Hoek–Brown(HB)strength criterion can reflect rock’s inherent failure nature,so it is more suitable for analyzing the stability of rock slopes.However,the traditional limit equilibrium methods are at present only sui...Hoek–Brown(HB)strength criterion can reflect rock’s inherent failure nature,so it is more suitable for analyzing the stability of rock slopes.However,the traditional limit equilibrium methods are at present only suitable for analyzing the rock slope stability using the linear equivalent Mohr–Coulomb(EMC)strength parameters instead of the nonlinear HB strength criterion.Therefore,a new method derived to analyze directly the rock slope stability using the nonlinear HB strength criterion for arbitrary curve slip surface was described in the limit equilibrium framework.The current method was established based on certain assumptions concerning the stresses on the slip surface through amending the initial normal stressσ0 obtained without considering the effect of inter-slice forces,and it can satisfy all static equilibrium conditions of the sliding body,so the current method can obtain the reasonable and strict factor of safety(FOS)solutions.Compared with the results of other methods in some examples,the feasibility of the current method was verified.Meanwhile,the parametric analysis shows that the slope angleβhas an important influence on the difference of the results obtained using the nonlinear HB strength criterion and its linear EMC strength parameters.Forβ≤45°,both of the results are similar,showing the traditional limit equilibrium methods using the linear EMC strength parameters and the current method are all suitable to analyze rock slope stability,but forβ>60°,the differences of both the results are obvious,showing the actual slope stability state can not be reflected in the traditional limit equilibrium methods,and then the current method should be used.展开更多
在有限元极限分析(finite element limit analysis, FELA)的基础上,结合随机场理论,提出了网格自适应的边坡可靠性随机有限元极限分析方法,探讨了网格自适应前后的FELA法的确定性和可靠性分析结果,重点针对网格自适应FELA方法,从安全系...在有限元极限分析(finite element limit analysis, FELA)的基础上,结合随机场理论,提出了网格自适应的边坡可靠性随机有限元极限分析方法,探讨了网格自适应前后的FELA法的确定性和可靠性分析结果,重点针对网格自适应FELA方法,从安全系数均值、分布规律及可靠度指标、潜在滑移面分布等角度分析了岩土参数变异系数和波动范围的影响.结果表明:考虑网格自适应的FELA能有效搜索潜在滑移面,在获得严格上、下限解的同时可显著提高边坡可靠性分析效率;通过随机场刻画参数变异特性能降低传统确定性分析对边坡稳定性的过高估计.随着变异系数的增大,安全系数概率密度曲线整体向左偏移,安全系数均值下降但变异性增大,坡体可靠度指标减小,坡体潜在滑面的分布更为离散;随着波动范围增大,出现了坡体安全系数均值增大但可靠性指标减小的互斥现象.相比黏聚力变异系数和水平波动范围,边坡可靠性分析结果对内摩擦角变异系数和竖向波动范围更为敏感.展开更多
基金Project(2015M580702)supported by China Postdoctoral Science FoundationProject(51608541)supported by the National Natural Science Foundation of ChinaProject(2014122066)supported by the Guizhou Provincial Department of Transportation Foundation,China
文摘Hoek–Brown(HB)strength criterion can reflect rock’s inherent failure nature,so it is more suitable for analyzing the stability of rock slopes.However,the traditional limit equilibrium methods are at present only suitable for analyzing the rock slope stability using the linear equivalent Mohr–Coulomb(EMC)strength parameters instead of the nonlinear HB strength criterion.Therefore,a new method derived to analyze directly the rock slope stability using the nonlinear HB strength criterion for arbitrary curve slip surface was described in the limit equilibrium framework.The current method was established based on certain assumptions concerning the stresses on the slip surface through amending the initial normal stressσ0 obtained without considering the effect of inter-slice forces,and it can satisfy all static equilibrium conditions of the sliding body,so the current method can obtain the reasonable and strict factor of safety(FOS)solutions.Compared with the results of other methods in some examples,the feasibility of the current method was verified.Meanwhile,the parametric analysis shows that the slope angleβhas an important influence on the difference of the results obtained using the nonlinear HB strength criterion and its linear EMC strength parameters.Forβ≤45°,both of the results are similar,showing the traditional limit equilibrium methods using the linear EMC strength parameters and the current method are all suitable to analyze rock slope stability,but forβ>60°,the differences of both the results are obvious,showing the actual slope stability state can not be reflected in the traditional limit equilibrium methods,and then the current method should be used.
文摘在有限元极限分析(finite element limit analysis, FELA)的基础上,结合随机场理论,提出了网格自适应的边坡可靠性随机有限元极限分析方法,探讨了网格自适应前后的FELA法的确定性和可靠性分析结果,重点针对网格自适应FELA方法,从安全系数均值、分布规律及可靠度指标、潜在滑移面分布等角度分析了岩土参数变异系数和波动范围的影响.结果表明:考虑网格自适应的FELA能有效搜索潜在滑移面,在获得严格上、下限解的同时可显著提高边坡可靠性分析效率;通过随机场刻画参数变异特性能降低传统确定性分析对边坡稳定性的过高估计.随着变异系数的增大,安全系数概率密度曲线整体向左偏移,安全系数均值下降但变异性增大,坡体可靠度指标减小,坡体潜在滑面的分布更为离散;随着波动范围增大,出现了坡体安全系数均值增大但可靠性指标减小的互斥现象.相比黏聚力变异系数和水平波动范围,边坡可靠性分析结果对内摩擦角变异系数和竖向波动范围更为敏感.
