弱胶结砂质泥岩注水软化与渗流特性试验研究——以神东矿区为例  

Experimental study on water-softening and seepage characteristics of weakly cemented sandy mudstone:Taking Shendong Coal Mining Area as an example

作　　者：张凯 郭俊廷 滕腾 ZHANG Kai;GUO Junting;TENG Teng(State Key Laboratory of Water Resource Protection and Utilization in Coal Mining,Beijing102209,China;Science and Technology Development Department,China Energy Investment Corporation,Beijing100011,China;National Institute of Clean and Low Carbon Energy,Beijing102209,China;School of Energy and Mining Engineering,China University of Mining and Technology-Beijing,Beijing100083,China)

机构地区：[1]煤炭开采水资源保护与利用国家重点实验室,北京102209 [2]国家能源投资集团有限责任公司科技部,北京100011 [3]北京低碳清洁能源研究院,北京102209 [4]中国矿业大学(北京)能源与矿业学院,北京100083

出　　处：《煤炭科学技术》2022年第2期195-201,共7页Coal Science and Technology

基　　金：国家自然科学基金资助项目(52004285)。

摘　　要：神东矿区基岩弱胶结特性显著,岩体遇水后的软化和渗流特性是煤炭地下开采顶板注水软化治理、突透水事故防治、煤矿地下水库建设等工程领域的共性和基础性难题。针对神东布尔台矿弱胶结砂质泥岩,系统开展了岩石吸水、单三轴压缩、巴西劈裂和渗流等试验,获得了自然和饱水状态下的砂质泥岩力学参数与拉压变形、渗流曲线及其特征。研究结果表明,神东矿区弱胶结砂质泥岩的水岩固体软化效应、流体传质效应显著,在相关的地下工程中必须充分考虑,具体如下:①弱胶结砂质泥岩吸注水后塑性明显增强,软化效果显著,岩石抗压强度减小29%~57%,围压越小,软化效果越明显;不同围压下弹性模量均减小25%~30%,随着围压的增大弹性模量的减小量有增大趋势;在低围压下,泊松比增大效果显著,在高围压下,泊松比变化不大;岩石三轴压缩破坏峰后跌落应变增大12%,且随围压的增大而减小;单轴抗拉强度下降66%;②试验所用神东矿区布尔台矿顶板砂质泥岩的抗拉强度与抗压强度的比值约为1/10,且岩石吸水后该比值基本保持不变;③弱胶结砂质泥岩的水渗过程易导致裂缝通道局部的崩解,渗透率随注水压力梯度的增大而增大,随围压的增大而减小,渗透率随裂缝通道的崩解而瞬时减小。研究结果为揭示神东矿区弱胶结砂质泥岩水岩耦合力学特性和开展相关工程实践提供了一定的理论依据。The weak cementation characteristics of bedrock in Shendong mining area are obvious, and the softening and seepage characteristics of rock mass after encountering water are common and basic problems in engineering fields such as softening treatment of roof water injection in underground coal mining, prevention and control of water inrush accidents, and construction of coal mine underground reservoirs. Aiming at the weakly cemented sandy mudstone in Shendong Buertai Mine, the paper systematically carried out rock water absorption, single triaxial compression, Brazilian splitting and seepage experiments, and the mechanical parameters and tensile-compression deformation of sandy mudstone as well as the seepage curves and their characteristics in natural and water-saturated conditions were obtained. The research results show that the water-rock solid softening effect and fluid mass transfer effect of weakly cemented sandy mudstone in Shendong mining area are significant, which must be fully considered in related underground engineering, as follows:(1) The plasticity of weakly cemented sandy mudstone after water injection Significantly enhanced, the softening effect is significant, and the compressive strength of rock decreases by 29%-57%, and the smaller the confining pressure, the more obvious the softening effect;the elastic modulus decreases by 25%-30% under different confining pressures. Under low confining pressures, the Poisson’ s ratio increases significantly, and under high confining pressure, Poisson’ s ratio does not change much. The post-peak dropping strain increases by 12%, and decreases with the increasing confining pressure. The uni-axial tensile strength decreases by 66%.(2) For the used sandy mudstone samples from Shendong area, the tensile strength is 1/10 of the compressive strength, and the ratio remains basically unchanged after the rock absorbs water.(3) The water seepage process of weakly cemented sandy mudstone easily leads to local collapse of fracture channels. The permeability of weakly

关 键 词：岩石力学 砂质泥岩 水理效应 渗流特性 弱胶结 注水软化 

分 类 号：TD745[矿业工程—矿井通风与安全]