薛维培,申磊,姚直书,等. 流固耦合状态下煤矿井壁破损透水机理研究[J]. 煤田地质与勘探,2023,51(10):86−93. DOI: 10.12363/issn.1001-1986.22.10.0759
引用本文: 薛维培,申磊,姚直书,等. 流固耦合状态下煤矿井壁破损透水机理研究[J]. 煤田地质与勘探,2023,51(10):86−93. DOI: 10.12363/issn.1001-1986.22.10.0759
XUE Weipei,SHEN Lei,YAO Zhishu,et al. Water inrush mechanism of coal mine shaft fracture under fluid-solid coupling[J]. Coal Geology & Exploration,2023,51(10):86−93. DOI: 10.12363/issn.1001-1986.22.10.0759
Citation: XUE Weipei,SHEN Lei,YAO Zhishu,et al. Water inrush mechanism of coal mine shaft fracture under fluid-solid coupling[J]. Coal Geology & Exploration,2023,51(10):86−93. DOI: 10.12363/issn.1001-1986.22.10.0759

流固耦合状态下煤矿井壁破损透水机理研究

Water inrush mechanism of coal mine shaft fracture under fluid-solid coupling

  • 摘要: 煤矿井壁破损透水事件时有发生,给地下空间利用和矿产资源开采构成重大威胁。为了弄清井壁破损过程承压地下水存在的影响以及透水通道形成机制,采用相似理论设计模型试验并结合流固耦合数值模拟技术开展研究。结果表明,井壁与压力水直接接触不利于其承载变形能力的发展,具体体现在破坏时屈服点位置提前出现,峰值强度及峰值应变降低,宏观裂纹分布更广,这是由压力水渗入井壁混凝土时诱发的渗流场应力场相互耦合作用引起的。对照模型试验结果开展数值仿真分析,获得一套适用于流固耦合状态下井壁破损数值计算参数。基于此开展0.05、0.10、0.20、0.40 MPa孔隙水压影响下井壁破损透水全过程细观数值分析,发现孔隙水压增大使井壁承受的临界侧向荷载依次降低5.88%、17.65%、23.53%,屈服强度附近试件内部裂纹发展明显加速,裂纹不断扩展、贯通,最终形成沟通井壁内外侧壁的透水通道。0.40 MPa孔隙水压下透水通道率先出现,相对于其他3种孔隙水压提前了2.67、2.53、1.67倍计算步,说明孔隙水压越大裂纹扩展速率越快,裂纹扩展路径先径向后环向。声发射监测表明井壁破损透水前夕,事件数量先逐步增大再持续保持高位,破损后应力得到释放,声发射事件频率及数量骤降,该信号特征可作为现场井壁破损透水监测依据,为井壁突水预防和治理提供依据。

     

    Abstract: The occurrence of coal mine shaft fractures and water inrush accidents is alarmingly frequent, endangering the lives of underground personnel and compromising mine safety. To comprehend the influence of confined groundwater in the process of shaft fracture and the formation mechanism of water inrush channels, a model test was devised using similarity theory and coupled fluid-solid numerical simulation technology. The findings reveal that direct contact between the shaft lining and pressurized water hinders the development of load-bearing and deformation capacities. This is specifically evidenced by the premature appearance of the yield point, a reduction in peak strength and strain, and a broader distribution of macro cracks. These effects result from the coupling interaction between the seepage field and stress field induced by the penetration of pressurized water into the concrete lining of the shaft. Numerical simulation analysis based on the model test results yields a set of parameters for calculating shaft fractures under fluid-solid coupling conditions. Subsequently, a meso-numerical analysis of shaft fracture and water permeability processes is conducted under different pore water pressures: 0.05, 0.10, 0.20, and 0.40 MPa. It is observed that an increase in pore water pressure leads to a reduction of 5.88%, 17.65%, and 23.53% in the critical lateral load on the shaft, respectively. Internal crack development near the yield strength of the specimen is notably accelerated, with cracks expanding continuously and eventually forming permeable channels that connect the interior and exterior of the shaft lining. The water inrush channel first emerges under a pore water pressure of 0.40 MPa, which is 2.67, 2.53, and 1.67 times earlier than the other three pore water pressures. This indicates that higher pore water pressure corresponds to a faster crack growth rate, with the crack initially propagating radially before transitioning to a circumferential path. Acoustic emission monitoring demonstrates a gradual increase in the number of events leading up to the occurrence of shaft fracture, followed by a sustained high level of activity. Once the water inrush channel is formed, stress is relieved, resulting in a sharp drop in the frequency and number of acoustic emission events. This characteristic can serve as a basis for on-site monitoring of water inrush from shaft fractures, which providing evidence for the prevention and control of water inrush as well.

     

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