推移式滑坡渐进破坏机制及稳定性分析
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摘要
在现行滑坡稳定分析的基础上,建立推移式滑坡渐进破坏稳定性分析法。在分析滑坡破坏机制的基础上,提出临界状态条块或单元,该临界状态条块或单元处于破坏和峰值应力之前两状态之间,并提出相应的决定方法。提出推移式滑坡2种破坏模式,模式I:整个滑体沿弱面发生推移破坏,模式II:后缘沿弱面发生推移破坏,而前缘局部沿滑体发生剪切破坏;在滑坡破坏控制的研究基础上,提出模式I滑坡破坏受弱面的基本力学特性所控制,对于模式II,滑坡后缘破坏受弱面的基本力学特性所控制,而前缘受滑体的抗剪力学特性所控制,2种破坏模式的临界状态逐步由后缘向前缘移动,也即是滑坡破坏不断地产生新的峰值应力状态和破坏后区状态。对推移式滑坡的变形规律进行研究,提出在滑坡模式I和II渐进破坏全过程中,滑坡破坏面上的每一点的时间与位移关系均会呈现不同的"S"型曲线特征,对于整个滑体而言,滑面上每一点的位移与高度关系曲线,在不同时刻呈现不同的抛物线型特征。分析滑面的位移与时间的关系曲线特征,提出滑面位移与时间的关系曲线呈现3种类型:类型a:I型非稳定时间曲线,类型b:I型稳定时间曲线,类型c:III型稳定时间曲线。研究现行滑坡稳定性系数的计算特点,提出滑坡稳定性计算的综合下滑力–抗滑力、主推力和基于位移变化的方法。研究了滑坡的运动特点,提出了主滑方向的定义,且主滑方向随力和位移的变化而变化。研究有限元滑坡稳定计算的特点,分析引起滑坡有限元法计算不收敛的原因,提出滑坡有限元计算的滑面边界法,其滑面既可以施加理想弹塑性模型边界,计算所得稳定系数可与传统的极限状态稳定计算结果相比较,又可以施加不同的应力–应变模型边界,从而获得真实的应力场和位移场,也可利用各种方法计算相对应的稳定系数;对于滑面确定可以采用各种优选计算和现场勘查方法。提出了各种对应关系图,这些图形有利于理解提出的系统理论。
A new method of stability analyses of thrust-type landslides was established based on the current methods of landslide stability analysis. A critical state between the failure and stable states was suggested based on the mechanism of thrust-type landslides and its determination was also proposed. Two failure modes were proposed for the progressive movement landslide. For the mode I,the whole slope failure occurred along the soft-weak layer. For the mode II,the landslide failure occurred in the rear edges along the soft-weak layer,and the shear failure happened at the front edge along the sliding body. The critical state moved from the rear zone to the front zone of the landslide progressively,i.e.,new critical state and failure zone are obtained for a progressive failure landslide during the deformation. The"S"shape curve of time and deformation is shown for the different points on the sliding face during deformation period. The relationship of deformation at different points on the sliding face and the height of landslide presents parabolic curve characteristics. Three kinds of curves between time and deformation were proposed based on the mechanical behavior classification of rock-soil mass. Types a and b are the unstable and stable curves between time and deformation of type I respectively,type c is the stable curve between time and deformation of type III. The stable analysis method for computing comprehensive slidingresistance,main thrust force and displacement based on deformation was suggested. The cause of divergence of FEM was analyzed. A new method to take the sliding face as a boundary condition of FEM was proposed for landslide stability analyses. The condition of sliding face boundary method was described not only with the perfect elasto-plastic model(PEPM),but also with the new constitutive model(JCM).
