results of the finite element method and the limit equilibrium method, the proposed method and criterion are validated. A case study is performed on the 12th section of Xiangjiaba Gravity Dam, and the results indicate that the instability zone of dam foundation is composed of a yield zone of rock mass foundation and a sliding zone of structural planes. This implies that the proposed method and criterion is capable of addressing the deep anti-sliding stability of gravity dams, and yielding a reasonable factor of safety for dam design.

Keywords: distinct element method; gravity dam; multiple sliding surfaces; safety factor; failure criterion; energy mutation

1 引 言

[1]

《混凝土重力坝设计规范》（DL 5108－1999）和（SL 319－2005）[2]规定：当坝基岩体内存在软

方法和非线性有限元法。

刚体极限平衡法因其概念清晰、简单实用且积累了丰富的工程经验而被规范推荐使用，但规范规定只适用于单滑面和双滑面情况，且计算过程要假定块体条间力倾角，而安全系数受该倾角的影响较大。为此，陈祖煜等[3]提出重力坝深层抗滑稳定SARMA法；陈际唐等[4]改进了坝基深层抗滑稳定

弱结构面缓倾角裂隙及坝下游经冲刷形成临空面等情况时需核算深层抗滑稳定，并有必要的安全储备。重力坝的深层抗滑稳定分析采用刚体极限平衡分析

收稿日期：2013-12-26

基金项目：国家自然科学基金资助项目（No. 51179139）。

第一作者简介：杨利福，男，1987年生，博士研究生，主要从事高坝结构数值仿真方面的研究工作。E-mail: yanglifu0598@163.com 通讯作者：周伟，男，1975年生，教授，博士生导师，主要从事高坝结构数值仿真方面的教学与研究。E-mail: zw_mxx@163.com