锚杆支护对土质隧道围岩位移影响的数值分析

Numerical Analysis of Influence of Bolting on Displacement of Soil Tunnel Surrounding Rock

采用离散元法模拟了锚杆支护对土质隧道围岩位移的影响,分析了锚杆不同长度、不同间距时隧道上方围岩竖向位移的变化情况。结果表明:固定锚杆间距,锚杆越长在其加固范围内的隧道上方围岩竖向位移越小,但其加固范围以外的隧道上方围岩竖向位移反而略有增大;固定锚杆长度,随其间距的增大隧道上方围岩竖向位移始终有增大的趋势,且拱顶围岩竖向位移大体呈对数曲线增大的趋势;锚杆最优间距随其总长度的增加而减小。

The influence of the bolting on the displacement of the soil tunnel surrounding rock was simulated by the discrete element method to analyze the change in the vertical displacement of the surrounding rock above the tunnel under different lengths and spacing of the bolt.The results showed that with fixed bolt spacing,the longer the bolt,the smaller the vertical displacement of the surrounding rock above the tunnel within the range of reinforcement,but the larger out of the range of reinforcement.With fixed bolt length,the vertical displacement of the surrounding rock above the tunnel consistently increased with the increase of bolt spacing,and it approximately increased logarithmically.The optimal bolt spacing decreased with the increase of the total bolt length.