水对粉砂岩渐进破裂过程影响实验研究

发布时间：2018-03-09 17:10

本文选题：水　切入点：粉砂岩　出处：《矿产保护与利用》2017年01期 　论文类型：期刊论文

【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。
[Abstract]:Through the experiments on dry, natural and saturated siltstone under uniaxial compression, Based on acoustic emission (AE) method, damage strength 蟽 _ (cd), the progressive fracture index of rock is determined, and the influence of water on the progressive fracture process of siltstone is studied. The results show that the uniaxial compressive strength and elastic modulus of siltstone decrease with the increase of water content. The relationship between them and water content can be fitted by exponential function. The correlation degree is about 0.8, the residual strength increases with the increase of water content, and the intensity of acoustic emission events decreases with the increase of water content. The number of cumulative AE events decreases and the rock rupture degree is reduced by water during failure, and an important feature of AE activity before failure and instability of siltstone is found: the increasing mode of accumulated AE event number 危 AE conforms to the Exponential function, and the water content increases. The effect of water on the progressive rupture process of siltstone is mainly reflected in the increase of the ratio of damage strength to peak strength (蟽 cd/ 蟽 c) of siltstone after water content, and the increase of stress level in the initiation of unstable crack propagation in siltstone. Water can accelerate the process of siltstone spreading from crack instability to macroscopic instability.
【作者单位】：华北理工大学矿业工程学院;华北理工大学河北省矿业开发与安全技术重点实验室;
【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)
【分类号】：TD315

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