• 论文
主办单位:煤炭科学研究总院有限公司、中国煤炭学会学术期刊工作委员会
裂隙红砂岩冻胀力特性试验研究
  • Title

    Experimental study on frost heaving pressure properties in fractured red sandstone

  • 作者

    单仁亮白瑶孙鹏飞吴永鑫隋顺猛原鸿鹄

  • Author

    SHAN Renliang,BAI Yao,SUN Pengfei,WU Yongxin,SUI Shunmeng,YUAN Honghu

  • 单位

    中国矿业大学(北京)力学与建筑工程学院

  • Organization
    School of Mechanics and Civil Engineering,China University of Mining and Technology (Beijing),Beijing  100083,China
  • 摘要

    裂隙岩体冻胀现象在富水岩层冻结工程中普遍存在,冻胀力易使得岩体裂隙尖端应力集中而产生新的微裂纹,微裂纹扩展贯通导致岩体发生不同程度破坏。为揭示裂隙岩体冻融损伤演化机制,探究以冻胀力驱动下的岩体裂隙扩展规律,利用超薄型电阻式压力传感器、温度传感器、低温恒温箱组成的冻胀力测试系统对不同冻结速率、不同裂隙尺寸、倾角以及不同边界条件下红砂岩贯通裂隙中的冻胀力进行测试,分析了贯通裂隙中冻胀力演化规律、冻胀劣化机制以及冻胀破坏模式。结果表明:含贯通裂隙试样典型冻胀力演化过程分为初始冻结阶段、迅速上升阶段、卸荷阶段、维持阶段、消散阶段;冻胀作用使得贯通裂隙端部附近出现明显裂纹扩展现象,试样整体呈竖向张拉破坏;贯通裂隙最大冻胀力随隙宽呈单指数函数增长、与温度成线性正相关;冻结过程中,试样边界条件对裂隙冻胀力影响显著,刚性约束边界条件下最大冻胀力达到1.27 MPa,融化过程中,不同边界条件对应不同冻胀力跌落现象;低温条件下贯通裂隙红砂岩冻胀力变化特征与冻胀过程中声发射能量变化规律一致,充分验证了冻胀力对贯通裂隙岩体的损伤劣化作用。研究成果可为裂隙岩体冻胀力理论计算与数值分析、冻融损伤机制、冰-岩耦合特性以及煤矿立井冻结壁设计等提供参考。

  • Abstract
    Frost heave phenomenon of fractured rock mass is widespread in the freezing engineering of water-rich rock strata. Frost heave force tends to cause stress concentration at the crack tip of rock mass to produce new micro-cracks. The propagation and penetration of micro-cracks lead to different degrees of damage of rock mass. In order to reveal the evolution mechanism of freeze-thaw damage in fractured rock mass and explore the law of fracture propagation in rock mass driven by frost heave force the frost heaving force in the connected crack of red sandstone is tested by a frost heave force testing system which consists of ultra-thin resistance pressure sensor,temperature sensor and low tempera- ture and constant temperature box under different freezing rates,fracture sizes,dip angles and boundary conditions. Then the evolution law of frost heaving pressure,the mechanism of frost heaving deterioration and the failure mode of frost heaving are analyzed. The results show that the evolution process of typical frost heaving pressure of fractured red sandstone includes initial freezing stage, rapid freezing stage, unloading stage, maintenance stage and disappearing stage. The frost heaving effect causes obvious crack propagation behavior near the tip of crack,and the samples are vertical tension destruction. The maximum frost heaving pressure increases single exponentially with the width of gap and increases linearly with temperature. During the freezing process,the boundary condition of the sample has a signifi- cant influence on the frost heaving pressure of fracture,the maximum frost heaving force is 1. 27 MPa under rigid con- fined boundary conditions. During the melting process, different boundary conditions correspond to different falling phenomena of frost heaving pressure. The characteristics of frost heaving pressure in red sandstone with penetrating fracture under low temperature is consistent with the law of AE energy change during the process of frost heave,and the damage and deterioration effect of frost heaving force on the fractured rock mass is fully verified. The research re- sults can provide a reference for the theoretical calculation and numerical analysis of frost heaving pressure in fractured rock mass,the mechanism of freezing and thawing damage,the characteristics of ice-rock coupled and the design of the frozen wall of the coal mine.
  • 关键词

    冻结壁红砂岩裂隙产状冻胀力冻胀扩展

  • KeyWords

    frozen wall;red sandstone;fracture morphology;frost heaving pressure;frost heaving propagation

  • 基金项目(Foundation)
    国家自然科学基金资助项目(41572270)
  • DOI
  • Citation
    SHAN Renliang,BAI Yao,SUN Pengfei,et al. Experimental study on frost heaving pressure properties in fractured red sandstone [J]. Journal of China Coal Society,2019,44(6):1742-1752.
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