ISSN 1003-8035 CN 11-2852/P

    甘肃舟曲县江顶崖滑坡抗滑桩变形监测与治理效果分析

    Analysis of monitoring and treatment effect of anti-sliping piles for the landslide at Jiangdingya, Zhouqu County

    • 摘要: 为研究白龙江流域舟曲段堆积体滑坡治理中抗滑桩的承载特性及其治理效果,以舟曲江顶崖滑坡治理工程为对象,在滑坡前缘中部和两侧的3根抗滑桩迎滑面和背滑面的中部与角部分别布置钢筋应力计,获取现场3 a的动态数据,并通过ABAQUS对治理后的滑坡体进行数值模拟分析。结果表明:(1)当前桩身钢筋的应力增长速率较施工结束时明显减缓,低于抗拉强度设计值,且钢筋仍处于弹性工作状态,这表明抗滑桩对滑坡的治理效果较好;(2)江顶崖滑坡多级滑面的滑动导致抗滑桩不仅受到滑坡推力的作用,其表面还受到了岩土体的摩擦力作用,具体表现为3根试验桩的迎滑面与背滑面两侧的钢筋在5 m、10 m、20 m深度处均主要表现为拉应力,这与现行规范抗滑桩设计时截面前后两侧拉压应力状态相反的情况不符,是因为应力具有叠加效应,当摩擦力对桩产生的拉应力大于弯曲压应力时,会使得该侧的钢筋应力整体表现为拉应力,从而出现抗滑桩前后两侧钢筋均受拉的应力状态;(3)治理工程完工后,通过数值模拟对滑坡的水平位移进行分析,发现滑坡的最大水平位移为33.93 mm,表明滑坡支护结构加固作用较好,滑坡体在经过加固后处于基本稳定状态,且桩土之间形成了新的变形协调。研究成果可为该区域堆积体滑坡治理工程的设计提供科学依据。

       

      Abstract: In order to study the bearing characteristics and treatment effects of anti-sliping piles in the treatment of accumulation landslides in the Bailong River Basin, Zhouqu section, Zhouqu Jiangdingya landslide treatment project was taken as the object. Steel bar stress gauges were arranged at the middle and corners of the upstream and downstream sliding surfaces of the three anti-sliping piles at the front edge of the landslide, and dynamic data from three years were obtained on site. Numerical simulation analysis was conducted on the treated landslide using ABAQUS. The results show that: (1) The stress growth rate of pile reinforcement has significantly slowed down compared to the end of construction, which is lower than the design value of tensile strength, and the rebar is still in an elastic working state, indicating that the treatment effect of anti-sliding piles on the landslide control is good; (2) The multi-level sliding of Jiangdingya landslide causes the anti-sliding piles to not only be effected by the landslide thrust, but also by the frictional force of the rock and soil body. Specifically, the steel bars on both sides of the sliding and backing surfaces of the three test piles is mainly tensile stress at depths of 5 m, 10 m and 20 m, which is opposite to the stress state of tension and compression on both sides of the section when designing anti-sliding piles according to current standards. This discrepancy is due to the superposition effect of stress. When the tensile stress generated by friction force on the pile is greater than the bending compressive stress, the overall stress of the steel bar on that side will be tensile stress. (3) After the completion of the treatment project, the horizontal displacement of the landslide is analyzed by numerical simulation. It was found that the maximum horizontal displacement of the landslide was 33.93 mm, indicating that the reinforcement of the landslide support structure is good. The landslide body is in a stable state after reinforcement, and a new deformation coordination between piles and soil has been formed. The research results can provide scientific basis for the design of accumulation landslide control project in this area.

       

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