平推式滑坡成因机制及其稳定性评价
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摘要
平推式滑坡是一种特殊类型的滑坡,其隐蔽性往往会带来灾难性的后果。以重庆开县桌子石滑坡为案例,基于最新的研究成果和现场勘察结果,对滑坡的成因机制进行分析并对稳定性计算公式进行修正。理论和模型实验发现,软硬相间岩床会造成坡体产生阶梯式沉降,使得平推式滑坡下滑力增大,从而在较低的水位和降雨条件下发生快速下滑破坏。当后缘坡体发生阶梯沉降时,传统稳定性系数计算平均误差高达32.27%,采用考虑阶梯沉降的修正公式更加符合实际。在对桌子石滑坡进行稳定性计算时,后缘坡体阶梯沉降产生的推力是平推式滑坡稳定性评价不可忽略的关键因素。基于修正公式的稳定性系数由原有的1.179下降为1.031,与实际结果相符。因此,在对软硬相间岩床平推式滑坡进行安全评价分析时,要综合考虑阶梯式沉降等造成的抗滑力与滑动力因子的变异,才能保证稳定性评价的准确。
Translational landslide is a unique in the types of landslide that very often produces devastating consequences as its concealment. Latest studies and surveys results showed us the cause of Zhuozishi landslide in Kaixian,Chongqing City. We in this respect have built a new model for the translation landslide and have modified the formula previously used for stability measurement. The theoretical and experimental application of the model showed that the sliding force and the anti-sliding force of the landslide have been increased by the layered sedimentation of the soft and hard inter-phase rock bed. This resulted in the translational landslide in respect to lower water level or even lighter rainfall. The possibility of average error of the conventional stability coefficient is ranged up to 32.27% due to the stepped/layered formation of the bed rock. The new and modified formula is more objective in respect of considering the role of staircase subsidence. During the evaluation regarding the safety of Zhuozishi landslide,the coefficient of stability which was based on the new modified formula was reduced to 1.031 from 1.179 which is reliable and very much consistent with the actual and concrete observation results. It was find out through the result that the stepped settlement caused an increased sliding force which can be termed as the key factor in the assessment and evaluation of stability of translational landslide. It is therefore,suggested that for ensuring the accuracy of the safety assessment and evaluation of the translational landslide on the soft-hard interlaced rock strata,the variation and difference between the sliding and anti-sliding forces,primarily caused by stepped and layered subsidence,must be taken into consideration.
Translational landslide is a unique in the types of landslide that very often produces devastating consequences as its concealment. Latest studies and surveys results showed us the cause of Zhuozishi landslide in Kaixian,Chongqing City. We in this respect have built a new model for the translation landslide and have modified the formula previously used for stability measurement. The theoretical and experimental application of the model showed that the sliding force and the anti-sliding force of the landslide have been increased by the layered sedimentation of the soft and hard inter-phase rock bed. This resulted in the translational landslide in respect to lower water level or even lighter rainfall. The possibility of average error of the conventional stability coefficient is ranged up to 32.27% due to the stepped/layered formation of the bed rock. The new and modified formula is more objective in respect of considering the role of staircase subsidence. During the evaluation regarding the safety of Zhuozishi landslide,the coefficient of stability which was based on the new modified formula was reduced to 1.031 from 1.179 which is reliable and very much consistent with the actual and concrete observation results. It was find out through the result that the stepped settlement caused an increased sliding force which can be termed as the key factor in the assessment and evaluation of stability of translational landslide. It is therefore,suggested that for ensuring the accuracy of the safety assessment and evaluation of the translational landslide on the soft-hard interlaced rock strata,the variation and difference between the sliding and anti-sliding forces,primarily caused by stepped and layered subsidence,must be taken into consideration.
引文
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[10]涂园.平推式滑坡承压水模型研究[J].岩石力学与工程学报,2018,37(9):2 110-2 119.(TU Yuan.Study on the artesian water model of translational landslide[J].Chinese Journal of Rock Mechanics and Engineering,2018,37(9):2 110-2 119.(in Chinese))
[11]TIRANTI D,RABUFFETTI D,SALANDIN A,et al.Development of a new translational and rotational slides prediction model in Langhe hills(north-western Italy)and its application to the 2011 March landslide event[J].Landslides,2013,10(2):121-138.
[12]MULLER J R,MARTEL S J.Numerical models of translational landslide rupture surface growth[J].Pure and Applied Geophysics,2000,157(6/8):1 009-1 038.
[13]ZHAO Y,XU M,GUO J,et al.Accumulation characteristics,mechanism,and identification of an ancient translational landslide in China[J].Landslides,2015,12(6):1 119-1 130.
