高堆石坝非线性强度指标坝坡稳定可靠度分析方法研究及工程应用  

RESEARCH ON METHODOLOGY OF RELIABILITY ANALYSIS OF HIGH ROCKFILL DAM SLOPE STABILITY USING NONLINEAR STRENGTH INDEXES AND ITS ENGINEERING APPLICATION

作　　者：吴震宇[1] 陈建康[1] 许唯临[1] 文斌[2] 张平[3] 

机构地区：[1]四川大学水力学与山区河流开发保护国家重点实验室,四川成都610065 [2]四川华电木里河水电开发有限公司,四川成都610016 [3]四川省农田水利局,四川成都610015

出　　处：《岩石力学与工程学报》2009年第1期130-137,共8页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金委员会、二滩水电开发有限责任公司雅砻江水电开发联合研究基金资助项目(50539060)

摘　　要：证明了按Fs-1和MR-MS两种方式构建功能函数的数学等效性,提出基于邓肯非线性强度准则、简化毕肖普法、中心差分法、一次二阶矩法及Fs-1,MR-MS两种功能函数的非线性强度指标坝坡稳定可靠度分析的新方法,探讨可靠指标β对非线性强度指标的敏感性以及非线性强度指标相关性对β和临界滑弧位置的影响,得到以下结论:(1)按Fs-1和MR-MS两种方式构建功能函数得到的β相差不超过0.5%,由于按MR-MS构建功能函数可以直接计算对随机变量的偏导数,因此,建议按此方式进行可靠度分析。(2)一次二阶矩法的β计算值相对Monte Carlo法的误差小于2%。可靠度灵敏系数反映出β随φ0的增大和Δφ的减小而增大,且β对φ0的敏感性更为显著。由此可见,φ0参数的合理确定对工程的安全和经济性至关重要。(3)φ0和Δφ的相关性对β和临界滑弧的位置影响比较明显。β随相关系数的增大而渐增,最大增幅达15.67%,同时临界滑弧的位置逐渐向坡外移动,表明不考虑相关性的计算结果偏于安全。(4)对双江口土质心墙堆石坝坝坡稳定的可靠度分析证明了所提方法的合理性,各典型工况的最小可靠指标βmin及临界滑弧的位置符合工程实际,坝坡稳定可靠度满足相应规范要求。It is first proved that the two performance functions established in terms of Fs-1 and MR-Ms are equivalent mathematically regarding definition of slope stability state. Based on the Duncan nonlinear strength mode, simplified Bishop＇s method, central difference, first-order method and the forenamed two performance functions, a new reliability analysis method of slope stability by using nonlinear strength index is presented. By discussing the sensitivity of the reliability index β to nonlinear strength indexes and the influence of correlation of nonlinear strength indexes on β and critical slip surface location, some beneficial conclusions are drawn as follows.（1） The difference of reliability indices of the two performance functions is less than 0.5%; and it is suggested that reliability analysis is implemented by way of MR-Ms, since the derivative of performance function can be computed directly. （2） The difference of reliability indices of first-order method and Monte Carlo method is less than 2%, and β increases with the increase of φ0 or redution of △φ; moreover, β is more sensitive with respect to than △φ, so it is quite important to determine the parameter of φ0 reasonably. （3） When the correlation coefficient between φ0 and △φ ovaries from 0.0 to 1.0, flincreases gradually; the maximum fluctuating percentage is 15.67%, while the critical slip surface is migrating toward the slope face; therefore, if the correlation is ignored, the analysis result would be on the safe side. （4） The reliability analysis of slope stability for the Shuangjiangkou rockfill dam shows that the method is reasonable; the mininum reliability indexes and the locations of critical slip surfaces are realistic; and the slope stability reliability meets the criteria.

关 键 词：水利工程 高堆石坝 非线性强度指标 坝坡稳定 简化毕肖普法 可靠度 相关性 

分 类 号：TV641[水利工程—水利水电工程]