高温作用后层状复合岩石单轴压缩试验损伤机理研究
Study on damage law of layered composite rock under uniaxial compression test after high temperature
付鹏 1亓宪寅 2王胜伟 1耿殿栋 1柯婷1
作者信息
- 1. 长江大学 城市建设学院,湖北 荆州 434023
- 2. 长江大学 城市建设学院,湖北 荆州 434023;中国科学院武汉岩土力学研究所 岩土力学与工程国家重点实验室,湖北 武汉 430071
- 折叠
摘要
为研究深部环境中高温对层状复合岩石物理特性、变形破坏机制及损伤演化规律的影响,在层状复合岩石经过 30、60、90、120、150、180℃高温后开展单轴压缩试验,同时采用声发射仪器监测岩石的破坏过程;以累计振铃计数为损伤变量,考虑高温引入初始损伤,利用复合等效方法得到层状复合岩石的弹性模量,依据裂纹轴向应变、累计振铃计数推导得到全过程应力-应变本构模型.结果表明:层状复合岩石经历高温后,在岩石的初始压密阶段,温度越高,岩石的延性越强;层状复合岩石峰值强度与温度呈负相关关系;声发射中的振铃计数与岩石损伤破坏过程中裂纹的萌生、延伸、扩展到贯通都有很好的对应关系;随着温度的升高,层状复合岩石由脆性向弹塑性转化,破坏模式由垂直劈裂破坏过渡为Y型剪切破坏;建立的全过程应力-应变本构模型可以较好地反映层状复合岩石的损伤演化规律,研究成果可为高温环境下的岩体工程研究提供参考.
Abstract
In order to study the effect of high temperature in deep environment on the physical properties,deformation and failure mechanism and damage evolution law of layered composite rocks,uniaxial compression tests were carried out on layered composite rock after high temperature of 30,60,90,120,150,180℃,and the failure process of rock was monitored by acoustic emission instrument.Taking the cumulative ringing count as the damage variable,considering the initial damage introduced by high temperature,the elastic modulus of layered composite rock was obtained by composite equivalent method.The whole-process stress-strain constitutive model was derived according to the axial strain of crack and the cumulative ringing count.The results show that after the layered composite rocks undergoes high temperature,the higher the temperature,the stronger the ductility of the rocks in the initial compaction stage of the rock.The peak strength is negatively correlated with the increase of temperature after high temperature.The ringing count in acoustic emission is well corresponded with the initiation,extension,and coherence of cracks in the process of rock damage and failure.With the increase of temperature,the layered composite rock changes from brittle to elastic-plastic,and the failure mode changes from vertical splitting failure to Y-type shear failure.The established whole-process stress-strain constitutive model can well reflect the damage evolution law of layered composite rock.The research findings can provide reference for rock engineering in high temperature environment.
关键词
层状复合岩石/高温/单轴压缩试验/声发射/本构模型Key words
layered composite rock/high temperature/uniaxial compression test/acoustic emis-sion/constitutive model引用本文复制引用
基金项目
湖北省自然科学基金项目(2020CFB367)
出版年
2024
NETL
NSTL
万方数据