软弱夹层对隧道围岩稳定性影响规律研究

宜巴高速公路石门垭隧道具有地质条件复杂、围岩软硬交替、高地应力等特点,施工过程中常发生围岩层状剥落、侧墙滑塌等现象,严重威胁隧道施工安全。为确保施工安全,有必要采取一些措施为实际施工提供技术指导,采用FLAC^3D有限差分法分析软件,模拟分析了隧道含不同倾角及位置的软弱夹层时围岩的稳定性,通过分析围岩位移场、塑性区及应力场的分布特征,得出了软弱夹层倾角及位置对隧道围岩变形、破坏区及应力分布的影响规律。所得结论可为同类隧道的设计、施工和研究提供借鉴和参考。

Influence of Weak Interlayer on Stability of Tunnel Surrounding Rock

Shimenya tunnel of Yiba Highway was constructed at the site with complex geological condition, high ground stress and soft and hard alternate rock. The phenomena of sidewall slumping and surrounding rock’s lamellar exfoliation appeared often during the tunnel construction process, which posed a serious threat to the construction safety, so it is necessary to perform some technological guidance to assure the construction safety. The surrounding rock stability of tunnel containing weak interlayer with different dip angle and position were simulated by the finite difference software FLAC^3D, and the distribution of displacement, plastic zone and stress field were analyzed, then the influence law of the dip angle and position of weak interlayer to the distribution of displacement, plastic zone and stress field was obtained. The conclusion can be used as reference for the design, construction and research of similar tunnels.