采用弹塑性三维有限差分数值模拟计算的分析方法，对溶槽段、双连拱隧道偏压施工阶段结构稳定性进行了分析。研究结果表明：在弹性地基梁的跨中处是二次衬砌和中墙结构的最危险断面，容易发生拉裂与失稳破坏；溶槽充填物的物理性质对隧道结构的受力状态和稳定性有显著的影响；及时施作仰拱有利于结构的稳定，说明闭合结构对于改善结构的受力状态有显著的效果；中墙在单跨施工阶段处于不利的偏压状态，施工中应采取措施予以改善。

By adopting the calculating analysis method of elastic-plastic three-dimension FDM numeric simulation，this paper makes a simulation analysis on the structure stability of bias-pressure construction stage of a double-arch tunnel passing through a? water-eroded groove. The research result shows that the mid-span of beams is a worst section of quadric lining and middle wall, instability and ripping damage easily happen here; the physics property of filling matter in water-eroded groove has distinct influence to the internal force state of structure; setting the invert in time is favorable to improve internal force state of supporting structure, and hence makes the structure more stability; the middle wall is a key part of tunnel structure, so some engineering measures ought to be adopted to improve its partial pressure state in construction process.