摘要
为解决西部弱胶结软岩巷道支护难题,在内蒙古鲁新煤矿对典型弱胶结泥岩取样,并对其进行不同状态(天然状态、饱和状态和烘干状态)和不同围压水平的室内三轴压缩试验,分析其强度特征和基本力学指标与围压的变化关系。试验数据表明:1自然状态下弱胶结泥岩峰值强度和残余强度非常低,随着围压的增加,泥岩的峰值强度和残余强度均有较大提高,且峰值强度与围压呈对数变化关系;2泥岩对水非常敏感,随着含水率的增加峰值强度和残余强度均降低,峰值强度降低幅度更明显;3通过引入三轴软化系数进行分析,结果表明泥岩的软化系数随围压增加而下降,泥岩3种状态下的弹性模量与围压增加呈线性增大变化。最后通过泥岩三轴压缩四阶段应力-应变曲线的拟合分析,建立了泥岩三轴压缩全应力-应变关系。
In order to solve the roadway support problem of weakly cemented soft rock in west China,we collected typical weakly cemented mudstone samples in Luxin coal mine in Inner Mongolia,and conducted indoor triaxial compression test on the soft rock at different states（ natural state,saturation state,dry state） under different stress levels. We analyzed the relations of strength characteristics,fundamental mechanical indexes vs. confining pressure.The results are as follows： firstly,the peak strength and residual strength of weakly cemented mudstone are very low under natural condition. With the increasing confining pressure,the peak strength and residual strength of mudstone both have a larger increase,and the relationship between peak strength and confining pressure is logarithmic. Secondly,as mudstone is very sensitive to water,peak strength and residual strength decreases with the increasing moisture content,while peak strength decreases more significantly. Thirdly,softening coefficient decreases with the increasing confining pressure,and the elastic moduli of mudstone under three different states increase linearly with the increasing confining pressure. Lastly,we established the triaxial compression stress-strain relationship by analyzing the four-stage triaxial compression stress-strain fitting curve of mudstone.
出处
《长江科学院院报》
CSCD
北大核心
2016年第8期86-90,95,共6页
Journal of Changjiang River Scientific Research Institute
基金
国家自然科学基金项目(51404193)
中国博士后基金面上项目(2015M572581)
陕西省自然科学基金青年人才项目(S2015YFJQ1194)
关键词
弱胶结泥岩
三轴压缩试验
应力-应变曲线
变形特征
峰值强度
残余强度
weakly cemented mudstone
triaxial compression test
stress-strain curve
deformation characteristic
peak strength
residual strength
