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金属矿山 ›› 2016, Vol. 45 ›› Issue (08): 6-11.

• 采矿工程 • 上一篇    下一篇

基于声发射定位的三轴受压帷幕体试样裂隙演化分析

王志国1,2,李跃龙1,2,王梅1,2,李柱营1,2   

  1. 1.华北理工大学矿业工程学院,河北 唐山 063009;2.河北省矿业开发与安全工程实验室,河北 唐山 063009
  • 出版日期:2016-08-15 发布日期:2016-08-31
  • 基金资助:

    * 河北省自然科学基金项目(编号:E2015209260),唐山市科技计划项目(编号:13130239z)。

Analysis on the Fracture Evolution of the Triaxial Compression Curtain Body Based on Acoustic Emission Location

Wang Zhiguo1,2,Li Yuelong1,2,Wang Mei1,2,Li Zhuying1,2   

  1. 1.College of Mining Engineering,North China University of Science and Technology,Tangshan 063009,China;2.Development and Safety Key Lab of Hebei Province,Tangshan 063009,China
  • Online:2016-08-15 Published:2016-08-31

摘要: 利用TAW-3000电液伺服岩石三轴试验机和PCI-II声发射监测系统对以研山铁矿东帮卵石制作的帷幕体试块进行不同围压三轴压缩条件下的声发射(AE)测试,结合声发射空间定位、AE事件能率对不同应力阶段帷幕体裂隙空间演化规律进行了分析,并对分形维数的变化规律进行了研究。试验结果表明:围压越大,帷幕体试块的抗压强度越高,到达峰值荷载所用时间越多,对应的时间-应力曲线的曲线上升段越长、曲率越小,帷幕体塑性特征越明显,累计AE定位点数越多。分形维数变化基本特征为升维、降维、再升维模式。AE事件能率和定位点数骤然增多以及二次升维标志破坏前兆。同样的应力状态下帷幕体内卵石和砂浆的结合面先起裂,其次是砂和水泥浆的结合面开裂,最后裂缝进入硬化水泥浆。

关键词: 声发射, AE事件能率, 帷幕体, 空间定位, 裂隙演化, 分形维数

Abstract: The acoustic emission (AE) testing of curtain body samples,which are made of gravels taken from the east slope of Yanshan iron ore,was carried out under different confining pressure with TAW-3000 electro-hydraulic triaxial rock mechanics testing machine and PCI-Ⅱ acoustic emission monitoring system.The law of spatial evolution of fractures in curtain body sample is analyzed according to the AE location and AE event energy in different stress stage,and the change rule of fractal dimension was studied.The experimental results indicates that the greater the confining pressure,the greater the compressive strength and the longer the time for reaching the peak load,the longer the curve segment and the smaller the curvature of corresponding time-stress curve,the more obvious the plastic characteristic of curtain body sample,and the more the number of AE location points is.The basic characteristics of the fractal dimension change keep the model of ascending,descending and ascending.The sharp increase of AE events energy and AE location points,and the second increase of fractal dimension can be the prediction of rupture.Under the same stress state,the interface between gravel and mortar in the curtain body sample will rupture firstly,secondly the cracking of interface of sand and cement.Finally,the crack extends into the hardening cement slurry.

Key words: Acoustic emission, AE events energy, Curtain body, Spatial location, Fracture evolution, Fractal dimension