“12·20”深圳滑坡动态模拟
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摘要
将深圳滑坡堆填渣土近似视为饱和土,考虑快速填筑效应,假定填筑高度在填筑过程中随时间线性增大,由一维固结理论推导出由于快速加载引起的土体内超静孔隙水压力分布,同时根据修正剑桥模型考虑填土剪缩效应对超静孔隙水压力的影响。总孔隙水压力为静水压力、快速加载和剪缩引起的超静孔隙水压力三部分之和,从而由总应力得到余泥渣土失稳时的有效应力,进而由有效内摩擦角得到其剪切强度。再将快速滑出过程看作不排水条件下的破坏,利用推导出的填土不排水强度,采用可以有效模拟超大变形问题的物质点法对深圳滑坡的全过程进行了动态模拟,并研究了滑坡体对建筑物的破坏作用。模拟结果表明该模型能较好解释深圳滑坡中滑动土体高速远程输送特征。
The filled soil of Shenzhen landslide is treated as saturated porous media. The excess pore pressure due to fast filling process is derived using the classical one-dimensional consolidation theory by assuming the thickness of the filled soil to increase linearly. Meanwhile, another part of the excess pore pressure induced by the soil contraction under shear deformation is derived by using the modified Cam-clay model. Then the effective stress is obtained by subtracting the pore pressure, i.e., the static pore pressure and the two parts of the excess pore pressure, from the total stress. The undrained shear strength can be expressed by the effective friction angle and the effective stress. Finally, the landslide is simulated using the material point method by assuming an undrained run-out process in which the soil strength keeps constant. The destructive effect of the sliding soil on the buildings is also analyzed. The proposed theory can be used to explain the extraordinary flow ability of the soil satisfactorily.
The filled soil of Shenzhen landslide is treated as saturated porous media. The excess pore pressure due to fast filling process is derived using the classical one-dimensional consolidation theory by assuming the thickness of the filled soil to increase linearly. Meanwhile, another part of the excess pore pressure induced by the soil contraction under shear deformation is derived by using the modified Cam-clay model. Then the effective stress is obtained by subtracting the pore pressure, i.e., the static pore pressure and the two parts of the excess pore pressure, from the total stress. The undrained shear strength can be expressed by the effective friction angle and the effective stress. Finally, the landslide is simulated using the material point method by assuming an undrained run-out process in which the soil strength keeps constant. The destructive effect of the sliding soil on the buildings is also analyzed. The proposed theory can be used to explain the extraordinary flow ability of the soil satisfactorily.
引文
[1]百度百科.12·20深圳山体滑坡[Z].2016.(Baidu encyclopedia.12·20 Shenzhen landslide[Z].2016.(in Chinese))
[2]人民网.安监总局局长:深圳“12·20”滑坡事故已被认定为重大安全生产责任事故[Z].2016.(People's Daily Online.The country's top work safety official:12·20 Shenzhen landslide is a serious production accident[Z].2016.(in Chinese))
[3]调查:深圳山体滑坡大调查,http://www.iqiyi.com/v_19rrkg3vpg.html[Z].2016.(Survey:Shenzhen landslide survey,http://www.iqiyi.com/v_19rrkg 3vpg.html[Z].2016.(in Chinese))
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[5]DAVIES T R H.Spreading of rock avalanche debris by mechanical fluidization[J].Rock Mechanics,1982,15(1):9–24.
[6]OKURA Y,KITAHARA H,SAMMORI T,et al.The effects of rockfall volume on runout distance[J].Engineering Geology,2000,58(2):109–124.
[7]SASSA K.Geotechnical model for the motion of landslides[C]//Proceedings of the 5th International Symposium on Landslides.Lausanne,1988:37–55.
[8]ALONSO E E,PINYOL N M,PUZRIN A M.Geomechanics of failures.advanced topics[M].Springer Netherlands,2010.
[9]COLLINS G S,MELOSH H J.Acoustic fluidization and the extraordinary mobility of sturzstroms[J].Journal of Geophysical Research(Solid Earth),2003,108(B10).
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[12]ZHANG X,KRABBENHOFT K,SHENG D,et al.Numerical simulation of a flow-like landslide using the particle finite element method[J].Computational Mechanics,2015,55(1):167–177.
[13]孙玉进,宋二祥.大位移滑坡形态的物质点法模拟[J].岩土工程学报,2015(7):1218–1225.(SUN Yu-jin,SONG Er-xiang.Simulation of large-displacement landslide by material point method[J].Chinese Journal of Geotechnical Engineering,2015(7):1218–1225.(in Chinese))
[14]SUN Yu-jin,YANG Jun,SONG Er-xiang.Runout analysis of landslides using material point method[J].Earth and Environmental Science,2015,26(1):2014.
