摘要
外荷作用下的岩石变形破坏过程可以用岩石声发射特征来反映。本文以闪长岩为研究对象,将岩芯沿与岩芯轴线夹角分别为0°、45°、90°方向加工成直径为50 mm、高为100 mm的圆柱状试样,进行了试样的单轴压缩试验和声发射试验,将声发射特征参数(包括振铃计数、事件数、能量)用瞬时参数与累计参数来表征,分析了岩石变形破坏过程中声发射特征参数的变化情况,研究了传感器位置对声发射参数的影响,提出了Kaiser点的确定方法。结果表明,根据振铃计数与声发射事件数,声发射过程可分成声发射活跃期和声发射平静期;声发射活跃期共有三次,每次持续时间均短暂且均伴随着裂隙的产生与扩展,声发射平静期共有两次、分别发生于新生裂隙出现之后和岩石完全破坏之前;能量在岩石完全破坏前一段时间内释放较少,在岩石破坏时释放很多;传感器位于试样上部和下部时声发射特征参数整体变化趋势一致,但位于下部时声发射参数变化更具有明显的三次声发射活跃期和两次声发射平静期; Kaiser点可以结合声发射特征瞬时与累计参数准确确定。研究成果对分析岩石的变形破坏机理具有一定的参考价值。
The deformation and failure process of a rock under external load may be reflected by the acoustic emission features.Taking diorite as an example,the cylindrical specimens with a diameter of 50 mm and a height of 100 mm were made from the field core respectively with the angles of 0,45 and 90 degrees between the specimen and core axes.The laboratory uniaxial compression tests and acoustic emission tests were then performed.The acoustic emission features,including the ring count,event number and energy,were characterized with instantaneous and cumulative parameters.The changes in the acoustic emission parameters during the deformation/failure process of the rock were there after analyzed.The influences of the sensor position on the acoustic emission parameters were also investigated. The determination technique of the Kaiser point was further more proposed.It shows that according to the ringing count and event number,the acoustic emission process of diorite was divided into two stages,or active and quiet ones;the active stage occurred three times,and the duration of each time is much shortduring the generation and expansion of cracks,the quiet stage occurred two times,occurred respectively after the generation of new cracks and before the complete failure of the rock;the energy is less released before the complete failure of the rock and released with a large amount just as the rock failure;the change trend of the acoustic emission parameters was relatively consistent whether the sensors located in the upper or lower positions,whereas the trend of the three active stages and two quite stages was more obvious during the deformation and failure of the rock if the sensor is placed in the lower positions;the Kaiser point may be accurately determined if the combination of the instantaneous and cumulative acoustic emission parameters were used.The results presented here in may provide references for studying the deformation/failure mechanisms of the rock materials.
作者
吴述宽
徐金明
涂齐亮
WU Shukuan;XU Jmming;TU Qiliang(Department of Civil Engineering,Shanghai University,Shanghai 200444,China;Basic Scientific Research Institute of Cultural Heritage Protection,Shanghai University,Shanghai 200444,China;China Railway 17Bureau Group Co.Ltd.,Taiyuan,Shanxi 030006,China)
出处
《中国地质灾害与防治学报》
CSCD
2018年第6期126-134,共9页
The Chinese Journal of Geological Hazard and Control
基金
国家自然科学基金资助项目(41472254)
关键词
岩石力学
闪长岩
单轴压缩
声发射
rock mechanics
diorite
uniaxial compression
acoustic emission
作者简介
第一作者:吴述宽(1993一),男,硕士研究生,主要从事岩土工程的科研工作。E—mail:wshukuan@163.com;通讯作者:徐金明(1963一),男,博士,教授,博士生导师,主要从事工程地质与岩土工程的教学与科研工作。E-mail:xjming@163.com.
