溶槽地段双跨连拱隧道的结构计算与分析

Structural calculation and analysis for double-arch tunnel in water-eroded groove

双跨连拱隧道以设置地基梁的方式穿过大型溶槽地段。根据地基梁与隧道结构的关系并结合施工的实际情况,确定计算模式与作用荷载;讨论连续跨越不同地基弹性地基梁的受力状态,同时对仰拱的作用及中墙在隧道结构中的重要性进行分析。研究结果表明2种不同地基介质的交界处是地基梁的最危险点,容易发生剪切与拉裂破坏;溶槽充填物的物理性质对地基梁具有显著的影响,充分考虑充填物的承载能力是合理的;仰拱能明显改善衬砌结构的受力状态,但对分散地基梁的荷载作用不大;中墙是隧道结构的关键部位,对其在施工过程中的偏压状态,应该采取工程措施予以改善。

The double-arch tunnel passes through a big water-eroded groove by setting foundation beam method. According to the relationship between foundation beam and tunnel structure and scene case, the calculated pattern and action load were determined; internal force states of elastic foundation beam which continuously spanned different foundations were discussed, and the action of invert and the importance of middle wall were analyzed. The results show that the interface of the two different foundation mediums is the most dangerous point of foundation beam where shear damage and ripping damage happen easily; the physical property of filling matter in water-eroded groove has distinct influence on the foundation beam, so it is reasonable to consider fully the carrying capacity of filling matter; setting invert can obviously improve the internal force state of tunnel structure, but it has little effect on sharing the load of foundation beam; the middle wall is the key part of tunnel structure, and the engineering measure should be taken to improve its partial pressure state in construction process.