巷道围岩应力壳力学特征与工程实践

综合采用数值模拟、理论分析和现场观测,深入研究了巷道围岩力学特征及其对围岩稳定性的影响规律。研究发现,巷道开挖后围岩存在连续包络的高应力束组成的应力壳,巷道处于应力壳内的低应力区,巷道围岩矿压显现受控于应力壳的存在及其空间演化;巷道围岩应力壳的空间分布对巷道围岩稳定性有关键性影响,且存在"稳定"和"非稳定"两种形态,维护巷道围岩稳定性的实质是保证巷道围岩应力壳形态的稳定;通过科学的巷道布置和有效的支护手段"控制围岩最小变形",优化围岩应力壳形态是保证巷道围岩稳定性的关键所在。研究和工程实践均表明:巷道轴向与最大水平主应力方向平行时易维护,在于巷道围岩中易形成稳定态应力壳;两者垂直时巷道难于维护,在于巷道围岩中易形成非稳定态应力壳。揭示了最大水平主应力方向对巷道围岩稳定性影响的内在力学本质。

Mechanical characteristics and practical application on stress shell of roadway surrounding rock

The mechanical characteristics of roadway surrounding rock stress shell and its effects on the stability of roadway surrounding rocks were investigated using the integrated research methods of numerical simulation,field measurement,and theoretical analysis.The results show that the stress shell composed of continuous concentrated stress appears in the roadway surrounding rocks after the excavation of roadway.Roadway lies in the low stress zone under stress shell,and the strata behaviors of roadway are controlled by the surrounding rock stress shell and its spatial evolution.The spatial distribution shape of roadway surrounding rock stress shell have a decisive influence on the stability of roadway surrounding rocks,and also there exists in two forms:stable and unstable.The stability control of roadway surrounding rock should be premised on guaranteeing the stability of roadway surrounding rock stress shell.Controlling the minimum deformation of roadway surrounding rocks through scientific roadway layout and effective supporting measures is a key to optimize the shape of surrounding rock stress shell and guarantee the stability of roadway surrounding rocks.Research and engineering practice all indicate that the direction of the maximum horizontal principal stress has an important influence on the evolution of roadway surrounding rock stress shell and the stability of surrounding rocks.When the roadway axial direction is parallel to the direction of the maximum horizontal principal stress,a stable stress shell easily exists in roadway surrounding rock,and the roadway is easy to be maintained.When the roadway axial direction is vertical to the direction of maximum horizontal principal stress,an unstable stress shell easily exists in roadway surrounding rock,and the roadway is difficult to be maintained.