朱凌, 裴向军, 崔圣华, 孟祥瑞. 2018: 基于动三轴试验的大光包滑坡层间错动带动力特性研究. 工程地质学报, 26(3): 647-654. DOI: 10.13544/j.cnki.jeg.2017-225
    引用本文: 朱凌, 裴向军, 崔圣华, 孟祥瑞. 2018: 基于动三轴试验的大光包滑坡层间错动带动力特性研究. 工程地质学报, 26(3): 647-654. DOI: 10.13544/j.cnki.jeg.2017-225
    ZHU Ling, PEI Xiangjun, CUI Shenghua, MENG Xiangrui. 2018: TRIAXIAL TESTS FOR DYNAMIC CHARACTERISTICS OF THE BEDDING FAULT MATERIAL WITHIN BASAL LAYER OF DAGUANGBAO LANDSLIDE. JOURNAL OF ENGINEERING GEOLOGY, 26(3): 647-654. DOI: 10.13544/j.cnki.jeg.2017-225
    Citation: ZHU Ling, PEI Xiangjun, CUI Shenghua, MENG Xiangrui. 2018: TRIAXIAL TESTS FOR DYNAMIC CHARACTERISTICS OF THE BEDDING FAULT MATERIAL WITHIN BASAL LAYER OF DAGUANGBAO LANDSLIDE. JOURNAL OF ENGINEERING GEOLOGY, 26(3): 647-654. DOI: 10.13544/j.cnki.jeg.2017-225

    基于动三轴试验的大光包滑坡层间错动带动力特性研究

    TRIAXIAL TESTS FOR DYNAMIC CHARACTERISTICS OF THE BEDDING FAULT MATERIAL WITHIN BASAL LAYER OF DAGUANGBAO LANDSLIDE

    • 摘要: 大光包滑坡是2008年汶川地震触发的最大规模滑坡, 平硐揭示该滑坡滑带形成于糜棱质化、泥化的层间错动带, 且地下水从该错动带渗出。为分析强震过程饱水错动带材料动力特性, 本文作者在平硐内取不同层位错动带材料C1(粉粒为主)、C2(粉黏粒为主)和C3(砂粒为主), 室内进行了系列动三轴试验, 得出如下结论:(1)在设计动荷载(40 kPa、60 kPa和80 kPa)下, C1、C2孔压增长缓慢, 没有液化; 而C3孔压增长迅速, 5%应变时动孔压增长到围压值, 试样液化。(2)试样动剪应力值与振动次数关系较大; 随着振次增加C3动剪应力值明显减小, 而C1、C2动剪应力小幅度减小; (3)在相同动应变下, C3动应力和动弹性模量最大, 动阻尼比最小; 而C2动应力和弹性模量最小, 动阻尼比最大。结果表明, 大光包层间错动带在地震中可能发生液化, 从而导致错动带抗剪强度骤然降低, 滑坡快速启动。

       

      Abstract: Daguangbao landslide is the largest landslide triggered by the 2008 Wenchuan earthquake.The sliding zone formed in a bedding fault which was composed of the material of mylonite and mud.The groundwater could be found flowing out.To analyze the process of earthquake dynamic characteristics of the saturated fault material, a series of dynamic triaxial tests were conducted on the three samples C1, C2 and C3 which were taken from an exploratory tunnel in the fault.The results show that:(1)Under dynamic load(40 kPa, 60 kPa, and 80 kPa), C1 and C2 pore pressure shows slow growth, dynamic pore pressure is still far less than the confining pressure when achieving strain 5%, and the samples have no liquefactive.C3 dynamic pore pressure is growing rapidly.When strain achieves 5%, dynamic pore pressure is equal to the confining pressure, and the sample is liquefied.(2)The dynamic strength and strain relations of sample are close.With the increase of strain, under the same cycles C3 dynamic shear stress decreases obviously, while C1 and C2 have modest increase.(3)When the dynamic strain is certain, C3 dynamic stress and the elastic modulus are the biggest, and its dynamic damping ratio is the least.C2 dynamic stress and the elastic modulus are the least, and its dynamic damping ratio is the largest.It can be concluded that the fault material might be liquefied during the 2008 Wenchuan earthquake resulted in rapidly decreasing of the shear strength of the bedding fault.The Daguangbao landslide might be initiated suddenly.

       

    /

    返回文章
    返回