塑流-拉裂式崩塌机制及评价方法
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摘要
塑流–拉裂式崩塌或软弱基座型崩塌是我国西南山区和三峡库区常见的一种崩塌类型。当危岩体的下部有较厚的软弱岩层时,此类崩塌发生尤为频繁。软弱岩层在上部岩体压力作用、遇水软化、长期风化剥落等因素作用下,不断压缩并向临空方向塑性流动,导致上覆较坚硬岩层拉裂形成塑流–拉裂式危岩体。离散元模拟得到此类崩塌的变形破坏地质过程为:软岩风化剥落→上部硬岩局部坠落→软弱基座挤出变形→上部硬岩产生下宽上窄拉裂缝→变形继续发展→崩塌产生。根据软弱层不均匀变形前后上部被拉裂硬岩的2种不同破坏模式,应用地质力学分析方法,推导塑流–拉裂式崩塌稳定系数计算公式。以三峡地区万州某边坡为例,采用抗压强度–压应力比值分析法和软弱层不均匀变形稳定性分析法进行对比分析。结果表明:静力条件下,危岩体短期内处于稳定状态;高地震烈度条件下,危岩体不稳定。
The plastic-flow and tensile crack-type collapse or soft foundation-type collapse are very common in Southwest mountain region and Three Gorges reservoir area in China.These types of collapse occur frequently when weak layer distributes under the perilous rock mass.Suffering from the influence of gravity,water softening,long-term weathering and spalling,the weak layer will generate horizontal plastic flow towards free face.Meanwhile,the hard rock will generate tensile cracks.At last,perilous rock mass will generate uneven deformation in a weak layer.The deformation and failure processes of numerical simulation by discrete element method(DEM) are mudstone weathering and sheet-like peeling,hard rock falling,weak pedestal squeezing out,tension crack opening,deformation increasing and collapse occurring.According to two different failure modes of perilous rock mass caused by inhomogeneous deformation of weak layer,the computing formula of stability coefficient of plastic flow and tensile crack-type collapse is deduced by means of the method of geomechanics.Taking a typical rock slope in Wanzhou area of the Three Gorges area for example,the serious contrast and analysis of ratio of compressive strength to compressive stress and stability analysis of inhomogeneous deformation of weak layer are conducted.The results show that under static condition,the perilous rock mass is stable in a short term,on the contrary,it is unstable under high seismic intensity conditions.
The plastic-flow and tensile crack-type collapse or soft foundation-type collapse are very common in Southwest mountain region and Three Gorges reservoir area in China.These types of collapse occur frequently when weak layer distributes under the perilous rock mass.Suffering from the influence of gravity,water softening,long-term weathering and spalling,the weak layer will generate horizontal plastic flow towards free face.Meanwhile,the hard rock will generate tensile cracks.At last,perilous rock mass will generate uneven deformation in a weak layer.The deformation and failure processes of numerical simulation by discrete element method(DEM) are mudstone weathering and sheet-like peeling,hard rock falling,weak pedestal squeezing out,tension crack opening,deformation increasing and collapse occurring.According to two different failure modes of perilous rock mass caused by inhomogeneous deformation of weak layer,the computing formula of stability coefficient of plastic flow and tensile crack-type collapse is deduced by means of the method of geomechanics.Taking a typical rock slope in Wanzhou area of the Three Gorges area for example,the serious contrast and analysis of ratio of compressive strength to compressive stress and stability analysis of inhomogeneous deformation of weak layer are conducted.The results show that under static condition,the perilous rock mass is stable in a short term,on the contrary,it is unstable under high seismic intensity conditions.
引文
[1]陈洪凯,唐红梅,王蓉.三峡库区危岩稳定性计算方法及应用[J].岩石力学与工程学报,2004,23(4):614–619.(CHEN Hongkai,TANG Hongmei,WANG Rong.Calculation method of stability forunstable rock and application to the Three Gorges Reservoir[J].ChineseJournal of Rock Mechanics and Engineering,2004,23(4):614–619.(inChinese))
[2]殷跃平.三峡库区边坡结构及失稳模式研究[J].工程地质学报,2005,13(2):145–154.(YIN Yueping.Human-cutting slope structureand failure pattern at the Three Gorges Reservoir[J].Journal ofEngineering Geology,2005,13(2):145–154.(in Chinese))
[3]ZARUBA Q,MENCL V.Engineering geology[M].Amsterdam:Elsevier Publishers,1976.
