上软下硬大跨车站隧道施工方案研究

依托大连地铁二号线兴工街站,充分组合使用超前大管棚与小导管注浆、双层初期支护、增设大拱脚、拱部后期径向注浆和纵梁底岩体注浆加固多种控制措施对围岩变形进行控制。利用有限元软件对组合变形控制措施的施工效果深入分析,发现随着支护措施的逐渐增强,地表最大沉降值逐渐减小,控制效果明显;双层初期支护和增设大拱脚对控制地表沉降效果最好。结合监控量测进行现场实证变形控制效果,实测结果与数值模拟的地表沉降规律非常相近,证明了数值模拟结果的合理性。研究成果可以为此类隧道修建积累实践经验,指导今后的隧道设计与施工。

Construction Scheme Research on a Upper soft and Lower hard Ground Large Span Station Tunnel

Based on Dalian metro line two Xinggong Street station ,this paper adopted a combined control method of lead-pipe shed and small pipe grouting ,double initial support ,adding high arch foot ,arch post grouting and beam bottom rock grouting to control the deformation of surrounding rock .It used the finite element software to analyze the construction effect of combined control measures .The results showed that with the improvement of support measures ,the maximum surface settlement gradually decreases .The control effect is obvious and the double initial support and adding the big arch foot are the best for settlement control .It verifies the deformation control effect combining with the monitoring data .The measured results are very similar to the numerical simulation results ,thus the rationality of the numerical simulation re-sults is proved .The research results can provide practical experience for the construction of such tunnels ,and guide the design and construction of the tunnel in the future .