偏压隧道洞口段坡体钢花管注浆加固效果分析

Analysis on the Slope Reinforcement Effectiveness of Steel Pipe Grouting in Biased Tunnel Portal Section

以某偏压隧道施作套拱初期致局部坡体滑移为研究背景,提出3种边坡加固方案进行对比分析,采用有限元法,建立相应计算模型分析在3种加固方案下边坡安全系数,侧坡总位移、有效塑性应变、最大剪应变及隧道开挖下地表竖向位移值。通过对3种加固方案对比分析表明:坡面挂网喷浆+注浆锚杆+局部坡体钢花管注浆加固后坡体的稳定性明显优于坡面挂网喷浆+注浆锚杆与坡面挂网喷浆+注浆锚杆+局部坡体注浆支护。结合现场实测验证了数值仿真中的第三种加固方案的可行性,结果表明该方案不仅提高了边坡的整体稳定性而且能最大程度减小隧道开挖对地表变形的影响,在工程中应用取得了良好的经济效应与社会效应。

Based on the background of slope slipping caused at initial arch stage of a biased tunnel,three kinds of slope reinforcement schemes are proposed for comparative analysis.The finite element method is used to establish the corresponding calculation models to analyze the slope under three kinds of reinforcement schemes in terms of safety factor,total slope displacement,effective plastic strain and maximum shear strain and vertical displacement of the ground surface under tunnel excavation.After comparisons and analysis on the three kinds of reinforcement schemes it shows that show that the stability of the slope suspended mesh gunite+grouting anchor+local steel pipe grouting reinforcement is obviously better than the suspended mesh gunite+grouting anchor and suspended mesh gunite+grouting anchor+local slope grouting support.The feasibility of the third reinforcement scheme in numerical simulation is verified by the field measurement.The results show that the program can not only improve the overall stability of the slope but also minimize the impact of tunnel excavation on the surface deformation and obtain good economic and social benefits.