[4]张倬元,王士天,王兰生.工程地质分析原理[M].北京:地质出版社,1994:335–336.(ZHANG Zhuoyuan,WANG Shitian,WANGLansheng.Principles of engineering geology[M].Beijing:GeologicalPublishing House,1994:335–336.(in Chinese))
[5]陈广波.塑流–拉裂型滑坡地质特征及形成机制[J].铁道工程学报,1996,49(1):93–102.(CHEN Guangbo.Geology feature of plasticflow and tensile crack type landslide and its formation mechanism[J].Journal of Railway Engineering Society,1996,49(1):93–102.(inChinese))
[6]REN G M,LI T B,XU J.The study of geo-mechanical simulation ondeformation and failure in deep zone of the Huanglashi landslide[C]//Proceedings of Seventh International Congress of International Associationof Engineering Geology.[S.l.]:[s.n.],1994:1 647–1 652.(in Chinese))
[7]任光明,宋彦辉,聂德新,等.软弱基座型斜坡变形破坏过程研究[J].岩石力学与工程学报,2003,22(9):1510–1513.(REN Guangming,SONG Yanhui,NIE Dexin,et al.Study of deformation and failureprocess of soft foundation slope[J].Chinese Journal of Rock Mechanics andEngineering,2003,22(9):1 510–1 513.(in Chinese))
[8]罗永忠,徐志文,祝世强.达县城区立石子危岩形成机制分析及稳定性评价[J].地质灾害与环境保护,2004,15(2):32–37.(LUOYongzhong,XU Zhiwen,ZHU Shiqiang.Formation mechanismanalysis and stability evaluation in dangerous rock body of Lishizhi inDaxian urban area[J].Journal of Geological Hazards and EnvironmentPreservation,2004,15(2):32–37.
[9]胡厚田.崩塌落石研究[J].铁道工程学报,2005,(增):387–391.(HU Houtian.Research on the collapse and falling stone[J].Journal ofRailway Engineering Society,2005,(Supp.):387–391.(in Chinese))
[10]陈小婷,黄波林,刘广宁,等.三峡库区平缓层状软硬相间斜坡变形模式变化分析[J].地质灾害与环境保护,2009,20(2):57–61.(CHEN Xiaoting,HUANG Bolin,LIU Guangning,et al.Analysis ofdeforming mode transforming of gentle soft hard interbed slopes inThree Gorges reservoir[J].Journal of Geological Hazards and EnvironmentPreservation,2009,20(2):57–61.(in Chinese))
[11]唐红梅,王林峰,陈洪凯,等.软弱基座陡崖上危岩崩落序列[J].岩石力学与工程学报,2010,32(2):205–210.(TANG Hongmei,WANGLinfeng,CHEN Hongkai,et al.Collapse sequence of perilous rock oncliffs with soft foundation[J].Chinese Journal of Rock Mechanics andEngineering,2010,32(2):205–210.(in Chinese))
[12]吉随旺,张倬元,王凌云,等.近水平软硬互层斜坡变形破坏机制[J].中国地质灾害与防治学报,2000,11(3):49–52.(JI Suiwang,ZHANG Zhuoyuan,WANG Lingyun,et al.Mechanism of deformationand failure for the slope composed of nearly horizontal competent andincompetent intercalated rock mass strata[J].The Chinese Journal ofGeological Hazard and Control,2000,11(3):49–52.(in Chinese))
[13]柴贺军,肖文.具有软弱基座逆向边坡变形及破坏过程研究[J].地球科学进展,2004,19(增):288–291.(CHAI Hejun,XIAO Wen.Research on deformation and destructive process of reverse slope withsoft foundation[J].Advance in Earth Sciences,2004,19(Supp.):288–291.(in Chinese))
[14]傅鹤林,卜翠松,周中,等.贵州崩塌滑坡的特点及防治技术[J].湘南学院学报,2005,26(5):39–45.(FUHelin,BUCuisong,ZHOUZhong,et al.The characteristics of collapses and landslides and itspreventing technologies in Guizhou of China[J].Journal of XiangnanUniversity,2005,26(5):39–45.(in Chinese))
[15]卢全中,赵法锁,彭建兵.某软弱基座型斜坡的稳定性分析[J].公路交通科技,2005,22(6):63–65.(LU Quanzhong,ZHAO Fasuo,PENG Jianbing.Analysis of stability of a slope with soft base[J].Journal of Highway and Transportation Research and Development,2005,22(6):63–65.(in Chinese))
[16]董金玉,杨继红,伍法权,等.三峡库区软硬互层近水平地层高切坡崩塌研究[J].岩土力学,2010,31(1):151–157.(DONG Jinyu,YANG Jihong,WU Faquan,et al.Research on collapse of high cuttingslope with horizontal soft-hard alternant strata in Three Gorgesreservoir area[J].Rock and Soil Mechanics,2010,31(1):151–157.(in Chinese))
[17]刘国明,林义兴,夏颂佑,等.三峡链子崖危岩体静力稳定性有限元分析[J].河海大学学报,1996,24(4):95–101.(LIU Guoming,LIN Yixing,XIA Songyou,et al.FEM analysis of static stability forLianzi cliff perilous rock in Three Gorges area[J].Journal of HohaiUniversity,1996,24(4):95–101.(in Chinese))
[18]DORREN L K A.A review of rockfall mechanics and modelingapproaches[J].Progress in Physical Geography,2003,27(1):69–87.