A new method of stability analyses of thrust-type landslides was established based on the current methods of landslide stability analysis. A critical state between the failure and stable states was suggested based on the mechanism of thrust-type landslides and its determination was also proposed. Two failure modes were proposed for the progressive movement landslide. For the mode I,the whole slope failure occurred along the soft-weak layer. For the mode II,the landslide failure occurred in the rear edges along the soft-weak layer,and the shear failure happened at the front edge along the sliding body. The critical state moved from the rear zone to the front zone of the landslide progressively,i.e.,new critical state and failure zone are obtained for a progressive failure landslide during the deformation. The"S"shape curve of time and deformation is shown for the different points on the sliding face during deformation period. The relationship of deformation at different points on the sliding face and the height of landslide presents parabolic curve characteristics. Three kinds of curves between time and deformation were proposed based on the mechanical behavior classification of rock-soil mass. Types a and b are the unstable and stable curves between time and deformation of type I respectively,type c is the stable curve between time and deformation of type III. The stable analysis method for computing comprehensive slidingresistance,main thrust force and displacement based on deformation was suggested. The cause of divergence of FEM was analyzed. A new method to take the sliding face as a boundary condition of FEM was proposed for landslide stability analyses. The condition of sliding face boundary method was described not only with the perfect elasto-plastic model(PEPM),but also with the new constitutive model(JCM).
引文
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[7]王建锋.两类经典滑坡发生时间预报模型的理论分析[J].地质力学学报,2004,10(1):40–50.(WANG Jianfeng.Theoretical analysis to two classic landslide prediction models:Saito′s model and Voight′s model[J].Journal of Geomechanics,2004,10(1):40–50.(in Chinese))
[8]卢应发,周盛沛,罗先启,等.渗流对抗滑桩加固滑坡后的影响效果评价[J].岩石力学与工程学报,2007,26(9):1 840–1 846.(LU Yingfa,ZHOU Shengpei,LUO Xianqi,et al.Evaluation of effects of seepage on landslide reinforced by anti-sliding piles[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(9):1 840–1 846.(in Chinese))
[9]卢应发,杨丽平,华国辉.一种新的节理本构模型及几种新的滑坡稳定系数计算方法[J].岩石力学与工程学报,2013,32(12):2 431–2 438.(LU Yingfa,YANG Liping,HUA Guohui.A new joint constitutive model and a few new methods of stability coefficient calculation of landslides[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(12):2 431–2 438.(in Chinese))
[10]卢应发,邓国栋,杨丽平,等.滑坡的关键块力学行为及力传递特征和不同应力状态的稳定系数研究[J].岩石力学与工程学报,2014,33(5):884–891.(LU Yingfa,DENG Guodong,YANG Liping,et al.Study of mechanical behaviors of key block and characteristics of force transmit and stability coefficient of different state stresses of landslides[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(5):884–891.(in Chinese))
[11]LU Y F.Deformation and failure mechanism of slope in three dimensions[J].Journal of Rock Mechanics and Geotechnical Engineering,2015,7(2):109–119.
[12]卢应发,石峻峰,刘德富.一种边坡稳定性计算的滑面边界法[P].中国:ZL 2014100250810,2014–04–16.(LU Yingfa,SHI Junfeng,LIU Defu.Method of stability analysis by boundary condition of sliding plane for the landslide[P].China:ZL 2014100250810,2014–04–16.(in Chinese))
