基于FLAC3D软弱围岩隧道管棚预加固措施研究

以峨眉至汉源高速公路某隧道为依托，基于三维有限差分软件FLAC3D，建立数值模型，对管棚预加固支护体系进行模拟分析。结果表明:管棚预加固支护体系对控制围岩变形有较好的效果，但不同的管棚长度和角度加固效果差别不大；管棚长度和角度越大，挠度越大，整个预加固支护体系及隧道支护结构体系安全性越低；结合经济性和安全性综合考虑，管棚加固长度宜控制在20 m左右，仰角约为2°。

Study on the Pre-reinforcement Measures of Tunnel Shed with Soft Surrounding Rock Based on FLAC3D

Relying on a tunnel project of E'mei—Hanyuan Highway, a numerical model has been established through 3D finite difference software FLAC 3D to carry out simulation analysis to pipe roof pre-reinforcement supporting system. The results show that the pipe shed pre-reinforced support system has a good effect on controlling the deformation of surrounding rock, but the reinforcement effect has little difference with different pipe shed lengths and angles. The greater the length and angle of the pipe shed are, the greater the deflection of the pipe shed is, the lower the safety of the whole pre-reinforced support system and tunnel support structure system are. Considering both economy and safety, the length of pipe shed reinforcement should be controlled at about 20 m and the angle should be about 2°.