[14]吕美君,晏鄂川,程江涛.近水平岩层滑坡启动的临界水柱高度分析[J].岩土力学,2008,29(1):207-211.(LüMeijun,YAN Echuan,CHENG Jiangtao.Study on critical depth of fracture water for nearly horizontal strata landslide[J].Rock and Soil Mechanics,2008,29(1):207-211.(in Chinese))
[15]ZHANG M,YIN Y,HUANG B.Mechanisms of rainfall-induced landslides in gently inclined red beds in the eastern Sichuan Basin,SWChina[J].Landslides,2015,12(5):973-983.
[16]郭晓光,黄润秋,邓辉,等.平推式滑坡多级拉陷槽形成过程及成因机制分析[J].工程地质学报,2013,21(5):770-778.(GUOXiaoguang,HUANG Runqiu,DENG Hui,et al.Formation and mechanism analysis of multi-level rift though in translational sliding landslide[J].Journal of Engineering Geology,2013,21(5):770-778.(in Chinese))
[17]唐然,许强,吴斌,等.平推式滑坡运动距离计算模型研究[J].岩土力学,2018,39(3):1 009-1 019.(TANG Ran,XU Qiang,WU Bin,et al.Study on sliding distance calculation method of sub-horizontal translational landslides[J].Rock and Soil Mechanics,2018,39(3):1 009-1 019.(in Chinese))
[18]俞伯汀,孙红月,尚岳全,等.浙江下山滑坡特征及稳定性分析[J].岩石力学与工程学报,2006,25(增1):2 875-2 881.(YU Boting,SUN Hongyue,SHANG Yuequan,et al.Characteristics and stability analysis of Xiashan Landslide in Zhejiang province[J].Chinese Journal of Rock Mechanics and Engineering,2006,25(Supp.1):2 875-2 881.(in Chinese))
[19]王磊,李滨,高杨,等.大型厚层崩滑体运动特征模拟研究:以重庆武隆县羊角场镇大巷危岩为例[J].地学前缘,2016,23(2):251-259.(WANG Lie,LI Bin,GAO Yang,et al.Run-out prediction of large thick-bedded unstable rock:A case study of Daxiang unstable rock in Yangjiao town,Wulong county,Chongqing[J].Geoscience Frontiers,2016,23(2):251-259.(in Chinese))
[20]赵建军,肖建国,向喜琼,等.缓倾煤层采空区滑坡形成机制数值模拟研究[J].煤炭学报,2014,39(3):424-429.(ZHAO Jianjun,XIAO Jianguo,XIANG Xiqiong,et al.Failure mechanism numerical simulation of mining landslide with gentle bedding coal strata[J].Journal of China Coal Society,2014,39(3):424-429.(in Chinese))
[21]PETLEY D N,BULMER M H,MURPHY W.Patterns of movement in rotational and translational landslides[J].Geology,2002,30(8):719-722.
[22]SIMPSON D W.Seismicity changes associated with reservoir loading[J].Engineering Geology,1976,10(2/4):123-150.
[23]CHAI B,JIANG B,DU J,et al.Diagrammatize movement disintegration patterns of bedding rockslide[J].Environmental Earth Science,2016,75(4):323.
[2]HART M W.Bedding-parallel shear zones as landslide mechanisms in horizontal sedimentary rocks[J].Environmental and Engineering Geoscience,2000,6(2):95-114.
[3]MIKO?M,?ETINA M,BRILLY M.Hydrologic conditions responsible for triggering the Sto?e landslide,Slovenia[J].Engineering geology,2004,73(3):193-213.
[4]殷坤龙,简文星,周春梅,等.万州区近水平地层滑坡和堆积体成因机制与防治工程研究[R].武汉:中国地质大学,2005.(YINKunlong,JIAN Wenxing,ZHOU Chunmei,et al.Study on genetic mechanism and control method of landslides and accumulation body in horizontal bedded in Wanzhou[R].Wuhan:China University of Geosciences,2005.(in Chinese))
[5]范宣梅.平推式滑坡成因机制与防治对策研究[硕士学位论文][D].成都:成都理工大学,2007.(FAN Xuanmei.Study on genetic mechanism and control method of translational gliding landslide[M.S.Thesis][D].Chengdu:Chengdu University of Technology,2007.(in Chinese))
[6]赵勇,许模,赵红梅.平推式滑坡后缘启动水头探讨[J].人民长江,2011,42(17):32-36.(ZHAO Yong,XU Mo,ZHAO Hongmei.Discussion on starting water head in trailing edge of translational landslide[J].Yangtze River.2011,42(17):32-36.(in Chinese))
[7]赵权利,孙红月,王智磊,等.承压水对平推式滑坡的作用分析[J].岩石力学与工程学报,2012,31(2):596-602.(ZHAO Quanli,SUNHongyue,WANG Zhilei,et al.Influence of confined water on translational landslide[J].Chinese Journal of Rock Mechanics and Engineering,2012,31(2):596-602.(in Chinese))
[8]方贻立,马明,李聪,等.平推式滑坡致灾机制与减灾方法研究进展[J].长江科学院院报,2013,30(12):20-27.(FANG Yili,MA Ming,LI Cong,et al.Research advances in translational landslide?s mechanism and risk mitigation[J].Journal of Yangtze River Scientific Research Institute,2013,30(12):20-27.(in Chinese))
[9]肖建国,罗永康,贾志宏,等.平推式滑坡形成条件与防治措施[J].四川地质学报,2015,35(4):596-600.(XIAO Jianguo,LUOYongkang,JIA Zhihong,et al.Forming conditions and control of translational gliding landslide[J].Acta Geologica Sichuan,2015,35(4):596-600.(in Chinese))
[10]涂园.平推式滑坡承压水模型研究[J].岩石力学与工程学报,2018,37(9):2 110-2 119.(TU Yuan.Study on the artesian water model of translational landslide[J].Chinese Journal of Rock Mechanics and Engineering,2018,37(9):2 110-2 119.(in Chinese))
[11]TIRANTI D,RABUFFETTI D,SALANDIN A,et al.Development of a new translational and rotational slides prediction model in Langhe hills(north-western Italy)and its application to the 2011 March landslide event[J].Landslides,2013,10(2):121-138.
