非全长锚固单元体锚杆滑脱失效研究

Research on Investigation of Slipping Mechanism of Rock Bolt in Non-full Length Anchorage Unit

基于颗粒微观接触模型建立了非全长锚固单元体模型,分析了非全长锚固单元体锚固长度和围岩应力对滑脱失效的影响,并研究了锚固段微观破坏机制。结果表明:锚固单元体内裂隙发育由表及里逐渐向锚固深部扩展。剪切裂隙主要分布在5倍锚孔孔径范围内。随着锚固长度增加,锚固单元体内总裂隙发育密度线性递减;随着围岩应力增加,各裂隙发育总量逐渐减少,且随围岩应力呈线性递减趋势。

Based on the microscopic contact model of particles,a non-full length anchoring unit model was established.The effects of anchor length and surrounding rock stress on the failure of the non-full length anchoring unit were analyzed.The micro-destructive mechanism of the anchoring section was studied.The results show that the development of fissures in the anchoring unit gradually extends from the surface to the depth of the anchor.The shear cracks are mainly distributed within the pore size of the 5 times anchor hole.With the increase of anchoring length,the development density of total fissures in the anchoring unit decreases linearly.With the increase of surrounding rock stress,the total development of each fissure decreases gradually,and decreases linearly with the surrounding rock stress.