全风化花岗岩公路隧道浅埋施工技术研究

Research on construction techniques for shallow - buried highway tunnels in completely weathered granite

摘要:

依托某在建全风化花岗岩地区公路隧道，提出了一种针对复杂地质条件下的隧道支护优化技术，并借助隧道围岩变形现场监测数据分析了支护效果。研究表明，综合采用超前小导管支护、钢拱架加固、锚杆支护、喷射混凝土及水文控制等技术，能够有效减少围岩变形、提高施工稳定性，并解决地下水涌水问题。通过优化支护密度、调整开挖顺序以及加强排水系统设计，支护方案的改进使隧道拱顶下沉量减少了约38.1%，周边收缩值降低了47.9%。该优化方案有效增强了围岩稳定性，控制了水文条件的影响，改善了施工环境。研究成果为类似地质条件下的公路隧道施工提供了技术参考，并为类似隧道支护设计与施工提供参考。

Abstract:

Based on a highway tunnel under construction in a fully weathered granite area, a tunnel support optimization technology is proposed for complex geological conditions, and the support effectiveness through on-site monitoring of tunnel surrounding rock deformation is analyzed. The research indicates that the comprehensive application of advanced small pipe roofing, steel arch reinforcement, bolt support, shotcrete, and hydrological control technologies can effectively reduce surrounding rock deformation, enhance construction stability, and address groundwater inflow issues. By optimizing support density, adjusting excavation sequences, and strengthening drainage system design, the improved support scheme reduces tunnel crown settlement by approximately 38.1% and peripheral convergence by 47.9%. This optimized solution significantly enhances surrounding rock stability, mitigates the impact of hydrological conditions, and improves the construction environment. The research results provide technical references for highway tunnel construction under similar geological conditions and offer valuable insights for the design and construction of similar tunnel supports.