断层影响下全断面开挖法水平层状隧道围岩稳定性分析OA
Analysis of Rock Mass Stability in Horizontally Layed Tunnels by Full-face Excavation Method Under Fault Influence
水平层状围岩隧道穿越断层破碎带时,因围岩结构面黏结力弱、力学性能差,易引发围岩失稳,进而增加施工风险与难度.该研究以梧桐山3车道小净距双洞隧道工程为依托,采用3DEC离散元数值模拟与现场监控量测相结合的技术方法,系统分析60、90、120 ° 3种断层倾角对围岩位移的影响规律,探究1.5、2.0、2.5 m 3种注浆加固圈厚度的工程应用效果,并通过现场监测验证数值模拟结果的可靠性.研究结果表明:围岩垂直位移集中于拱顶、拱底部位,水平位移集中于拱腰、拱脚部位,且均沿隧道中轴线呈对称分布,围岩变形曲线呈现"稳定—攀升—峰值—速降—稳定"的五阶段演化规律.不同断层倾角对围岩稳定性影响差异显著,其中90 °垂直断层围岩变形最小,120 °大倾角断层围岩变形最剧烈;超前注浆加固可分散围岩变形,2.0m注浆加固圈实现了变形控制效果与工程经济性的最优平衡,较无注浆工况,洞周围岩位移量平均降低58.06％.现场监控量测结果显示,注浆加固后洞周围岩垂向位移量控制在20 mm以内,拱腰收敛值控制在2.5 mm以内,数值模拟值与现场监测值的相对误差均≤5％,验证了所建数值模型的可靠性及超前注浆加固方案的工程适应性.
When the horizontal layered rock mass tunnels pass through the faulted zones,the construction risks and difficulties were increased due to the rock mass instability caused by weak cohesion and poor mechanical properties.Based on the three-lane,small-clearance twin-bore tunnel project of Wutongshan,a combined approach of 3DEC discrete element numerical simulation and on-site monitoring measurements was applied to systematically analyze the influence patterns of three fault inclinations(60 °,90 °,and 120 °)on rock mass displacement and investigate the engineering application effects of three grouting reinforcement ring thicknesses of 1.5 m,2.0 m,and 2.5 m.The reliability of numerical simulation results was verified through on-site monitoring.Research findings indicate that vertical rock mass displacement concentrates at the top and bottom of the arch,while horizontal displacement clus-ters at the waist and foot of the arch,both symmetrical distributed along the central axis of the tunnel.Rock mass deformation time history curves follow a five-stage evolutionary law of"stabilization-rise-peak-rapid decline-sta-bilization".Different fault dip angles have significant difference of the impact on surrounding rock stability.The de-formation of 90 ° vertical faults surrounding rock was minimal and deformation of 120 ° steeply dipping faults was the most severe;Advance grouting can effectively disperse rock mass deformation.The 2.0 m grouting reinforcement ring got the optimal balance between deformation control and engineering economy,average reduced by 58.06％than the non-grouting scenario of surrounding rock in the tunnel.Field monitoring data revealed that post-grouting vertical displacement of surrounding rock remained within 20 mm,with arch sag convergence remained with in 2.5 mm.The relative error between numerical simulation values and field measurements was ≤5％,validating the reliability of the developed numerical model and the engineering applicability of the advance grouting reinforcement scheme.
刘渤
中铁十八局集团第一工程有限公司,河北涿州 072750
交通工程
水平层状围岩断层破碎带围岩稳定性围岩位移变形超前注浆加固
Horizontal layered rock massfaulted fracture zonerock mass stabilitysurrounding rock displacement and deformationadvance grouting reinforcement
《市政技术》 2026 (2)
155-164,10
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