戴云山隧道燕尾段施工数值仿真分析

国内外燕尾式隧道的修建起步较晚，相应的技术难度较大，缺少施工经验和技术标准。利用大型有限元软件对新建向莆铁路戴云山隧道燕尾段工程开挖进行了仿真模拟，通过对围岩应力场、位移场和支护体系受力特点的分析研究，指出大跨段拱顶下沉和拱底回弹较大，连拱段中墙上方岩体最为脆弱、中墙偏移、墙身偏压、墙底受拉，小净距段中夹岩柱承受压力较大。针对上述问题,提出了相应的施工建议与对策，对燕尾段现场施工具有一定的指导意义。

Numerical Simulation on Excavation of Swallow tailed Section of Daiyunshan Tunnel

The building of the swallow tailed tunnel is little at the present, which leads to the lack of construction experience and technical specification. The process of the swallow tailed tunnel excavation is simulated by employing numerical method in the article. According to the result of the surrounding rock stress, the displacement and the stress of primary support system, the larger vault subsidence and bottom rebound in the large span tunnel, the vulnerability of the rock above the middle wall, the shifting of the wall, the eccentric compression of the wall and the tension under the wall in the double arched tunnel, and the high press stress of the shared rock in the neighborhood tunnel, the measures corresponding to the above mentioned problems are put forwards, which can make a reference for constructing swallow tailed tunnel.