[13]卢应发,刘德富,石峻峰.基于牵引式斜坡变形破坏机制的稳定性分析和预测预警方法[P].中国:ZL 201410025081.2,2014–07–23.(LU Yingfa,SHI Junfeng,LIU Defu.Method of stability analysis and prediction based on the deformation mechanism of Pull-type Landslide[P].China:ZL 201410025081.2,2014–07–23.(in Chinese))
[14]卢应发,路韬,周建军,等.一种新的节理模型及其在基桩分析中的应用[J].岩土力学,2013,34(4):967–973.(LU Yingfa,LU Tao,ZHOU Jianjun et al.A new joint constitutive model and its application to pile foundation analysis[J].Rock and Soil Mechanics,2013,34(4):967–973.(in Chinese))
[2]殷坤龙.降雨对滑坡的作用机制及动态模拟研究[J].地质科技情报,2002,21(1):75–78.(YIN Kunlong.Mechanism and dynamic simulation of landslide by precipitation[J].Geological Science and Technology Information,2002,21(1):75–78.(in Chinese))
[3]刘广润.论滑坡分类[J].工程地质学报,2002,10(4):339–340.(LIU Guangrun.Discussion on classification of landslides[J].Journal of Engineering Geology,2002,10(4):339–340.(in Chinese))
[4]姚海林.考虑裂隙及雨水入渗影响的膨胀土边坡稳定性分析[J].岩土工程学报,2001,23(5):606–609.(YAO Hailin.Analysis on the slope stability of expansive soils considering cracks and infiltration of rain[J].Chinese Journal of Geotechnical Engineering,2001,23(5):606–609.(in Chinese))
[5]杨诗义,雷学文.弱化改进后的灰色预测模型研究[J].山西建筑,2010,36(3):1–3.(YANG Shiyi,LEI Xuewen.Research on the gray forecasting model after weakening improvement[J].Shanxi Architecture,2010,36(3):1–3.(in Chinese))
[6]张珍,李世海,马力.重庆地区滑坡与降雨关系的概率分析[J].岩石力学与工程学报,2005,24(17):3 185–3 191.(ZHANG Zhen,LI Shihai.MA Li.Probability analysis of relationship between landslide and rainfall in Chongqing area[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(17):3 185–3 191.(in Chinese))
[7]王建锋.两类经典滑坡发生时间预报模型的理论分析[J].地质力学学报,2004,10(1):40–50.(WANG Jianfeng.Theoretical analysis to two classic landslide prediction models:Saito′s model and Voight′s model[J].Journal of Geomechanics,2004,10(1):40–50.(in Chinese))
[8]卢应发,周盛沛,罗先启,等.渗流对抗滑桩加固滑坡后的影响效果评价[J].岩石力学与工程学报,2007,26(9):1 840–1 846.(LU Yingfa,ZHOU Shengpei,LUO Xianqi,et al.Evaluation of effects of seepage on landslide reinforced by anti-sliding piles[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(9):1 840–1 846.(in Chinese))
[9]卢应发,杨丽平,华国辉.一种新的节理本构模型及几种新的滑坡稳定系数计算方法[J].岩石力学与工程学报,2013,32(12):2 431–2 438.(LU Yingfa,YANG Liping,HUA Guohui.A new joint constitutive model and a few new methods of stability coefficient calculation of landslides[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(12):2 431–2 438.(in Chinese))
[10]卢应发,邓国栋,杨丽平,等.滑坡的关键块力学行为及力传递特征和不同应力状态的稳定系数研究[J].岩石力学与工程学报,2014,33(5):884–891.(LU Yingfa,DENG Guodong,YANG Liping,et al.Study of mechanical behaviors of key block and characteristics of force transmit and stability coefficient of different state stresses of landslides[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(5):884–891.(in Chinese))
[11]LU Y F.Deformation and failure mechanism of slope in three dimensions[J].Journal of Rock Mechanics and Geotechnical Engineering,2015,7(2):109–119.
[12]卢应发,石峻峰,刘德富.一种边坡稳定性计算的滑面边界法[P].中国:ZL 2014100250810,2014–04–16.(LU Yingfa,SHI Junfeng,LIU Defu.Method of stability analysis by boundary condition of sliding plane for the landslide[P].China:ZL 2014100250810,2014–04–16.(in Chinese))
[13]卢应发,刘德富,石峻峰.基于牵引式斜坡变形破坏机制的稳定性分析和预测预警方法[P].中国:ZL 201410025081.2,2014–07–23.(LU Yingfa,SHI Junfeng,LIU Defu.Method of stability analysis and prediction based on the deformation mechanism of Pull-type Landslide[P].China:ZL 201410025081.2,2014–07–23.(in Chinese))
[14]卢应发,路韬,周建军,等.一种新的节理模型及其在基桩分析中的应用[J].岩土力学,2013,34(4):967–973.(LU Yingfa,LU Tao,ZHOU Jianjun et al.A new joint constitutive model and its application to pile foundation analysis[J].Rock and Soil Mechanics,2013,34(4):967–973.(in Chinese))