Print Email Facebook Twitter Advancing Shallow Tunnel Construction in Soft Ground Title Advancing Shallow Tunnel Construction in Soft Ground: The Pipe-Umbrella Box Jacking Method Author Jiang, Xi (The Hong Kong Polytechnic University) Zhang, X. (TU Delft Geo-engineering) Zhang, Xiao (Shanghai Urban Construction Municipal Engineering (Group) Co. Ltd) Long, Luyuan (Student TU Delft) Bai, Yun (Tongji University) Huang, Baoshan (University of Tennessee) Date 2024 Abstract The development of modern cities has often led to increased traffic congestion and limited usable space. One effective solution to these problems is to construct roadway tunnels, which can expand urban space and alleviate traffic congestion. However, building large underpass tunnels in urban areas, especially in soft ground, presents technical challenges owing to its extensive environmental disturbance. The pipe-umbrella box jacking method offers a promising solution to these challenges as this method does not require breaking the ground from the surface or disrupting surface traffic. This study reviews the key techniques of the pipe-umbrella box jacking method for constructing large rectangular tunnels with small burial depths in soft ground. The study focuses on three main technical issues: pipe umbrella installation, soil face excavation, and box jacking control. Furthermore, two tunnel projects in Shanghai, China, are presented as case studies to showcase the construction challenges and countermeasures during box jacking tunneling with pipe-umbrella. Practical construction experience has revealed that the installation of the pipe umbrella before box jacking serves as an effective method of ground pre-support. However, its performance can be influenced by factors such as pipe installation deviation and inter-pipe connection design. Both open-face steel grid extrusion (SGE) shields and closed-face earth pressure balanced (EPB) shields can be used for soil excavation during box jacking, with different work modes resulting in distinct ground deformation patterns. Additionally, lubrication grouting has been found to effectively reduce friction resistance and affect vertical ground deformation. The study also examines the lessons learned from case studies and proposes optimization measures. This study can serve as a valuable reference for the tunneling industry, providing insights into the pipe-umbrella box jacking method and its application in constructing large rectangular tunnels in soft ground. Subject Box Jacking TunnelEPB ShieldPipe UmbrellaSGE ShieldSoft Ground To reference this document use: http://resolver.tudelft.nl/uuid:c9882917-ff45-49a4-a020-d6bb963b6f99 DOI https://doi.org/10.1177/03611981231225430 ISSN 0361-1981 Source Transportation Research Record Part of collection Institutional Repository Document type journal article Rights © 2024 Xi Jiang, X. Zhang, Xiao Zhang, Luyuan Long, Yun Bai, Baoshan Huang Files PDF jiang-et-al-2024-advancin ... thod-1.pdf 1.26 MB Close viewer /islandora/object/uuid:c9882917-ff45-49a4-a020-d6bb963b6f99/datastream/OBJ/view