目前反倾岩质边坡弯曲倾倒破坏分析方法仍以基于极限平衡理论的悬臂梁模型为主,但大多未考虑坡脚岩层的剪切破坏。为准确评价该类边坡的稳定性,建立考虑坡脚岩层剪切破坏的分析计算方法。首先,根据岩层变形破坏特征,将边坡分为后缘稳定区、中部弯曲倾倒区和前缘剪切区3个区域;其次,建立弯曲倾倒-剪切滑移破坏模式的稳定性分析方法;最后,通过工程实例验证,并进行参数分析。研究结果表明:提出的分析方法与工程实际符合性较好;边坡在倾角较陡、坡角较大时稳定性最差,坡角对边坡稳定性影响大于岩层倾角的影响;岩层厚度及层面内摩擦角增加有利于边坡稳定性,且会扩大坡脚剪切区范围。研究成果对反倾岩质边坡破坏的防治具有实践指导意义。
Abstract
At present, the cantilever beam model based on the limit equilibrium theory is still the main method to analyze the flexural toppling failure of counter-tilted rock slopes, but most do not consider the shear failure of the rock layer at the toe of the slope. According to the deformation and failure characteristics of rock layer, we divided the slope into three zones: stable zone in the back edge, flexural toppling zone in the middle, and shear zone in the front edge. In subsequence, we established the analytical method for flexural toppling-shear sliding failure mode and verified the analytical method through application in an engineering example and analyzed the model parameters. Results manifest that the result obtained by the proposed analytical method is in good agreement with actual engineering. The slope stability is at the worst in the presence of large dip angle of rock layer and slope angle. The influence of slope angle on slope stability is greater than that of dip angle of rock layer. The increment in the thickness and internal friction angle of rock layer is conducive to slope stability and will widen the scope of the shear zone at slope toe.
关键词
反倾岩质边坡 /
弯曲倾倒 /
剪切滑移 /
极限平衡理论 /
坡脚岩层
Key words
counter-tilted rock slope /
flexural toppling /
shear sliding /
limit equilibrium theory /
rock strata at slope toe
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参考文献
[1] 张世殊,裴向军,王仁坤,等. 狮子坪水电站二古溪倾倒边坡成因机制分析[J]. raybet体育在线
院报,2014,31(11):60-65.
[2] 刘顺昌. 如美水电站岩质边坡倾倒破坏机制研究[D].武汉: 中国地质大学, 2013.
[3] 左保成,陈从新,刘小巍,等. 反倾岩质边坡破坏机理模型试验研究[J]. 岩石力学与工程学报, 2005,24(19):3505-3511.
[4] 王思敬. 金川露天矿边坡变形机制及过程[J]. 岩土工程学报,1982(1):76-83.
[5] ASHBY J. Sliding and Toppling Modes of Failure in Models and Jointed Rock Slopes[D]. London: Imperial College, University of London, 1971.
[6] GOODMAN R E. Toppling of Rock Slope[C]//Proceedings of a Specialty Conference on Rock Engineering for Foundations and Slopes. Boulder, Colorado: University of Colorado, August 15-18, 1976: 201-234.
[7] 高连通,晏鄂川,谢良甫.考虑地下水作用的Goodman-Bray方法改进及应用[J]. raybet体育在线
院报,2015,32(2):78-83.
[8] AYDAN O,KAWAMOTO T. The Stability of Slopes and Underground Opening against Flexural Toppling and Their Stabilization[J]. Rock Mechanics and Rock Engineering,1992, 25(3): 143-165.
[9] ADHIKARY D P, DYSKIN A V, JEWELL R J, et al. A Study of the Mechanism of Flexural Toppling Failure of Rock Slopes[J]. Rock Mechanics and Rock Engineering,1997, 30(2): 75-93.
[10] ZHANG G,WANG F,ZHANG H,et al. New Stability Calculation Method for Rock Slopes Subject to Flexural Toppling Failure[J]. International Journal of Rock Mechanics & Mining Sciences,2018,106:319-328.
[11] AMINI M,MAJDI A,VESHADI M A. Stability Analysis of Rock Slopes against Block-Flexure Toppling Failure[J]. Rock Mechanics and Rock Engineering, 2012, 45(4): 519-532.
[12] 孙朝燚,陈从新,郑 允,等. 岩质反倾边坡复合倾倒破坏分析[J]. 湖南大学学报(自然科学版),2020,47(1):130-138.
[13] 王俊杰,郭建军. 反倾岩质边坡次生倾倒机理及稳定性分析[J]. 岩土工程学报,2019,41(9):1619-1627.
[14] 刘海军. 皖南山区反倾板岩边坡倾倒变形机理研究[D]. 成都:成都理工大学,2012.
[15] ALZO'UBI A K,MARTIN C D,RUDEN D M. Influence of Tensile Strength on Toppling Failure in Centrifuge Tests[J]. International Journal of Rock Mechanics & Mining Sciences,2010,47(6):974-982.
[16] 卢海峰,刘泉声,陈从新. 反倾岩质边坡悬臂梁极限平衡模型的改进[J]. 岩土力学,2012,33(2):577-584.
基金
贵州省交通运输厅科技项目(2014141030)
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