红庆河煤矿弱胶结砂岩单轴加载条件下声发射特征研究

摘要

By means of investigation on acoustic characteristics during the failure process of weakly consolidated sand-stone under uniaxial compression in Hongqinghe coal mine,and according to the mechanical parameters and acoustic emission signal collected from the tests,the curves of stress-strain,stress-time-cumulative count rate,stress-time-absolute energy rate, and the stress-strain-the cumulative count rate,stress-time-absolute energy rate before and after the peak value are drawn. Ac-cording to the stress-strain curves,the rock failure is divided into two types:one is the traditional four stages of rock failure mode;the other is the five stages of failure modes. The ductility stage with stable stress and increasing strain appears at five-stage failure mode after the strain softens. Compared with the acoustic emission characteristics between the two failure modes, the acoustic emission changes a lot after the peak. Under the same compressive strength,samples with less elastic modulus pro-duce more acoustic emission phenomena,but its absolute energy produced are the same. Cumulative count rate can be used to judge whether the samples are completely destructed.%对红庆河煤矿弱胶结砂岩在单轴加载条件下破坏过程中的声发射特征进行研究,根据试验过程中所采集的力学参数和声发射信号参数,得到了全过程应力-应变、应力-时间-累计计数率、应力-时间-绝对能量率以及峰值前、后的应力-应变-累计计数率、应力-时间-绝对能量率曲线. 据所得应力-应变曲线将该类砂岩破坏分为2种形式:一种为传统4阶段岩石破坏形式,另一种为5阶段破坏形式. 5 阶段破坏模式在应变软化阶段后出现了应力不变,应变继续增大的胶结延性阶段. 对比2种破坏模式的声发射特征,峰值后的声发射现象较峰值前的均有量级的变化,抗压强度相近时,弹性模量小的试样产生更多的声发射现象,但产生的绝对能量属于同一量级. 累计计数率能够作为判断试样是否发生完全破坏的参数.