大刚度高强度二次支护巷道控制机理与应用

通过理论研究和现场多种支护方式的对比试验,建立了大刚度高强度二次支护巷道黏弹、黏塑性力学模型;进行了软岩巷道一次锚网喷支护、二次大刚度高强度支护围岩稳定控制的理论计算、分析与应用。根据理论计算结果,分析了二次支护前后围岩体应力状态的转化结果,得出了二次支护最大工作阻力值的黏弹、黏塑性理论解析解;并确定了第二次大刚度高强度支护的合理参数,选择了安全可靠的支护方法,实现了巷道的长期稳定。二次支护巷道围岩稳定控制的机理为:一次支护让压围岩体受力达到较低变形速率下的力学平衡,充分发挥围岩的承载作用;二次大刚度高强度支护避免围岩体处于高应力状态下及再次应变软化与蠕变劣化导致的承载力降低、状态恶化,减少巷道岩体偏应力,促进围岩应力向长期强度和巷道稳定的流变停止状态转化。

Control mechanism and application of doubly supported roadways with large rigidity and high strength

Through theoretical researches and contrast testes on various support modes in mines,a viscoelastic,viscoplastic mechanical model for doubly supported roadway with large rigidity and high strength was established.Theoretical calculation,analysis,application of stability control of surrounding rock for the soft rock roadway supported by bolting and shotcreting the first support and the second support with large rigidity and high strength.According to the results of the theotetical calculation,the convertion of the stress state of surrounding rock before and after the setting of second support were analyzed;the theoretical viscoelastic and viscoplastic solution on the maximum operation resistance of the second support was obtained;the parameters of the second support with large rigidity and high strength were determined;the safe and reliable supporting method was selected;the long-term stability of the roadway was realized successfully.The mechanism of stability control of rock surrounding the roadmay with double supports was summarized as follows.With the pressure released by the first support,the support capacity of the rock mass was fully used,and its stress state would be in agreement with the low deformation rate.The high stress state and reduction of the bearing capacity of surrounding rock of roadways owing to the creep and strain softening was avoided by the second support with large rigidity and high strength.And then,the circumferential stress was decreased,the radial stress was increased,and the optimization stress state would be obtained.The rock mass stress was thus transformed into the long-term strength and stable state with the viscous deformation stopped.