盐岩高温三轴蠕变损伤破裂机制试验研究  

Experimental study on salt rock creep damage rupture mechanism in high temperature triaxial conditions

作　　者：李浩然[1,2] 徐壮 魏群 刘俊凡 卓崔瑶 LI Haoran;XU Zhuang;WEI Qun;LIU Junfan;ZHUO Cuiyao(Collaborative Innovation Center for Performance and Security of Large-scale Infrastructure,Shijiazhuang Tiedao University,Shijiazhuang,Hebei 050043,China;School of Safety Engineering and Emergency Management,Shijiazhuang Tiedao University,Shijiazhuang,Hebei 050043,China;School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang,Hebei 050043,China)

机构地区：[1]石家庄铁道大学大型基础设施性能与安全省部共建协同创新中心,河北石家庄050043 [2]石家庄铁道大学安全工程与应急管理学院,河北石家庄050043 [3]石家庄铁道大学土木工程学院,河北石家庄050043

出　　处：《岩石力学与工程学报》2023年第12期2945-2956,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(U2034207);河北省自然科学基金资助项目(E2021210099);河北省重点研发计划(21374101D)。

摘　　要：为探究温度影响下盐岩的蠕变行为与损伤演化规律,利用岩石高温三轴蠕变试验机与声发射测试系统,研究35℃,50℃,65℃,80℃,95℃和110℃条件下盐岩蠕变变形特征与声发射活动规律,并结合矩张量反演理论解析震源机制和细微观裂纹扩展模式。研究表明:随环境温度升高,盐岩稳态蠕变率呈指数形式增大,110℃条件下的稳态蠕变率是35℃的35倍。减速蠕变过程中,盐岩声发射活动剧烈,撞击计数率高位波动,b值稳定上升;稳态蠕变过程中,盐岩声发射活动呈间歇性迸发,b值缓慢上升且无明显波动;声发射信号峰值频率呈低频、高频两区带状分布。蠕变环境温度升高,声发射信号峰值频率、高频信号比例和声发射b值均增加,高温环境增强了小尺度微破裂事件的萌生和主导地位。震源破裂滑动角可以较好地表征盐岩晶体的蠕变滑移行为,随环境温度升高,盐岩晶体滑移逐渐由水平方向转向竖直方向发展,但破裂方位走向角和倾角受温度影响较小。研究成果对指导超深盐穴储气库安全设计和长寿命运行具有重要意义。In order to explore the creep behavior and damage evolution law of salt rock under the influence of temperature,the high temperature triaxial creep test machine and acoustic emission test system were used to study the creep deformation characteristics and acoustic emission activity of salt rock at 35℃,50℃,65℃,80℃,95℃and 110℃.The moment tensor inversion theory is employed to analyze the focal mechanism and microscopic crack propagation mode.The results reveal that the steady-state creep rate of salt rock increases exponentially with the increase of the ambient temperature.The steady-state creep rate of salt rock at 110℃is 35 times as much as that at 35℃.In the process of deceleration creep,the acoustic emission activity of salt rock is intense,the impact count rate fluctuates at a high level,and the b value rises steadily.In the process of steady creep,the acoustic emission activity of salt rock is intermittent,and the b value rises slowly and has no obvious fluctuation.The peak frequency of the acoustic emission signal is zonally distributed in a low frequency zone and a high frequency zone.The peak frequency,the proportion of high frequency signal,and b value of acoustic emission signal increase with the increase of the creep environment temperature.The initiation and dominance of small-scale micro-fracture events are enhanced by high temperature environment.The creep slip behavior of salt rock crystals can be effectively characterized by the slip angle of source rupture.The crystal slip of salt rock gradually develops from horizontal direction to vertical direction,while the fracture azimuth strike angle and dip angle are minimally affected by the increase of ambient temperature.The obtained results are of great significance to guide the safety design and long-life operation of ultra-deep salt cavern gas storage.

关 键 词：岩石力学 温度效应 稳态蠕变率 峰值频率 B值 矩张量反演 

分 类 号：TU45[建筑科学—岩土工程]