[15]李广信.高等土力学[M].北京:清华大学出版社,2004.(LI Guang-xin.Advanced soil mechanics[M].Beijing:Tsinghua University Press,2004.(in Chinese))
[16]GIBSON R E.The progress of consolidation in a clay layer increasing in thickness with time[J].Géotechnique,1958,8(4):171–182.
[17]姚仰平,万征,杨一帆.饱和黏土不排水剪切的热破坏[J].岩土力学,2011,32(9):2561–2569.(YAO Yang-ping,WAN Zheng,YANG Yi-fan,et al.Thermal failure for saturated clay under undrained condition[J].Rock and Soil Mechanics,2011,32(9):2561–2569.(in Chinese))
[18]SONG Er-xiang.Elasto-plastic consolidation under steady and cyclic loads[D].Delft:Delft University of Technology,1990.
[2]人民网.安监总局局长:深圳“12·20”滑坡事故已被认定为重大安全生产责任事故[Z].2016.(People's Daily Online.The country's top work safety official:12·20 Shenzhen landslide is a serious production accident[Z].2016.(in Chinese))
[3]调查:深圳山体滑坡大调查,http://www.iqiyi.com/v_19rrkg3vpg.html[Z].2016.(Survey:Shenzhen landslide survey,http://www.iqiyi.com/v_19rrkg 3vpg.html[Z].2016.(in Chinese))
[4]KENT P.The transport mechanism in catastrophic rock falls[J].The Journal of Geology,1966,74(1):79–83.
[5]DAVIES T R H.Spreading of rock avalanche debris by mechanical fluidization[J].Rock Mechanics,1982,15(1):9–24.
[6]OKURA Y,KITAHARA H,SAMMORI T,et al.The effects of rockfall volume on runout distance[J].Engineering Geology,2000,58(2):109–124.
[7]SASSA K.Geotechnical model for the motion of landslides[C]//Proceedings of the 5th International Symposium on Landslides.Lausanne,1988:37–55.
[8]ALONSO E E,PINYOL N M,PUZRIN A M.Geomechanics of failures.advanced topics[M].Springer Netherlands,2010.
[9]COLLINS G S,MELOSH H J.Acoustic fluidization and the extraordinary mobility of sturzstroms[J].Journal of Geophysical Research(Solid Earth),2003,108(B10).
[10]KOERNER H J.Flow mechanisms and resistances in the debris streams of rock slides[J].Bulletin of the International Association of Engineering Geology,1977,16(1):101–104.
[11]张明,殷跃平,吴树仁.高速远程滑坡–碎屑流运动机理研究发展现状与展望[J].工程地质学报,2010(6):805–817.(ZHANG Ming,YIN Yue-ping,WU Shu-ren,et al.Development status and prospects of studies on kinematics of long runout rock avalanches[J].Journal of Engineering Geology,2010(6):805–817.(in Chinese))
[12]ZHANG X,KRABBENHOFT K,SHENG D,et al.Numerical simulation of a flow-like landslide using the particle finite element method[J].Computational Mechanics,2015,55(1):167–177.
[13]孙玉进,宋二祥.大位移滑坡形态的物质点法模拟[J].岩土工程学报,2015(7):1218–1225.(SUN Yu-jin,SONG Er-xiang.Simulation of large-displacement landslide by material point method[J].Chinese Journal of Geotechnical Engineering,2015(7):1218–1225.(in Chinese))
[14]SUN Yu-jin,YANG Jun,SONG Er-xiang.Runout analysis of landslides using material point method[J].Earth and Environmental Science,2015,26(1):2014.
[15]李广信.高等土力学[M].北京:清华大学出版社,2004.(LI Guang-xin.Advanced soil mechanics[M].Beijing:Tsinghua University Press,2004.(in Chinese))
[16]GIBSON R E.The progress of consolidation in a clay layer increasing in thickness with time[J].Géotechnique,1958,8(4):171–182.
[17]姚仰平,万征,杨一帆.饱和黏土不排水剪切的热破坏[J].岩土力学,2011,32(9):2561–2569.(YAO Yang-ping,WAN Zheng,YANG Yi-fan,et al.Thermal failure for saturated clay under undrained condition[J].Rock and Soil Mechanics,2011,32(9):2561–2569.(in Chinese))
[18]SONG Er-xiang.Elasto-plastic consolidation under steady and cyclic loads[D].Delft:Delft University of Technology,1990.