渝利铁路高填方深基础明洞结构力学特性研究

Study on Mechanical Characteristics of Open Cut Tunnel Structure with High Fill and Deep Foundation in Chongqing-Lichuan Railway

受城市规划影响,渝利铁路以桥改隧跨越丰都斜南溪沟谷,为典型的高填方深基础明洞案例。本文研究制定了沟谷中先建造大体积混凝土隧道坝基,再在坝基上修建明洞,最后在明洞上方超厚回填土至规划标高的技术方案。并采用理论计算和数值分析,系统分析了混凝土坝基、双层明洞衬砌、填土在不同施工步中的变形和内力。分析结果表明,混凝土坝基、明洞、填土在施工和运营阶段均整体稳定,明洞内衬的施作时机对内、外衬砌内力的影响较大,应结合工期综合考虑。研究结论可为类似明洞隧道施工提供参考。

Under the influence of urban planning,Chongqing-Lichuan Railway is a typical case of open cut tunnel with high fill and deep foundation,in which the tunnel scheme instead of the bridge scheme is used to cross the Fengdu Xie nanxi Valley.This paper develops a technical scheme that firstly the mass concrete tunnel dam foundation is built in valley,then the open cut tunnel is built on the dam foundation and finally the super thick soil is backfilled to the planned elevation on the open cut tunnel.The theoretical calculation and numerical analysis is used to analyze systematically the deformation and internal force of concrete dam foundation,double-layer open tunnel lining and filling in different construction steps.The analysis results show that the concrete dam foundation,open cut tunnel and fill are all stable in the construction and operation stages,and the construction timing of the open cut tunnel lining has a greater impact on the internal and external lining forces,which should be considered in combination with the construction period.The research conclusion can provide reference for similar open tunnel construction.