摘要
华北石炭二叠纪聚煤区是中国最重要的煤炭生产基地,区内众多煤矿皆受煤系底部奥陶系灰岩承压水威胁。针对当前煤矿巷道底板承压水突水评价方法存在的局限和不足,探索研究巷道底板承压水突水评价方法。现行评价方法岩梁法的理论计算前提主要包括:底板隔水层简化为两端固支梁;在岩梁弯矩最大处,底板隔水岩层承受的拉应力超过抗拉强度,岩层拉裂破坏;忽略孔隙水压力对岩石破坏的影响,计算隔水层厚度时抗拉强度取底板隔水层的平均值。事故数据及研究分析表明岩梁法计算假设存在不合理之处,与实际工况有较大偏差。基于对常见矩形巷道围岩应力分布特征的分析,结合巷道实际工况,摒弃底板隔水岩层弯拉破坏模式,提出隔水岩层剪切破坏模式,建立巷道底板承压水突水破坏岩柱模型;基于所建立的岩柱模型,利用极限平衡理论,综合考虑孔隙水压力对岩石破坏的影响,推导底板隔水层承受最大水压的计算评价方法。结果表明:最大水压与隔水层厚度、隔水层平均容重、抗剪强度参数、孔隙水压力系数和巷道宽度直接相关,最大水压与隔水层厚度呈指数函数关系。文中所提评价方法的计算结果与实测吻合,证明该方法合理有效。所提方法也能为地下工程其他专业领域类似的承压水突水问题研究提供借鉴。
The Carboniferous-Permian coal-bearing region is the most important coal production base in China,and coal mining is threatened with confined water from the Ordovician limestone aquifer in many coal mines.Aiming at some limitation and deficiency in the current evaluation method about confined water inrush from roadway floor in coal mine,the evaluation method was explored and studied.In the current rock beam method,the main theoretical calculation hypothesis contained:the water-resisting layer was treated as a clamped-clamped beam.The floor waterresisting layer tension failure was caused by tensile stress exceeding the tensile strength of the rock,at the maximum of the beam moment.The influence of pore water pressure on rock damage was neglected,and the thickness of water-resisting layer was calculated using the average tensile strength of the floor strata.Accident data and researches evidenced that there were some unreasonable parts and a big deviation between actual working conditions and calculation conditions,in the main theoretical hypothesis of rock beam method.By analyzing the stress distribution characteristics of the surrounding rock in common rectangle roadway and combining with actual working conditions,the floor strata tension failure model was abandoned and the shear failure model was formulated,then a new rock pillar mechanical model of confined water inrush in rectangle roadway was built.Based on the new rock pillar model,and taking the influence of pore water pressure on rock damage into consideration,a new formula calculating the critical hydraulic pressure that the floor water-resisting layer could withstand was given using limit equilibrium theory.The new formula showed that there was a direct relationship between the critical hydraulic pressure and the thickness of water-resisting layer,average volume-weight,shear strength parameters,pore water pressure parameters and the roadway width,and the critical hydraulic pressure exhibited exponent relation with the thickness of water-resisting layer.Th
出处
《四川大学学报（工程科学版）》
CSCD
北大核心
2017年第3期104-109,共6页
Journal of Sichuan University (Engineering Science Edition)
基金
国家自然科学基金资助项目(51369001)
河南省科技攻关计划项目资助(172102310706)
河南省高等学校重点科研项目资助(16A44001)
关键词
承压水
底板突水
最大水压
隔水层厚度
岩柱法
confined water
floor water inrush
maximum hydraulic pressure
thickness of water resisting layer
rock pillar method
