层状反倾边坡破坏机制及NPR锚索控制效果物理模型试验  

Physical model experiment on failure mechanism and NPR anchor cable control effect of layered counter-tilt slope

作　　者：陶志刚[1,2] 任树林 郝宇 李强 付强[4] 何满潮[1,2] TAO Zhi-gang;REN Shu-lin;HAO Yu;LI Qiang;FU Qiang;HE Man-chao(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology Beijing,Beijing 100083,China;School of Mechanics and Civil Engineering,China University of Mining and Technology Beijing,Beijing 100083,China;Production Technology Department of Inner Mongolia Taiping Mining Co.,Ltd.,Bayan Nur,Inner Mongdia 015300,China;China National Gold Group Hong Kong Co.,Ltd.,Beijing 100011,China)

机构地区：[1]中国矿业大学(北京)深部岩土力学与地下工程国家重点实验室,北京100083 [2]中国矿业大学(北京)力学与建筑工程学院,北京100083 [3]内蒙古太平矿业有限公司生产技术部,内蒙古巴彦淖尔015300 [4]中国黄金集团香港有限公司,北京100011

出　　处：《岩土力学》2021年第4期976-990,共15页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.41941018);中央高校基本科研业务费专项资金(No.2015QB02)。

摘　　要：以内蒙古长山壕露天矿区大规模倾倒失稳反倾边坡为工程背景。首先基于相似理论构建层状反倾边坡地质概化物理模型,开展在未加固、普通锚索加固(PR锚索)及恒阻大变形锚索加固(NPR锚索)3种不同工况条件下边坡控制效果物理模型试验。然后使用红外热成像系统、应变监测系统和数字散斑位移测量系统,对反倾边坡开挖试验全过程的温度场、应变场和位移场进行综合监测。最后,研究层状反倾边坡变形特征和失稳机制,对比分析不同加固对策下的加固效果。研究结果表明:层状反倾边坡变形过程具有明显的"叠合悬臂梁"变形特征,其倾倒机制主要表现为岩层初始裂纹产生、岩层裂纹发育以及滑动面贯通边坡失稳3个阶段。PR锚索在边坡开挖过程中断裂失效,无法抵抗边坡大变形失稳。NPR锚索具有高恒阻、大变形以及吸收能量的超强特性,有效防止反倾边坡倾倒失稳的发生,为边坡工程加固提供了一种新的思路。Taking the large-scale toppling failure counter-tilt slope in Changshanhao open-pit mine in Inner Mongolia as engineering background,a layered counter-tilt slope geological generalized physical model was constructed based on similar theory.Physical model tests were performed under three different conditions:unreinforced,ordinary PR anchor cable reinforcement,and constant resistance and large deformation(NPR)anchor cable reinforcement.Then infrared thermal imaging system,strain monitoring system and digital speckle displacement measurement system were used comprehensively to monitor the temperature field,strain field and displacement field respectively during the entire counter-tilt slope excavation test.Finally the deformation characteristics and instability mechanism of layered counter-tilt slope were investigated,and the reinforcement effects under different reinforcement measures were compared and analyzed.The research results show that the deformation process of counter-tilt slope has obvious deformation characteristics of"superimposed cantilever beam".Its toppling mechanism is mainly manifested in three stages:initial crack formation,crack development,and sliding surface penetrating and slope instability.The PR anchor cable failed during the excavation and could not resist the large deformation of the slope.In contrast,the NPR anchor cable has the characteristics of high constant resistance,large deformation and energy absorption,which can effectively prevent the occurrence of counter-tilt slope instability and provide a new way for slope engineering reinforcement.

关 键 词：反倾边坡 模型试验 加固对策 NPR锚索 倾倒变形 

分 类 号：TU457[建筑科学—岩土工程]