含软弱层岩质边坡的动力响应研究
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摘要
含软弱层岩质边坡的动力响应研究已成为边坡工程稳定性分析中的一个重要问题。为研究软弱层的特性对岩质边坡动力响应的影响,提供动力荷载作用下边坡防灾减灾的指导依据,运用UDEC离散元软件模拟地震力作用下含软弱层岩质边坡的动力响应系统地分析软弱层的倾角、埋深、弹性模量、厚度、泊松比和剪切刚度等因素对地震波放大现象的影响,得出边坡坡顶放大系数的变化规律,即随着软弱层倾角的增大,放大系数呈现出增大→减小→再增大→再减小,并出现地震响应减弱的现象;放大系数随软弱层埋深和厚度的增加而增大,但随弹性模量、剪切刚度的增大而减小,随泊松比的增加几乎不变。结合非重复性试验二元方差分析评价理论,对所得的放大系数进行计算分析,得出软弱层的特性因素对边坡放大作用的影响强度为软弱层的倾角>埋深>弹性模量>剪切刚度>厚度>泊松比。研究结果有助于进一步揭示地震作用下边坡的失稳机制,对震区边坡灾害的防治有一定的指导意义。
Researching on the dynamic response of the rock slopes with weak layer has become an important issue in slope stability analysis.In order to discuss the influences of dynamic response of rock slope by weak layer's characteristics and provide the directions and guidance for slope disaster prevention and mitigation under the dynamic load,the distinct element models are built and dynamic response of rock slopes with weak layer under seismic force are simulated by the universal distict element code(UDEC).After simulating in different conditions: various dip angles,burial depths,elastic moduli,thicknesses,Poisson's ratios and shear stiffness factors of the weak layer,the amplitude values of slope crest and bottom are obtained and the amplification coefficients are calculated;through systematically analyze the amplification coefficients,the amplification law of slope crest which influenced by seismic wave is got,namely,with increasing of dip angle,the amplification coefficient demonstrates increase→decrease→reincrease→decrease law,and appears response weakening phenomenon at the decreased parts.Along with burial depth and thickness increasing of weak layer,the amplification become bigger,but it decreases with elastic modulus and the shear stiffness increasing;the amplification almost doesn't change with increasing of Poisson's ratio.Combining with the non-repetitive test binary analysis of variance evaluation theory,the obtained slope amplification coefficients are analyzed;and then,it is obtained that the significant factors which contribute to the slope dynamic response from great to small are the dip angle,burial depth,elastic modulus,shear stiffness,thickness,Poisson's ratio of the weak layer.The results are helpful to further researches on the slope instability mechanism under earthquake,and can provide the significante guidance to slope disaster prevention in earthquake region.
Researching on the dynamic response of the rock slopes with weak layer has become an important issue in slope stability analysis.In order to discuss the influences of dynamic response of rock slope by weak layer's characteristics and provide the directions and guidance for slope disaster prevention and mitigation under the dynamic load,the distinct element models are built and dynamic response of rock slopes with weak layer under seismic force are simulated by the universal distict element code(UDEC).After simulating in different conditions: various dip angles,burial depths,elastic moduli,thicknesses,Poisson's ratios and shear stiffness factors of the weak layer,the amplitude values of slope crest and bottom are obtained and the amplification coefficients are calculated;through systematically analyze the amplification coefficients,the amplification law of slope crest which influenced by seismic wave is got,namely,with increasing of dip angle,the amplification coefficient demonstrates increase→decrease→reincrease→decrease law,and appears response weakening phenomenon at the decreased parts.Along with burial depth and thickness increasing of weak layer,the amplification become bigger,but it decreases with elastic modulus and the shear stiffness increasing;the amplification almost doesn't change with increasing of Poisson's ratio.Combining with the non-repetitive test binary analysis of variance evaluation theory,the obtained slope amplification coefficients are analyzed;and then,it is obtained that the significant factors which contribute to the slope dynamic response from great to small are the dip angle,burial depth,elastic modulus,shear stiffness,thickness,Poisson's ratio of the weak layer.The results are helpful to further researches on the slope instability mechanism under earthquake,and can provide the significante guidance to slope disaster prevention in earthquake region.
