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
刘葳 1杨有贞 2刘美汐 1马慧 2马文国 2张刚3
作者信息
- 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 土木与水利学院,宁夏 银川 750021;宁夏大学 学术期刊中心,宁夏银川 750021
- 折叠
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.
Abstract
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Key words
freeze-thaw cycle/acoustic emission/damage characteristics/Helankou rock/rock painting引用本文复制引用
基金项目
宁夏自然科学基金项目(2022AAC03106)
宁夏自然科学基金项目(2021AAC03095)
国家自然科学基金项目(11662015)
国家自然科学基金项目(51768059)
出版年
2024
国家科技期刊平台
NSTL
万方数据