摘要
为了探讨含水率对红砂岩特征应力及声发射响应特征的影响,利用RMT-150C岩石力学压力试验机和PCI-II AE win型声发射系统开展了不同含水率条件下红砂岩试件单轴压缩试验。对水侵蚀作用下红砂岩的物理力学参数及特征应力演化机制进行了分析,探究在不同含水率条件下声发射(宽、窄频带)时间序列模式的演化规律,同时基于累计声发射事件数与统计力学理论构建了红砂岩的损伤演化模型。试验结果表明:(1)P波波速随着含水率增加呈现先减小后增加的变化趋势,当含水饱和度达到临界值时,P波波速会降到最低值;(2)窄频带接收传感器接收的声发射信号与红砂岩内部颗粒间的摩擦作用息息相关,而宽频带接收传感器接收的声发射信号与红砂岩内部裂纹演化存在着内在联系;(3)水对声发射事件率(宽频带)在裂纹非稳定扩展阶段影响相对较为显著,对特征应力与强度的比值影响甚微,但对各阶段应变百分比作用效果相对较为明显,随着含水率的增加,红砂岩试件的失效模式由脆性破坏逐渐向延展性破坏转变;(4)随着含水率的增加,声发射事件率(窄频带)活跃期呈现后移的变化趋势,干燥、自然与饱和状态下岩石试件声发射模式分别为主震型、前震–主震–后震型和群震型;(5)基于声发射累计事件数(宽、窄频带)与统计力学理论构建的损伤演化模型可将不同含水率条件下红砂岩试件的损伤过程分为4个阶段:初始损伤阶段、损伤稳定发展阶段、损伤加速发展阶段及损伤破坏阶段。
In order to investigate the response law of moisture content to the characteristic stress and acoustic emission characteristics of red sandstone,the uniaxial compression tests of red sandstone under different moisture content conditions were conducted using RMT-150 C rock mechanical pressure testing machine and PCI-ⅡAE win acoustic emission system.The physical and mechanical parameters and characteristic stress evolution mechanism of red sandstone under water erosion are analyzed,and the evolution law of acoustic emission(wide and narrow-band)time series mode under different moisture content conditions is also investigated.At the same time,the damage evolution model of red sandstone is constructed based on cumulative acoustic emission event number and statistical mechanics theory.The results show that:1)The P-wave velocity decreases first and then increases with the increase of moisture content.When the water saturation reaches a critical value,the P-wave velocity will drop to the lowest value.2)The acoustic emission signal received by the narrow-band receiving sensor is closely related to the friction between the particles in the red sandstone,and the acoustic emission signal received by the wide-band receiving sensor is intrinsically related to the evolution of the internal cracks in the red sandstone.3)The moisture content has a significant effect on the acoustic emission event rate(wide-band)at the stage of unstable crack propagation,and has a minor effect on the ratio of characteristic stress to peak strength,but it has a relatively obvious effect on the strain percentage at each stage.With the increase of moisture content,the failure mode of red sandstone specimens gradually changes from brittle failure to ductile failure.4)As the moisture content increases,a"backward"change trend can be observed for the active period of acoustic emission event rate(narrow-band),and the acoustic emission modes of dry,natural,and saturated rock samples correspond to mass shocks,pre-main-later shocks and swarm shocks type,respectively.(5)According to the damage model based on the cumulative number of acoustic emission events(wide and narrow-band),the damage process of red sandstone can be divided into four stages:initial damage stage,stable damage development stage,accelerated damage development stage and damage destruction stage.
作者
赵奎
冉珊瑚
曾鹏
杨道学
腾天野
ZHAO Kui;RAN Shan-hu;ZENG Peng;YANG Dao-xue;TENG Tian-ye(School of Resources and Environmental Engineering,Jiangxi University of Science and Technology,Ganzhou,Jiangxi 341000,China;Jiangxi Provincial Key Laboratory of Mining Engineering,Jiangxi University of Science and Technology,Ganzhou,Jiangxi 341000,China;Shenhua Nortel Shengli Energy Co.,Ltd.,Xilinhot,Inner Mongolia 026000,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2021年第4期899-908,共10页
Rock and Soil Mechanics
基金
国家重点研发计划(No.2017YFC0804601)
国家自然科学基金(No.51664018)
江西理工大学优秀博士论文培育项目(No.3105500025)。
关键词
含水率
特征应力
响应频带
声发射模式
损伤系数
moisture content
characteristic stress
response frequency band
acoustic emission mode
damage coefficient
作者简介
第一作者:赵奎,男,1969年生,博士,教授,博士生导师,主要从事岩石力学与工程方面的研究工作,E-mail:296931654@qq.com;通讯作者:杨道学,男,1990年生,博士研究生,主要从事岩石力学与工程方面的研究工作。E-mail:daoxuey@126.com。