引文
[1]黄润秋,李为乐.“5 12”汶川大地震触发地质灾害的发育分布规律研究[J].岩石力学与工程学报,2008,27(12):2586-2591.HUANG Run-qiu,LI Wei-le.Research on development and distribution rules of geohazards induced by Wenchuan earthquake on 12th May,2008[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(12):2586-2591.
[2]刘亚群,李海波,李俊如,等.爆破荷载作用下黄麦岭磷矿岩质边坡动态响应的UDEC模拟研究[J].岩石力学与工程学报,2004,23(21):3659-3663.LIU Ya-qun,LI Hai-bo,LI Jun-ru,et al.UDEC simulation on dynamic response of rock slope of Huangmailing phosphorite mine under explosion[J].Chinese Journal of Rock Mechanics and Engineering,2004,23(21):3659-3663.
[3]刘红星,苏爱军,王永平,等.软弱夹层对斜坡稳定性的影响分析[J].武汉理工大学学报(交通科学与工程版),2004,28(5):766-770.LIU Hong-xing,SU Ai-jun,WANG Yong-ping,et al.Analysisof affection of weak seam to slope stability[J].Journal of Wuhan University of Technology(Transportation Science&Engineering),2004,28(5):766770.
[4]黄润秋.20世纪以来中国的大型滑坡及其发生机制[J].岩石力学与工程学报,2007,26(3):434-451.HUANG Run-qiu.Large scale landslides and their sliding mechanisms in China since the 20th century[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(3):434-451.
[5]杜晓丽,宋宏伟,魏京胜.地震对软弱夹层边坡稳定性影响素质模拟研究[J].三峡大学学报(自然科学版),2010,32(1):39-42.DU Xiao-li,SONG Hong-wei,WEI Jing-sheng.Numerical simulation research on stability of slope with weak sandwich under seismic loadings[J].Journal of China Three Gerges Univ.(Natural Sciences),2010,32(1):39-42.
[6]柴红保,曹平,林杭.竖直向上传播剪切波作用下边坡动力响应规律[J].中南大学学报(自然科学版),2011,42(4):1079-1084.CHAI Hong-bao,CAO Ping,LIN Hang.Dynamic response laws of slope under vertical shear wave[J].Journal of Central South University(Science and Technology),2011,42(4):1079-1084.
[7]黄润秋,余嘉顺.软弱夹层特性对地震波强度影响的模拟研究[J].工程地质学报,2003,11(3):312-317.HUANG Run-qiu,YU Jia-shun.Modeling of the effects of properties of a buried weak layer on seismic waves[J].Journal of Engineering Geology,2003,11(3):312317.
[8]范留明,李宁.软弱夹层的透射模型及其隔震特性研究[J].岩石力学与工程学报,2005,24(14):2456-2461.FAN Liu-ming,LI Ning.Transmission model of weak intercalation and its vibration isolation properties[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(14):2456-2461.
[9]范留明,闫娜,李宁.薄弹性软弱夹层的动力响应模型[J].岩石力学与工程学报,2006,25(1):88-91.FAN Liu-ming,YAN Na,LI Ning.Dynamic response model for thin soft interlayer considering interbedded reflecting waves[J].Chinese Journal of Rock Mechanics and Engineering,2006,25(1):88-91.
[10]KUHLEMEYER R L,LYSMER J.Finite element method accuracy for wave propagation problems[J].Journal of the Soil Mechanics and Foundations Division,1973,99(5):421-417.
[11]Itasca Consulting Group.UDEC(universal distinct element code)user’s manual(version 3.0)[M].Minneapolis:Itasca Consulting Group,1996.
[12]言志信,郭斌,贺香,等.多级边坡平台宽度对边坡地震动力响应及破坏机制的影响[J].岩土力学,2012,33(增刊2):352-357.YAN Zhi-xin,GUO Bin,HE Xiang,et al.Study of effect of platform width on dynamic response and failure mechanism of stepped slops under earthquake[J].Rock and Soil Mechanics,2012,33(Supp.2):352-357.
