人工开挖高边坡支护结构加固作用数值模拟分析  

Numerical simulation analysis on reinforcement mechanism of support structure for artificial excavation high slope

作　　者：李坚 周卫 杨龙伟 江强强 陈涛 LI Jian;ZHOU Wei;YANG Longwei;JIANG Qiangqiang;CHEN Tao(CCTEG Wuhan Engineering Company,Wuhan 430000,China)

机构地区：[1]中煤科工集团武汉设计研究院有限公司,湖北武汉430000

出　　处：《水利水电快报》2023年第3期51-57,共7页Express Water Resources & Hydropower Information

基　　金：国家自然科学基金“水库环境下多滑面滑坡渐进破坏机制与动态稳定性研究”(42007279)。

摘　　要：为提升人工开挖高边坡的稳定性,以湖北武汉森林大道挖方高边坡为研究对象,利用强度折减法,通过数值模拟研究了未开挖、开挖未支护、抗滑桩支护和肋柱式预应力锚索+抗滑桩支护等4种工况下的边坡稳定性、变形特征及支护结构作用机理。结果表明:①边坡开挖后稳定系数大幅度下降,抗滑桩能有效阻止坡脚土体的变形,板肋式锚索对抗滑桩以上的土体加固效果较好,各工况的稳定性由大到小依次为未开挖边坡、肋柱式预应力锚索+抗滑桩支护边坡、抗滑桩支护边坡、未支护边坡;②抗滑桩主要受剪力作用,悬臂段剪力为负,嵌固段为正,最大值在一级坡坡脚附近,其弯矩基本为正值,最大值处距桩顶约13 m;③在肋柱受力方面,锚固点处剪力最大,近似于集中点荷载,弯矩大小接近0,锚固点中间段肋柱剪力由受压向受拉状态转换,在中点附近达到最大拉剪应力,弯矩则先为正值再变为负值。In order to improve the stability of excavated slope,the excavation high slope in Forest Avenue,Wuhan,Hubei was taken as the research object.The strength reduction method was used,and the stability and deformation characteristics of the slope and the action mechanism of the support structure under 4 different working conditions,such as the pre-excavation slope,the unsupported slope,the anti-slide pile support slope and the ribbed column prestressed anchor cable+anti-slide pile support slope,were studied based on numerical simulation method.The results showed that:①The stability coefficient decreased significantly after slope excavation,and the anti-slide pile could effectively prevent the deformation of the soil at the slope toe.The plate rib anchor cable had good reinforcement effect on the soil above the anti-slide pile.The slope stability in each working conditions decreased as follows:unexcavated slope,ribbed column prestressed anchor cable+anti-slide pile support slope,anti-slide pile support slope,unsupported slope;②The anti-slide pile was mainly affected by shear force.The shear force of the cantilever section was negative,and that of the embedded section was positive.The maximum value was near the toe of the first-grade slope,and its bending moment was positive.The maximum value was about 13 m from the pile top;③In terms of the stress of the rib column,the shear force at the anchor point was the largest,which was similar to the concentrated point load,and the bending moment was close to 0.The shear force of the middle section of the anchor point in the rib column was transformed from compression to tension,the maximum tensile and shear stress was reached near the midpoint,and the bending moment was first positive and then changes to negative.

关 键 词：挖方高边坡 支护结构 强度折减法 稳定性分析 数值模拟 

分 类 号：U416.14[交通运输工程—道路与铁道工程]