• 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
扰动诱发高应力岩体开挖卸荷围岩失稳机制
  • Title

    Instability mechanism of high stress rock mass under excavation and unloading induced by disturbance

  • 作者

    赵光明许文松孟祥瑞刘崇岩

  • Author

    ZHAO Guangming1,2 ,XU Wensong1,2 ,MENG Xiangrui1,2 ,LIU Chongyan1,2

  • 单位

    安徽理工大学 深部煤矿采动响应与灾害防控国家重点实验室安徽理工大学 能源与安全学院

  • Organization
    1. Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines,Anhui University of Science and Technology,Huainan  232001, China; 2. School of Energy and Safety Engineering,Anhui University of Science and Technology,Huainan  232001,China
  • 摘要

    地下开挖过程中高应力区域围岩易发生动力破坏,对地下工程施工人员及施工设备构成了重大威胁。采用真三轴卸荷扰动岩石测试系统对砂岩进行单面卸荷扰动试验,研究高应力岩体开挖单面卸荷围岩渐进性破坏规律,分析不同初始应力、不同扰动振幅、不同扰动频率静动组合条件下高应力岩体单面卸荷力学、破坏特征。结果表明:① 单面瞬时卸荷时,轴向应变存在瞬时回弹-压缩流变现象,轴向应力越大,回弹量越小,压缩量越大;② 随着第二主应力的增大,破坏强度呈现一个先升高后降低的一个过程,第二主应力为20 MPa处是破坏强度的转折点;③ 高应力岩体单面卸荷破坏为拉伸-劈裂-剪切复合破坏,第二主应力对卸荷破坏的最终形态呈现着关键因素,在第二主应力为10 MPa时,试样出现拉伸-劈裂-剪切裂纹,随着第二主应力的增加,试样内部剪切现象逐渐消失,出现的劈裂裂纹增加,在第二主应力为20 MPa时,试样内部基本全部处于劈裂破坏;④ 动静组合作用下,静载的大小与岩样的强度是决定破坏的主要因素,同等扰动条件下,当静载为破坏强度的80%时,破坏强度为148.6 MPa,静载为破坏值的90%时,岩样的整体破坏强度为142.4 MPa,静载越大岩体破坏所需的触发能量越小破坏值越低,静载相同时,随着扰动振幅、频率的增加,岩体的破坏强度越低,对高应力岩体开挖卸荷围岩支护理论起到了重要的作用。


  • Abstract

    In the process of underground excavation,the surrounding rock in the high stress area is prone to dynamic damage,which poses a major threat to the underground construction personnel and construction equipment. In this pa- per,the rock testing system of true triaxial unloading disturbance is used to test the single-sided unloading disturbance of sandstone. The progressive failure law of surrounding rock in the single-sided unloading roadway of high stress rock mass excavation is studied. The mechanics and failure characteristics of single-sided unloading of high stress rock mass under the conditions of different initial stresses,different disturbance amplitudes and different disturbance frequencies are analyzed. The results show that ① when the single side is unloaded instantaneously,the axial strain has the phe- nomenon of instantaneous rebound compression rheology. The greater the axial stress,the smaller the rebound and the larger the compression. ② With the growth of the second principal stress,the failure strength first increases and then decreases,and the turning point of the failure strength is at the second principal stress of 20 MPa. ③ The single side unloading failure of high stress rock mass is a composite failure of tension splitting shear failure and the second princi- pal stress is the key factor to the final shape of unloading failure. When the second principal stress is 10 MPa,the ten- sile splitting shear crack appears in the sample. With the increase of the second principal stress,the shear phenomenon disappears and the cleavage crack increases. The cleavage failure of the specimen is almost complete when the second principal stress is 20 MPa. ④ Under the combined action of dynamic and static loads,the size of static load and the strength of rock sample are the main factors to determine the failure. Under the same disturbance condition,the static load is 80% of the failure strength,the failure strength is 148. 6 MPa,and the static load is 90% of the failure value, the overall failure strength of the rock sample is 142. 4 MPa. The larger the static load is,the smaller the trigger energy required for rock failure is. When the static load is the same,the lower the failure strength of rock mass is with the in- crease of disturbance amplitude and frequency. These have played an important role in the theory of surrounding rock support for excavation and unloading of high stress rock mass.

  • 关键词

    单面卸荷扰动动静组合失稳机制

  • KeyWords

    single side unloading;disturbance;static and dynamic combination;instability mechanism

  • 基金项目(Foundation)
    国家重点研发计划资助项目(2017YFC0603003);国家自然科学基金资助项目(51974009,51674008)
  • DOI
  • Citation
    ZHAO Guangming,XU Wensong,MENG Xiangrui,et al. Instability mechanism of high stress rock mass under excava- tion and unloading induced by disturbance[J]. Journal of China Coal Society,2020,45(3):936-948.
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