摘要
为探究岩质地层新型抗浮结构--牛腿抗浮结构的工作特性,基于其实际边界条件,设计剪切试验装置,开展室内剪切试验,分析其剪切力学特性,借助数值散斑系统与声发射系统,探究其变形演化过程、剪切破坏模式与损伤演化规律。研究表明:(1)根据剪切强度与变形特征,可将结构剪切过程划分为初始压密段、近似线弹性变形段、初始微裂纹萌生与扩展段、缓慢压剪非线性变形段、应力脆性跌落段、塑性流动变形段这6个阶段。(2)随牛腿角度减小,峰值剪切应力τp和峰值剪切位移up呈先增大后减小的“抛物线”趋势,随牛腿高度增大,峰值剪切应力τp和峰值剪切位移up近似呈“反比例函数”趋势增大。(3)破坏由某一裂缝易发区开始,多易发区相继破坏,最终贯通,呈现以左侧压剪、右侧拉剪、交界面脱黏滑移为主,局部细小裂缝的剪切破坏模式。(4)随牛腿角度增大,破坏模式从沿交界面脱黏向沿材料内部贯通破坏转变,随牛腿高度增大,破坏模式从右上角快速拉坏向沿交界面脱黏、牛腿处向上下侧反向起裂转变。(5)随牛腿角度减小,声发射阶段Ⅰ时长几乎相同,阶段Ⅱ时长先增大后减小,声发射活性先增大后减小;随牛腿高度增大,声发射阶段Ⅰ时长几乎相同,阶段II时长逐渐增大,声发射活性逐渐增大。研究结论有助于从极限状态角度指导牛腿抗浮结构设计。
In order to explore the working characteristics of a new type of anti-floating structure in rock layer,that is,the ox leg anti-floating structure,based on the actual boundary conditions of the structure,the shear test device was designed and the indoor shear test was carried out to analyse the shear failure characteristics.The deformation evolution process,shear failure mode and damage evolution law were investigated by digital image correlation method and acoustic emission method.The results show that:(1)According to the characteristics of strength and deformation,the structural shear process can be divided into initial compaction stage,approximate linear elastic deformation stage,initial microcrack initiation and propagation stage,slow compression shear nonlinear deformation stage,stress brittle drop stage and plastic flow deformation stage.(2)The peak shear stressτp and peak shear displacement up show a“parabolic”trend of first increasing and then decreasing with the decrease of the leg angle,and show an approximately“inverse proportional function”trend of increasing with the increase of the leg height.(3)The failure starts from one fracture-prone area,and then successively breaks through in multiple fractureprone areas.The shear failure mode is mainly characterized by compression shear on the left side,tension shear on the right side,and slip on the interface,with local small cracks.(4)With the increase of the leg angle,the failure mode changes from the slip along the interface to the penetrating failure along the interior of the material.With the increase of the leg height,the failure mode changes from the rapid pulling at the upper right corner to the slip along the interface and the reverse cracking at the leg to the upper and lower sides.(5)As the leg angle decreases,the duration of AE phase I is almost the same,while the duration of AE phase II increases first and then decreases,and the AE activity increases first and then decreases.As the leg angle increases,the duration of AE phase I is almost the same,and the duration of AE phase II increases gradually,and the AE activity increases gradually.The conclusion is helpful to guide the design of the ox leg anti-floating structure from limit state.
作者
王林枫
刘新荣
周小涵
刘鹏
李隆平
赵顺磊
WANG Linfeng;LIU Xinrong;ZHOU Xiaohan;LIU Peng;LI Longping;ZHAO Shunlei(School of Civil Engineering,Chongqing University,Chongqing 400045,China;National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area of the Ministry of Education,Chongqing University,Chongqing 400045,China;China Railway Major Bridge Reconnaissance and Design Institute Co.,Ltd.,Wuhan,Hubei 430056,China;CCCC Second Highway Engineering Bureau Co.,Ltd.,Xi'an,Shaanxi 710054,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2023年第6期1466-1481,共16页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金青年基金项目(52104076)
重庆市研究生科研创新项目(CYB20031)。
关键词
岩石力学
岩质地层
牛腿抗浮结构
室内剪切试验
剪切力学特性
破坏特征
rock mechanics
rock strata
ox leg anti-floating structure
laboratory shear test
shear properties
failure characteristics
