不同应力状态下北山花岗岩岩爆倾向性研究

发布时间：2018-01-07 19:23

本文关键词：不同应力状态下北山花岗岩岩爆倾向性研究　出处：《工程科学与技术》2017年06期 　论文类型：期刊论文

【摘要】：为研究不同应力状态下北山花岗岩岩爆倾向性,对北山花岗岩试件进行不同围压下的三轴试验,通过轴向压力和横向变形协调控制加载,获得不同围压下岩石全应力应变曲线,研究岩石破坏前能量聚集及破坏后能量释放特征。结果表明:破坏时弹性能、总能量随着围压增加而增大,且破坏后的总能量变化量及弹性能释放量也随着围压增加而增大。分析岩石储能系数和能量释放指数对岩石破坏的影响,发现岩石储能系数和能量释放指数随围压增加而增大;综合能量储存系数和能量释放指数建立新的岩爆倾向性评价指标,该指标不仅表述了岩石破坏前后各能量的综合变化特征,且能研究不同应力状态下岩石岩爆倾向性;使用该指标研究不同应力状态对北山花岗岩的岩爆倾向性,结果表明:北山花岗岩具有较强的岩爆倾向性,且随着围压增大,岩爆倾向性增加;当围压低于10 MPa时,围压对北山花岗岩岩爆倾向性影响较小,当围压超过10 MPa时,围压对岩爆倾向性的影响突然增加,但随着围压进一步增加,其对岩爆倾向性影响逐渐减弱。
[Abstract]:In order to study the rockburst tendency of Beishan granite under different stress states, the specimens were subjected to triaxial tests under different confining pressures, and the loading was controlled by coordinated axial pressure and lateral deformation. The total stress-strain curves of rock under different confining pressures are obtained and the characteristics of energy accumulation and energy release after failure are studied. The results show that the elastic energy and total energy increase with the increase of confining pressure. The total energy change and elastic energy release also increase with the increase of confining pressure. The influence of rock energy storage coefficient and energy release index on rock failure is analyzed. It is found that the energy storage coefficient and energy release index increase with the increase of confining pressure. A new evaluation index of rock burst tendency is established by synthesizing energy storage coefficient and energy release index, which not only describes the comprehensive variation characteristics of energy before and after rock failure. And the tendency of rock burst under different stress states can be studied. This index is used to study the rockburst tendency of Beishan granite under different stress states. The results show that the rockburst tendency of Beishan granite is strong and the tendency of rock burst increases with the increase of confining pressure. When the confining pressure is lower than 10 MPa, the confining pressure has little effect on the rockburst tendency of Beishan granite, and when the confining pressure exceeds 10 MPa, the influence of confining pressure on the rockburst tendency increases suddenly. However, with the further increase of confining pressure, its influence on rockburst tendency gradually weakened.
【作者单位】：中国矿业大学(北京)力学与建筑工程学院;四川大学水利水电学院;
【基金】：国家国防科技工业局项目资助(高放废物地质处置地下实验室安全技术评价研究) 国家自然科学基金资助项目(51674266)
【分类号】：TU45
【正文快照】： 岩爆是深埋高地应力工程中经常遇到的工程灾害,一旦发生岩爆轻则影响工程顺利进展,重则造成人员伤亡。岩爆倾向性、预测预报及防治技术是研究岩爆必不可少的环节,岩爆倾向性是根据岩石物理力学性质确定工程岩体发生岩爆的可能性,而岩石基本性质是岩爆能否发生的内因,因此岩爆

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