冻融条件下贺兰口岩石损伤声发射特征研究  

Study on Acoustic Emission Characteristics of Helankou Rock Damage under Freezing-thaw Cycles

作　　者：刘葳 杨有贞 刘美汐 马慧 马文国 张刚 LIU Wei;YANG Youzhen;LIU Meixi;MA Hui;MA Wenguo;ZHANG Gang(School of Mathematics and Statistics,Ningxia University,Yinchuan 750021,China;School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,China;Academic Journal Center,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学数学统计学院,宁夏银川750021 [2]宁夏大学土木与水利学院,宁夏银川750021 [3]宁夏大学学术期刊中心,宁夏银川750021

出　　处：《西北工程技术学报》2024年第3期243-251,共9页Ningxia Engineering Technology

基　　金：宁夏自然科学基金项目(2022AAC03106,2021AAC03095);国家自然科学基金项目(11662015,51768059)。

摘　　要：贺兰口岩石是岩画的重要载体,其在自然环境的作用下遭受了严重的损伤。以贺兰口遗址区岩石为研究对象,模拟贺兰口岩石所在遗址区的赋存环境,开展冻融循环试验、三轴压缩和声发射试验,分析应力-应变特性,讨论峰值应力、残余应力和弹性模量的变化规律,探究声发射信号与冻融循环次数、围压之间的关系。结果表明:相同围压时,岩石经历的冻融次数越多强度越小;相同冻融次数时,峰值应力、弹性模量与围压呈正相关。声发射信号变化阶段与应力-应变曲线相一致,经历了初始小幅度增长阶段、稳定增长阶段、剧烈增长阶段和峰后持续阶段。冻融循环对岩石的声发射前3个阶段影响显著,但对峰后持续阶段影响不明显。冻融次数越多,初始小幅度增长阶段和稳定增长阶段的声发射活动越活跃,且剧烈增长阶段达到的峰值越低。岩石声发射计数在破坏前都有快速增大至峰值的现象,因此可利用声发射计数的陡增对岩石破裂失稳进行预测。Helankou rock is an important carrier of petroglyphs,which has suffered from severe weathering due to the natural environment.This study investigates the damage characteristics of Helankou rock by simulating its natural environment through freezing-thaw cycle tests,triaxial compression tests,and acoustic emission tests.The cycles were set to 0,10,20,30,and 40,respectively.The stress-strain curves were obtained,and the variation laws of peak stress,residual stress,and elastic modulus were analyzed.The relationship between acoustic emission signals and the number of freezing-thaw cycles,as well as confining pressure,was explored.The results indicate that the more freezing-thaw cycles the rock undergoes at the same confining pressure,the lower its strength becomes.The peak stress and elastic modulus show a positive correlation with confining pressure under the same number of freezing-thaw cycles.The variation stages of the acoustic emission signal align with the stress-strain curve,going through initial small growth,stable growth,sharp increase,and post-peak persistence.With an increasing number of freezing-thaw cycles,the early acoustic emission activity in the initial small growth and stable growth stages becomes more pronounced,while the peak reached during the sharp increase stage decreases.Before failure,the acoustic emission count rapidly increases to a peak,indicating that this parameter can be used to predict rock failure instability.The research results provide a theoretical basis for the protection of Helankou rock paintings.

关 键 词：冻融循环 声发射 损伤特性 贺兰口岩石 岩画 

分 类 号：TU458[建筑科学—岩土工程]