摘要
为深入探索库水复活型滑坡的破坏模式和力学机制,设计研发新型试验装置,装置主体是由若干渗透盒构成的分段式滑面,能够模拟各种几何形态的滑动面。通过向不同区段的渗透盒注水,可模拟滑带土分阶段饱水软化,实现库水位上升条件下相邻滑块间的牵引滑动过程。采用传感元件、数码摄像以及数字图像处理等测试手段,获取滑带土体积含水率、孔隙水压力、坡面水平位移的变化规律以及后缘面演化特征,并探讨滑坡体失稳破坏模式。结果表明:滑带土饱水后抗剪强度大幅度下降是滑坡发生的重要条件,滑动面处的孔压变动是激发老滑坡复活的重要诱因;滑带处孔隙水压力的增大与滑坡位移的增大是同时发生的,滑带土强度衰减与滑体变形具有良好的相关关系;坡面变形区域分为强、弱变形区和牵引区3部分,坡面变形为1~1.5倍的失稳滑带长度;随着失稳滑带长度增加,坡面变形区域变大,对后侧稳定坡体的牵引变形影响变小;后缘破裂面多呈折线型滑面形态,后缘破裂面倾角试验值受失稳滑段位置和滑体厚度影响显著。研究结果为库区滑坡灾变机制的认识和治理提供重要依据。
To further explore the failure mode and mechanical mechanism of reservoir-reactivated landslide,a new test device was designed and developed,the main body of which is composed of several permeable boxes,and it can simulate sliding surfaces with different geometric shapes.The sliding zone can be multi-stage softened by injecting water into different permeable boxes,so that the retrogressive-slide process between adjacent sliders caused by the rise of the reservoir water level can be realized.Through the techniques of digital photography,digital image processing,and transducers measurement,a series of important test data were obtained,such as volume water content,pore water pressure,horizontal displacement of slope,and evolution characteristics of the trailing edge surface.Moreover,the failure mode of the landslide body was discussed.Test results show that the significant decrease in shear strength of sliding zone soil after saturation was an important reason for the occurrence of landslide.The pore pressure variation at the sliding surface was the main inducing factor for the revival of the old landslide.The increase in pore water pressure at the sliding zone occurred simultaneously with the increase in the landslide displacement,and there was a good correlation between the strength degradation of sliding zone soil and the deformation of sliding body.The slope deformation area was divided into three parts:strong and weak deformation area and traction area.The slope deformation range was about 1 to 1.5 times the length of the unstable sliding zone.With the increase in the length of unstable sliding zone,the deformation zone of the slope increased,and the influence on the traction deformation of the back stable slope decreased.The trailing edge rupture surfaces were mostly in the shape of folded slip surface,and the experimental values of the inclination angle of the trailing edge surface were significantly affected by the position of the unstable sliding section and the thickness of the sliding body.The research results provide important basis for the understanding and controlling of landslide disasters in reservoir area.
作者
孙立娟
崔凯
王溢轩
SUN Lijuan;CUI Kai;WANG Yixuan(College of Transportation Science and Engineering,Jilin Jianzhu University,Changchun 130118,China;Key Laboratory of High-Speed Railway Engineering(Southwest Jiaotong University),Ministry of Education,Chengdu 610031,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《哈尔滨工业大学学报》
EI
CAS
CSCD
北大核心
2021年第11期162-170,共9页
Journal of Harbin Institute of Technology
基金
吉林省教育厅“十四五”科学技术研究项目(JJKH20210261KJ)
国家自然科学基金(41572245)。
关键词
复活型滑坡
分段式滑面
牵引式滑动
数字图像处理
坡面变形区
后缘破裂面倾角
reactivated landslide
sectional sliding surface
retrogressive slide
digital image processing
slope deformation zone
inclination angle of the trailing edge
