降雨入渗条件下框架锚杆支护边坡稳定性与变形分析  

Stability and deformation analysis of slope supported by frame anchors under rainfall infiltration

作　　者：叶帅华[1,2] 唐宁 李京榜 YE Shuai-hua;TANG Ning;LI Jing-bang(Western Engineering Research Center of Disaster Mitigation in Civil Engineering of Ministry of Education,Lanzhou University of Technology,Lanzhou 730050,Gansu,China;Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province,Lanzhou University of Technology,Lanzhou 730050,Gansu,China;College of Civil Engineering,Lanzhou Institute of Technology,Lanzhou 730050,Gansu,China)

机构地区：[1]兰州理工大学西部土木工程防灾减灾教育部工程研究中心,甘肃兰州730050 [2]兰州理工大学甘肃省土木工程防灾减灾重点实验室,甘肃兰州730050 [3]兰州工业学院土木工程学院,甘肃兰州730050

出　　处：《地基处理》2024年第1期77-89,共13页Journal of Ground Improvement

基　　金：国家自然科学基金(52168050,51768040,51508256);2023年甘肃省高校青年博士支持项目(2023QB-052);甘肃省高校青年博士基金(2023QB-048)。

摘　　要：降雨引起的滑坡问题一直是工程界所面临的难题,也是工程界研究的热点问题。国内外学者针对降雨引起的滑坡问题展开了多方面的研究,框架预应力锚杆作为一种新型支挡结构,对降雨引起的滑坡问题有很好的治理效果。因此本文在前人研究基础上,针对降雨入渗引起的边坡基质吸力、位移、稳定性问题进行了研究。结合实际工程,通过数值模拟软件PLAXIS3D建立三维有限元模型,首先对降雨入渗条件下框架锚杆支护边坡的基质吸力、位移和稳定性进行分析,然后分别考虑降雨时间、降雨强度和地下水位对边坡加固前后基质吸力、边坡位移和稳定性的影响情况。结果表明:(1)基质吸力在降雨前随坡高呈线性增加,降雨后基质吸力迅速降低,边坡最大位移值发生在边坡坡脚附近区域;(2)边坡基质吸力随降雨时间增大而减小,边坡表面基质吸力下降得更快;(3)降雨强度越大,基质吸力下降得越快,边坡位移也随之增大,边坡安全系数降低;(4)地下水位越高,边坡基质吸力下降得越快,边坡位移增加越快,边坡安全系数越小。Rainfall-induced landslides have persistently posed challenges in engineering,constituting a focal point for research endeavors in the discipline.The frame prestressing anchor,serving as an innovative support structure,demonstrates a beneficial influence on rainfall-induced landslides.Therefore,this work studies the matric suction,displacement and stability of slope caused by rainfall infiltration.Combined with the actual project,a three-dimensional finite element model was established by using the numerical simulation software PLAXIS 3D.Firstly,the matric suction,displacement and stability of the frame anchor supporting slope under the condition of rainfall infiltration were analyzed.Then,the effects of rainfall time,rainfall intensity and groundwater level on matric suction,slope displacement and stability before and after slope reinforcement were considered respectively.The findings indicate that:(1)matric suction exhibits a linear increase with slope height before rainfall,followed by a rapid decline after rainfall,with maximum slope displacement occurring proximal to the slope toe.(2)Matric suction of the slope diminishes with an increase in rainfall duration,and the matric suction of the slope surface experiences a swifter reduction.(3)Elevated rainfall intensity correlates with an accelerated decrease in matric suction,heightened slope displacement,and a diminished slope safety factor.(4)An elevated groundwater level is associated with a hastened reduction in slope matric suction,an expedited increase in slope displacement,and a diminished slope safety factor.

关 键 词：降雨入渗 地下水 孔隙水压力 框架锚杆 基质吸力 边坡稳定性 

分 类 号：TU43[建筑科学—岩土工程]