[19]Itasca Consulting Group Inc..UDEC user s manual,version 4.0[R].[S.l]:Itasca Consulting Group Inc.,2004.
[20]王根龙.崩塌地质灾害机制及评价方法研究[博士后研究工作报告][R].北京:中国科学院地质与地球物理研究所,2011.(WANGGenlong.Research on failure mechanism and assessment techniquesfor rock fall geological hazard[Report of Postdoctoral Research][R].Bejing:Institute of Geology and Geophysics,Chinese Academy ofSciences,2011.(in Chinese))
[21]陈洪凯,唐红梅,崔志波,等.公路高边坡地质安全与减灾[M].北京:科学出版社,2010:158–159.(CHEN Hongkai,TANG Hongmei,CUI Zhibo,et al.Geological security and disaster reduction for highslopes of highway[M].Beijing:Science Press,2010:158–159.(inChinese))
[2]殷跃平.三峡库区边坡结构及失稳模式研究[J].工程地质学报,2005,13(2):145–154.(YIN Yueping.Human-cutting slope structureand failure pattern at the Three Gorges Reservoir[J].Journal ofEngineering Geology,2005,13(2):145–154.(in Chinese))
[3]ZARUBA Q,MENCL V.Engineering geology[M].Amsterdam:Elsevier Publishers,1976.
[4]张倬元,王士天,王兰生.工程地质分析原理[M].北京:地质出版社,1994:335–336.(ZHANG Zhuoyuan,WANG Shitian,WANGLansheng.Principles of engineering geology[M].Beijing:GeologicalPublishing House,1994:335–336.(in Chinese))
[5]陈广波.塑流–拉裂型滑坡地质特征及形成机制[J].铁道工程学报,1996,49(1):93–102.(CHEN Guangbo.Geology feature of plasticflow and tensile crack type landslide and its formation mechanism[J].Journal of Railway Engineering Society,1996,49(1):93–102.(inChinese))
[6]REN G M,LI T B,XU J.The study of geo-mechanical simulation ondeformation and failure in deep zone of the Huanglashi landslide[C]//Proceedings of Seventh International Congress of International Associationof Engineering Geology.[S.l.]:[s.n.],1994:1 647–1 652.(in Chinese))
[7]任光明,宋彦辉,聂德新,等.软弱基座型斜坡变形破坏过程研究[J].岩石力学与工程学报,2003,22(9):1510–1513.(REN Guangming,SONG Yanhui,NIE Dexin,et al.Study of deformation and failureprocess of soft foundation slope[J].Chinese Journal of Rock Mechanics andEngineering,2003,22(9):1 510–1 513.(in Chinese))
[8]罗永忠,徐志文,祝世强.达县城区立石子危岩形成机制分析及稳定性评价[J].地质灾害与环境保护,2004,15(2):32–37.(LUOYongzhong,XU Zhiwen,ZHU Shiqiang.Formation mechanismanalysis and stability evaluation in dangerous rock body of Lishizhi inDaxian urban area[J].Journal of Geological Hazards and EnvironmentPreservation,2004,15(2):32–37.
