开挖工况对偏压连拱隧道结构及上覆山体稳定性的影响

Effects of the construction sequence of an uneven-pressured double-arch tunnel on the stability of the tunnel structure and the overlaying massif

文章采用弹塑性有限元数值模拟,对不同开挖工况下地形偏压连拱隧道围岩及主体结构的应力场、位移场、破坏区分布进行了分析,研究了开挖工况对隧道上覆山体稳定性的影响。分析表明,当先开挖浅埋侧隧道时,围岩、结构及上覆山体稳定性都要优于先开挖深埋侧隧道的方式,其计算结果可为同类隧道的设计、施工提供有益的参考。

By means of elasto - plastic finite element numerical simulation, distribution of stress field, deformation field and plastic zones in surrounding rock and lining structure are analyzed for an uneven - pressured double - arch tunnel in different construction stages. The effect of construction sequence on the stability of overlaying massif is also studied. Computed results show that when the shallower side of the tunnel is first excavated, the stability of surrounding rock, lining structure and overlaying slope are better guaranteed than in the case when the deeper side is first excavated. The results can be taken for reference bv the design and construction of similar projects.