节理岩体隧道的稳定性分析

Stability Analysis of Tunnels in Jointed Rock Masses

由于节理、断层等不连续面的存在造成岩体变形的不连续性,并且对岩体变形、应力等力学行为造成重要影响。文章对已有的非连续变形分析程序进行了两点改进,采用改进的SSOR-PCG方法并且加入了位移收敛准则;应用改进后的程序对某公路隧道进行了稳定性分析,通过对关键点位移的监测优化了开挖顺序,结果表明对于左右洞室隧道一次性开挖比分步开挖能减少对围岩的扰动;然后通过对关键点位移的监测,分析了锚杆的锚固效应,优化了支护参数。

Joints and faults may cause discontinuity of rock mass deformation, and they significantly affect the mechanical behavior of rock mass deformation, stress, and so on. In this paper, two improvements are made to the existing discontinuous deformation analysis program, i.e., the adoption of an improved SSOR-PCG method and the addition of displacement convergence criterion. A stability analysis of a highway tunnel is carried out by the improved program, and the excavation procedures are optimized by monitoring displacement of the key points. The results show that one-time excavation of a left/right tunnel causes less disturbance to surrounding rocks than excavation by steps. Based on the monitoring of key displacement points, the anchoring effect is analyzed and support parameters are optimized.