[9]胡厚田.崩塌落石研究[J].铁道工程学报,2005,(增):387–391.(HU Houtian.Research on the collapse and falling stone[J].Journal ofRailway Engineering Society,2005,(Supp.):387–391.(in Chinese))
[10]陈小婷,黄波林,刘广宁,等.三峡库区平缓层状软硬相间斜坡变形模式变化分析[J].地质灾害与环境保护,2009,20(2):57–61.(CHEN Xiaoting,HUANG Bolin,LIU Guangning,et al.Analysis ofdeforming mode transforming of gentle soft hard interbed slopes inThree Gorges reservoir[J].Journal of Geological Hazards and EnvironmentPreservation,2009,20(2):57–61.(in Chinese))
[11]唐红梅,王林峰,陈洪凯,等.软弱基座陡崖上危岩崩落序列[J].岩石力学与工程学报,2010,32(2):205–210.(TANG Hongmei,WANGLinfeng,CHEN Hongkai,et al.Collapse sequence of perilous rock oncliffs with soft foundation[J].Chinese Journal of Rock Mechanics andEngineering,2010,32(2):205–210.(in Chinese))
[12]吉随旺,张倬元,王凌云,等.近水平软硬互层斜坡变形破坏机制[J].中国地质灾害与防治学报,2000,11(3):49–52.(JI Suiwang,ZHANG Zhuoyuan,WANG Lingyun,et al.Mechanism of deformationand failure for the slope composed of nearly horizontal competent andincompetent intercalated rock mass strata[J].The Chinese Journal ofGeological Hazard and Control,2000,11(3):49–52.(in Chinese))
[13]柴贺军,肖文.具有软弱基座逆向边坡变形及破坏过程研究[J].地球科学进展,2004,19(增):288–291.(CHAI Hejun,XIAO Wen.Research on deformation and destructive process of reverse slope withsoft foundation[J].Advance in Earth Sciences,2004,19(Supp.):288–291.(in Chinese))
[14]傅鹤林,卜翠松,周中,等.贵州崩塌滑坡的特点及防治技术[J].湘南学院学报,2005,26(5):39–45.(FUHelin,BUCuisong,ZHOUZhong,et al.The characteristics of collapses and landslides and itspreventing technologies in Guizhou of China[J].Journal of XiangnanUniversity,2005,26(5):39–45.(in Chinese))
[15]卢全中,赵法锁,彭建兵.某软弱基座型斜坡的稳定性分析[J].公路交通科技,2005,22(6):63–65.(LU Quanzhong,ZHAO Fasuo,PENG Jianbing.Analysis of stability of a slope with soft base[J].Journal of Highway and Transportation Research and Development,2005,22(6):63–65.(in Chinese))
[16]董金玉,杨继红,伍法权,等.三峡库区软硬互层近水平地层高切坡崩塌研究[J].岩土力学,2010,31(1):151–157.(DONG Jinyu,YANG Jihong,WU Faquan,et al.Research on collapse of high cuttingslope with horizontal soft-hard alternant strata in Three Gorgesreservoir area[J].Rock and Soil Mechanics,2010,31(1):151–157.(in Chinese))
[17]刘国明,林义兴,夏颂佑,等.三峡链子崖危岩体静力稳定性有限元分析[J].河海大学学报,1996,24(4):95–101.(LIU Guoming,LIN Yixing,XIA Songyou,et al.FEM analysis of static stability forLianzi cliff perilous rock in Three Gorges area[J].Journal of HohaiUniversity,1996,24(4):95–101.(in Chinese))
[18]DORREN L K A.A review of rockfall mechanics and modelingapproaches[J].Progress in Physical Geography,2003,27(1):69–87.
[19]Itasca Consulting Group Inc..UDEC user s manual,version 4.0[R].[S.l]:Itasca Consulting Group Inc.,2004.
[20]王根龙.崩塌地质灾害机制及评价方法研究[博士后研究工作报告][R].北京:中国科学院地质与地球物理研究所,2011.(WANGGenlong.Research on failure mechanism and assessment techniquesfor rock fall geological hazard[Report of Postdoctoral Research][R].Bejing:Institute of Geology and Geophysics,Chinese Academy ofSciences,2011.(in Chinese))
[21]陈洪凯,唐红梅,崔志波,等.公路高边坡地质安全与减灾[M].北京:科学出版社,2010:158–159.(CHEN Hongkai,TANG Hongmei,CUI Zhibo,et al.Geological security and disaster reduction for highslopes of highway[M].Beijing:Science Press,2010:158–159.(inChinese))
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