管幕结构法隧道下穿南京城墙设计方案研究

Study on the Design Scheme of the New Tubular Roof Tunnel Passing Beneath Nanjing City Gate

以南京建宁西路过江通道江南连接线主线隧道东延工程下穿南京城墙仪凤门段节点为例,研究浅埋矩形隧道下穿南京城墙的设计方案。针对节点开挖断面大、城墙变形控制标准高等特点,通过工法比选,推荐采用管幕结构法,并提出相应的设计方案。结合设计方案,利用FLAC3D三维模型,对城墙、城楼稳定性进行分析,确定影响城墙、城楼变形的主要工况,并给出防护措施。研究成果可为其他下穿城墙等国家级保护文物的工程提供参考。

This paper presents a design scheme for the shallow rectangular tunnel passes beneath the Nanjing city gate based on the West Jianning Road Channel Project.Mining method is adopted due to the limitation of construction condition.According the comparison of construction method,new tubular roof method is used based on the characteristics of large excavation section and high deformation control standard of city gate,and corresponding design scheme is put forward.Numerical calculation like FLAC3d is used to analyze the stability of city wall and tower.The main working conditions affecting the deformation of city wall and tower are determined,and preventive or protective measures are proposed.Findings from this paper can provide guidance for other projects passing beneath the protection of national cultural relics(e.g.city gate).