摘要
双排抗滑桩后侧滑坡推力分布是其设计中要考虑的关键要素之一。针对一大型基岩-覆盖层式滑坡,进行四组不同后排桩布设方式的双排桩加固滑坡的室内物理模型试验,通过采用坡体外注水,经过特定通道渗入滑带的方法来模拟强降雨条件对滑带的软化效应,测得不同工况下两排桩后侧滑坡推力分布特征,并通过FLAC^(3D)数值模拟方法对试验结果进一步验证。试验结果表明,后、前排桩上坡体压力均呈两端小、中间大的抛物线型分布模式且峰值点相对靠近滑面位置;桩位不变时,后桩后侧坡体压力峰值随沉埋深度增大而减小且峰值点位置上移,前桩后侧坡体压力峰值随后桩沉埋深度增大而增大,但峰值点位置无明显变化;滑带软化效应并不改变双排桩上推力分布模式,但会增大前、后排桩后侧坡体压力,且相比桩顶和底部,桩身中间部分坡体压力增加幅度较大;注水软化前后,后、前排桩上坡体压力分别增大约14.3%~21.4%与17.9%~24.8%。
Distribution pattern of thrust force on double-row stabilizing piles is one of the essential factors for the design of stabilizing piles.For a bedrock-overburden landslide strengthened with double-row stabilizing piles,four sets of laboratory physical model test are conducted considering various rear-row pile configurations.In particular,slip surface softening effect due to heavy rainfall is physically simulated using external water injection and infiltration into the shear band through a special channel.Distribution characteristics of the landslide thrust on the two piles are measured,which is further verified by a numerical simulation method FLAC^(3D).The test results show that the thrusts on the rear and fore piles present a parabolic distribution pattern,and the location with peak value is relatively close to the slip surface.If the pile location remains unchanged,the peak value of the thrust force behind the rear pile decreases with the increase of its embedded depth and the position with peak value moves upward;while the peak value of the thrust behind the fore pile increases with the embedded depth of the rear pile top,and the position with peak value changes unobviously.The slip surface softening effect does not change the distribution pattern of the thrust forces on piles,but it can increase the thrusts behind the piles;compared with the top and bottom of the piles,the increase of the thrust in the middle part of the piles is relatively larger.The thrust forces on the rear and fore piles under external water injection are about 14.3%~21.4% and 17.9%~24.8% higher than those before the softening action,respectively.
作者
闫玉平
肖世国
YAN Yuping;XIAO Shiguo(Department of Geological Engineering,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;Key Laboratory of High-speed Railway Engineering,Ministry of Education(Southwest Jiaotong University),Chengdu,Sichuan 610031,China)
出处
《中国地质灾害与防治学报》
CSCD
2022年第2期79-87,共9页
The Chinese Journal of Geological Hazard and Control
基金
国家自然科学基金项目(51578466)。
关键词
滑坡
双排桩
推力分布
物理模型试验
滑面软化效应
landslides
double-row stabilizing piles
thrust distribution
physical model test
slip surface softening effect