巷道底鼓机理数值模拟

Numerical Simulation on Floor Heave Mechanism of Roadway

在岩石破裂过程分析系统(RFPA2D)的基础上,引入岩石蠕变演化模型,考虑岩体在恒定荷载情况下,其长期强度随着时间变化,造成巷道围岩的强度与弹性模量衰减。数值结果表明,底板岩层在水平应力的作用下,出现初始变形破坏、离层,导致垂直应力降低,巷道围岩的两帮和底板出现裂纹扩展。由于岩石的蠕变特性,其底板岩层的强度和弹模随着时间增加其值不断衰减,水平应力沿底板岩层方向开始向深部岩层转移,造成巷道底板岩层在水平应力作用下不断地向巷道内鼓出,底板岩层达到最终破坏深度。

Based on the rock fracture process analysis（RFPA2D）system,it introduced rock creep evolution model,considered under the situation of constant loading,with the time changed,the long-term strength of rock caused the attenuation on strength and elastic modulus of roadway surrounding rock.Numerical result shows that,under the effect of horizontal stress,initial deformation damage and abscission layer occur to floor strata,cause vertical stress reduce and crack propagation occur on both sides and floor of roadway surrounding rock.Because of the creep characteristics of rock,value of strength and elasticity moduli of floor strata decrease continuously with the time increasing,horizontal stress begin transfer to deep rock of floor along the direction of floor strata,cause roadway floor strata bloating into roadway constantly under the effect of horizontal stress,floor strata reach to final damage depth.