[12]MULLER J R,MARTEL S J.Numerical models of translational landslide rupture surface growth[J].Pure and Applied Geophysics,2000,157(6/8):1 009-1 038.
[13]ZHAO Y,XU M,GUO J,et al.Accumulation characteristics,mechanism,and identification of an ancient translational landslide in China[J].Landslides,2015,12(6):1 119-1 130.
[14]吕美君,晏鄂川,程江涛.近水平岩层滑坡启动的临界水柱高度分析[J].岩土力学,2008,29(1):207-211.(LüMeijun,YAN Echuan,CHENG Jiangtao.Study on critical depth of fracture water for nearly horizontal strata landslide[J].Rock and Soil Mechanics,2008,29(1):207-211.(in Chinese))
[15]ZHANG M,YIN Y,HUANG B.Mechanisms of rainfall-induced landslides in gently inclined red beds in the eastern Sichuan Basin,SWChina[J].Landslides,2015,12(5):973-983.
[16]郭晓光,黄润秋,邓辉,等.平推式滑坡多级拉陷槽形成过程及成因机制分析[J].工程地质学报,2013,21(5):770-778.(GUOXiaoguang,HUANG Runqiu,DENG Hui,et al.Formation and mechanism analysis of multi-level rift though in translational sliding landslide[J].Journal of Engineering Geology,2013,21(5):770-778.(in Chinese))
[17]唐然,许强,吴斌,等.平推式滑坡运动距离计算模型研究[J].岩土力学,2018,39(3):1 009-1 019.(TANG Ran,XU Qiang,WU Bin,et al.Study on sliding distance calculation method of sub-horizontal translational landslides[J].Rock and Soil Mechanics,2018,39(3):1 009-1 019.(in Chinese))
[18]俞伯汀,孙红月,尚岳全,等.浙江下山滑坡特征及稳定性分析[J].岩石力学与工程学报,2006,25(增1):2 875-2 881.(YU Boting,SUN Hongyue,SHANG Yuequan,et al.Characteristics and stability analysis of Xiashan Landslide in Zhejiang province[J].Chinese Journal of Rock Mechanics and Engineering,2006,25(Supp.1):2 875-2 881.(in Chinese))
[19]王磊,李滨,高杨,等.大型厚层崩滑体运动特征模拟研究:以重庆武隆县羊角场镇大巷危岩为例[J].地学前缘,2016,23(2):251-259.(WANG Lie,LI Bin,GAO Yang,et al.Run-out prediction of large thick-bedded unstable rock:A case study of Daxiang unstable rock in Yangjiao town,Wulong county,Chongqing[J].Geoscience Frontiers,2016,23(2):251-259.(in Chinese))
[20]赵建军,肖建国,向喜琼,等.缓倾煤层采空区滑坡形成机制数值模拟研究[J].煤炭学报,2014,39(3):424-429.(ZHAO Jianjun,XIAO Jianguo,XIANG Xiqiong,et al.Failure mechanism numerical simulation of mining landslide with gentle bedding coal strata[J].Journal of China Coal Society,2014,39(3):424-429.(in Chinese))
[21]PETLEY D N,BULMER M H,MURPHY W.Patterns of movement in rotational and translational landslides[J].Geology,2002,30(8):719-722.
[22]SIMPSON D W.Seismicity changes associated with reservoir loading[J].Engineering Geology,1976,10(2/4):123-150.
[23]CHAI B,JIANG B,DU J,et al.Diagrammatize movement disintegration patterns of bedding rockslide[J].Environmental Earth Science,2016,75(4):323.