地铁隧道下穿运营铁路框架桥的加固方案分析

Analysis on the Reinforcement Scheme of Railway Frame Bridge under the Subway Tunnel

地铁盾构隧道下穿铁路框架桥时,通常需预先对框架桥底部土体进行加固,以降低盾构施工对铁路框架桥的影响。经对加固方案分析表明,注浆加固对减小框架桥竖向沉降具有一定作用,但注浆厚度越大,对减小框架桥的竖向沉降作用并不明显;考虑到施工的便利性,在框架桥两端底部加设钢筋混凝土梁,对减小框架桥竖向沉降具有明显作用,且框架桥的部分荷载通过端梁转移至沉降槽之外的土体中,从而大大减小了框架桥的竖向沉降。

When the subway shield tunnel underpasses the railway frame bridge, it is usually necessary to strengthen the soil at the bottom of the frame bridge in advance, in order to reduce the influence of shield construction on the railway frame bridge.The analysis of the reinforcement scheme shows that the grouting reinforcement has a certain effect on reducing the vertical settlement of the frame bridge, but the larger the grouting thickness is, the effect on reducing the vertical settlement of the frame bridge is not obvious.Considering the convenience of construction, adding reinforced concrete beams at the bottom of both ends of the frame bridge has an obvious effect on reducing the vertical settlement of the frame bridge,and part of the load of the frame bridge is transferred to the soil outside the settlement trough through the end beam,thus greatly reducing the vertical settlement of the frame bridge.