Chen Aikun, Zhai Cheng, Yu Xu, Zheng Yangfeng, Cong Yuzhou, Wu Jianguo
School of Safety Engineering and Research Center for Coal Mine Gas Control, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China.
Key Laboratory of Coal Methane and Fire Control, Ministry of Education, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China.
ACS Omega. 2024 Apr 2;9(15):17076-17088. doi: 10.1021/acsomega.3c08786. eCollection 2024 Apr 16.
Strong-weak coupling outburst prevention technology can reduce the hazard of coal and gas outburst in mines based on hydraulic punching and grouting reinforcement. In this study, the mechanism of outburst hazards in the strong-weak coupling structure under mining disturbance was explored, and then cyclic loading and unloading experiments were performed on samples with different strong-weak height ratios (HRs) using the noncontact full-field strain testing (DIC) system and the acoustic emission (AE) system. The results show that the failure strength of the sample gradually increases with the increase in HR. The residual strain of the strong and weak structures undergoes three stages, i.e., the decelerated deformation, the constant-velocity deformation, and the accelerated deformation. Deformation mainly occurs in the weak structure and starts at the strong-weak interface. The AE signals present strong regional distribution characteristics and the Felicity effect, and the damage is concentrated near 70% of each stage in the cyclic loading process. As the HR rises, the weak structure transitions from brittle damage to ductile damage and from shear damage to tensile damage. In addition, due to the difference in Poisson effects of strong and weak structures, the strong structure transitions from a unidirectional stress state to a triaxial tensile-compressive stress state. When the HR increases to 85:15, the strong structure undergoes tensile damage.
基于水力冲孔和注浆加固的强-弱耦合防突技术能够降低煤矿煤与瓦斯突出灾害。本研究探究了采动扰动下强-弱耦合结构中的突出灾害机理，然后利用非接触全场应变测试（DIC）系统和声发射（AE）系统对不同强-弱高度比（HR）的试样进行了循环加卸载试验。结果表明，试样的破坏强度随HR的增加而逐渐增大。强、弱结构的残余应变经历减速变形、等速变形和加速变形三个阶段。变形主要发生在弱结构中，且始于强-弱界面处。AE信号呈现出较强的区域分布特征和费利西蒂效应，损伤集中在循环加载过程中各阶段的70%左右。随着HR的增大，弱结构从脆性破坏转变为韧性破坏，从剪切破坏转变为拉伸破坏。此外，由于强、弱结构泊松效应的差异，强结构从单向应力状态转变为三轴拉压应力状态。当HR增大到85:15时，强结构发生拉伸破坏。