[13]汪荣鑫.数理统计[M].西安:西安交通大学出版社,2005.
[2]刘亚群,李海波,李俊如,等.爆破荷载作用下黄麦岭磷矿岩质边坡动态响应的UDEC模拟研究[J].岩石力学与工程学报,2004,23(21):3659-3663.LIU Ya-qun,LI Hai-bo,LI Jun-ru,et al.UDEC simulation on dynamic response of rock slope of Huangmailing phosphorite mine under explosion[J].Chinese Journal of Rock Mechanics and Engineering,2004,23(21):3659-3663.
[3]刘红星,苏爱军,王永平,等.软弱夹层对斜坡稳定性的影响分析[J].武汉理工大学学报(交通科学与工程版),2004,28(5):766-770.LIU Hong-xing,SU Ai-jun,WANG Yong-ping,et al.Analysisof affection of weak seam to slope stability[J].Journal of Wuhan University of Technology(Transportation Science&Engineering),2004,28(5):766770.
[4]黄润秋.20世纪以来中国的大型滑坡及其发生机制[J].岩石力学与工程学报,2007,26(3):434-451.HUANG Run-qiu.Large scale landslides and their sliding mechanisms in China since the 20th century[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(3):434-451.
[5]杜晓丽,宋宏伟,魏京胜.地震对软弱夹层边坡稳定性影响素质模拟研究[J].三峡大学学报(自然科学版),2010,32(1):39-42.DU Xiao-li,SONG Hong-wei,WEI Jing-sheng.Numerical simulation research on stability of slope with weak sandwich under seismic loadings[J].Journal of China Three Gerges Univ.(Natural Sciences),2010,32(1):39-42.
[6]柴红保,曹平,林杭.竖直向上传播剪切波作用下边坡动力响应规律[J].中南大学学报(自然科学版),2011,42(4):1079-1084.CHAI Hong-bao,CAO Ping,LIN Hang.Dynamic response laws of slope under vertical shear wave[J].Journal of Central South University(Science and Technology),2011,42(4):1079-1084.
[7]黄润秋,余嘉顺.软弱夹层特性对地震波强度影响的模拟研究[J].工程地质学报,2003,11(3):312-317.HUANG Run-qiu,YU Jia-shun.Modeling of the effects of properties of a buried weak layer on seismic waves[J].Journal of Engineering Geology,2003,11(3):312317.
[8]范留明,李宁.软弱夹层的透射模型及其隔震特性研究[J].岩石力学与工程学报,2005,24(14):2456-2461.FAN Liu-ming,LI Ning.Transmission model of weak intercalation and its vibration isolation properties[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(14):2456-2461.
[9]范留明,闫娜,李宁.薄弹性软弱夹层的动力响应模型[J].岩石力学与工程学报,2006,25(1):88-91.FAN Liu-ming,YAN Na,LI Ning.Dynamic response model for thin soft interlayer considering interbedded reflecting waves[J].Chinese Journal of Rock Mechanics and Engineering,2006,25(1):88-91.
[10]KUHLEMEYER R L,LYSMER J.Finite element method accuracy for wave propagation problems[J].Journal of the Soil Mechanics and Foundations Division,1973,99(5):421-417.
[11]Itasca Consulting Group.UDEC(universal distinct element code)user’s manual(version 3.0)[M].Minneapolis:Itasca Consulting Group,1996.
[12]言志信,郭斌,贺香,等.多级边坡平台宽度对边坡地震动力响应及破坏机制的影响[J].岩土力学,2012,33(增刊2):352-357.YAN Zhi-xin,GUO Bin,HE Xiang,et al.Study of effect of platform width on dynamic response and failure mechanism of stepped slops under earthquake[J].Rock and Soil Mechanics,2012,33(Supp.2):352-357.
[13]汪荣鑫.数理统计[M].西安:西安交通大学出版社,2005.
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