水对粉砂岩渐进破裂过程影响实验研究  

Experimental Study on Effect of Water on Progressive Failure Process of Siltstone

作　　者：孙林[1,2] 梁鹏[1,2] 张艳博[1,2] 田宝柱[1,2] 

机构地区：[1]华北理工大学矿业工程学院,河北唐山063009 [2]华北理工大学河北省矿业开发与安全技术重点实验室,河北唐山063009

出　　处：《矿产保护与利用》2017年第1期22-28,共7页Conservation and Utilization of Mineral Resources

基　　金：国家自然科学基金项目(51374088;51574102);河北省高等学校科学技术研究项目(QN2016124;QN2016125);华北理工大学科学研究基金项目(Z201315;Z201501)

摘　　要：通过对干燥、自然和饱水粉砂岩进行单轴压缩声发射实验,基于声发射方法确定岩石渐进破裂指标—损伤强度σcd,研究水对粉砂岩渐进破裂过程的影响规律。研究结果表明:粉砂岩的单轴抗压强度和弹性模量随含水率的增加而减小,两者与含水率的关系可以用指数函数进行拟合,相关度在0.8左右,残余强度随含水率的增加而增大;随着含水率的增加,粉砂岩破裂前声发射事件率密集的程度降低,破坏时的累计声发射事件数减少,水降低了岩石的破裂程度;粉砂岩破裂失稳前声发射活动的一个重要特点:累计声发射事件数ΣAE的增长模式符合Exponential函数,含水率增加,其增长的速率降低;水对粉砂岩渐进破裂过程的影响主要表现在含水后粉砂岩损伤强度与峰值强度的比值(σcd/σc)增加,粉砂岩裂纹开始不稳定扩展的应力水平提高,水可以加速粉砂岩从裂纹不稳定扩展到宏观失稳的过程。The uniaxial compression acoustic emission experiment of the drying,natural and saturated sandstone was conducted. Applying acoustic emission to determine the rock progressive failure index damage strength σcd,then the influence of water on the progressive rupture process of siltstone was studied. The results showed that compressive strength and elastic modulus of siltstone decrease with an increase of moisture content,the relationship with the water content could be fitted with an exponential function,of which the correlation is about 0. 8. The residual strength increases with the increase of moisture content. As the moisture content increases,the intensity of the acoustic emission event rate reduces before siltstone rupture,and the destruction of the cumulative AE event number decreases. Therefore,water reduces the rupture degree of rock. An important feature of AE activity before siltstone rupture is that the cumulative number of acoustic emission events（ ΣAE） conform to an exponential growth model,and the growth rate of it decreases with the increase of moisture content. The effect of water on the siltstone progressive failure process is mainly manifested in increasing the ratio of damage intensity and peak intensity（ σcd/ σc）,and the stress level of crack unstable extension,which indicates water can accelerate the process from the unstable crack extension to the macroscopic instability.

关 键 词：水 粉砂岩 声发射 渐进破裂 损伤强度 

分 类 号：TD851[矿业工程—金属矿开采]