降雨作用下缓倾堆积层滑坡失稳机制与工程效果评价  

Instability Mechanism and Engineering Effect Evaluation on Gently Tipping Deposit Landslide Under Rainfall

作　　者：周文皎 徐勇 李知军 范家玮 ZHOU Wen-jiao;XU Yong;LI Zhi-jun;FAN Jia-wei(Railway Engineering Research Institute of China Academy of Railway Sciences Co.,Ltd.,Beijing 100081,China;State Key Laboratory of Track Technology for High Speed Railway,Beijing 100081,China;Yunnan Construction and Investment Holding Group Co.,Ltd.,Kunming,Yunnan 650000,China)

机构地区：[1]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [2]高速铁路轨道系统全国重点实验室,北京100081 [3]云南省建设投资控股集团有限公司,云南昆明650000

出　　处：《公路交通科技》2024年第8期86-95,共10页Journal of Highway and Transportation Research and Development

基　　金：中国铁道科学研究院集团有限公司基金项目(2022YJ126);云南省交通运输厅科技计划项目(云交科教2018-35)。

摘　　要：滑坡灾变机理模式与整治工程对策模型的针对性研究较少。以滇西北地区某高速公路滑坡为对象,采用宏观迹象调查、滑坡现状稳定性评价、滑带强度指标反算与数值分析计算相结合的方法对路堑边坡开挖诱发滑坡的灾变全过程进行了系统研究,分析了该边坡滑坡的灾变机理并评价了其整治工程效果。结果表明:受路堑边坡施工开挖卸荷影响,坡体应力场发生调整,坡体中上部浅表层与路基下部土岩界面处出现应力松弛现象,坡脚局部出现应力集中现象,并逐步扩大形成塑性区,最终形成了浅表层贯通松弛区和沿土岩界面的潜在滑裂面;受持续强降雨作用,地表水下渗坡体,土体含水量增加,土岩界面岩土体软化、强度降低,边坡浅表层应力松弛区与潜在滑裂面发生屈服变形,并不断向上和向下发展直至贯通,导致路堑边坡滑坡;滑坡整治工程采用多级刷方卸载、锚索框架梁、锚索抗滑桩和截排水沟等综合治理措施;整治工程实施后坡体处于稳定状态,满足规范要求,效果良好;滑坡病害演化与整治工程历经起始、路堑开挖、变形破坏、工程整治4个主要工程阶段,对比各阶段稳定性计算结果与宏观迹象调查结果,稳定性计算结果与滑坡各阶段变形、整治效果相符。There are few targeted studies based on the landslide disaster mechanism mode and landslide control engineering countermeasure model.This article takes an expressway landslide in Northwestern Yunnan as the object.The combination of macroscopic evidence investigation,landslide stability evaluation,sliding zone strength index reverse calculation,and numerical analysis calculation was adopted to systematically study the entire process of landslide induced by cutting slope excavation.The disaster mechanism of slope landslide was analyzed,and the effectiveness of its remediation engineering was evaluated.The result indicates that due to the influence of excavation and unloading during the road cutting slope construction,the stress field of slope body is adjusted.The stress relaxation occurs at the interface between the shallow surface layer in slope upper part and the soil rock interface at roadbed lower part.The stress concentration occurs locally at the slope foot,gradually expanding to form the plastic zone,ultimately forming the potential sliding surface that connects the relaxation zone in the shallow surface layer and the soil rock interface.Affected by sustained heavy rainfall,the surface water infiltrates the slope,increasing the soil moisture content and softening the rock and soil at the soil rock interface,resulting in a decrease in strength.The shallow surface stress relaxation zone of slope and the potential sliding surfaces undergo yield deformation,continuously developing upwards and downwards until they are connected,leading to cutting slope sliding.The landslide control engineering adopts comprehensive measures,e.g.,multi-level brushing and unloading,anchor frame beams,anchor anti slip piles,and interception and drainage ditches.After the rectification engineering implementation,the slope is in a stable state,meeting the regulatory requirements and achieving good results.The evolution and remediation of landslide disease have gone through the main engineering stages of initiation,excavation,deformatio

关 键 词：道路工程 滑坡灾变机理 数值分析 边坡卸荷 路堑开挖 

分 类 号：U416.1[交通运输工程—道路与铁道工程]