Case Study of Underground Shield Tunnels in Interchange Piles Foundation Underpinning Construction

Chengran Zhang,Bing Zhu,Yujia Zhao,Zhen Zhang

doi:10.3390/app11041611

Abstract

Technology of shield tunneling has been widely used in modern city subway system building, however, due to the limit of urban construction land resources, it is inevitable for the new building structures conflicted with existing one. Thus, it is essential to taking correct measures to guarantee the safety of existing structure. In this case, a typical case of metro shield tunnel crossing through city overpass bridge piles underpinning construction project is studied by the numerical method and site field monitoring. According to the existing overpass bridge structure, geological conditions and site operation environment, a suitable construction method of piles foundation underpinning plan for this project is adopted. In order to ensure the structure safety of the existed overpass bridge during the pile foundation underpinning construction, a numerical simulation model is established which takes the whole foundation underpinning structure and construction steps into consideration. The numerical simulation result shows that the stress and the settlement of the piles foundation underpinning structure is reasonable. After the comparing of the site monitoring data with the numerical model simulation results, it is found that the site settlement and stress results are highly consistent with the calculated results, and it proves the feasibility of the piles foundation underpinning construction scheme. Eventually, the site gauging settlement data of the overpass pier and the pile cap indicate that the original overpass structure is barely affected by the shield tunnel construction, the construction method can provide reference and experience for the future similar projects.

Highlights

IntroductionThe rapid growing population puts great pressure on urban traffic system, especially in those cities and gradually becomes a bottleneck hindering the development of urban construction
In terms of shield tunnel crossed through the existing bridge piles foundation area in this project a feasible and safety foundation underpinning scheme is carried out, according to the field monitoring data and numerical simulation results, the following conclusions are drawn: 6. Conclusions
In terms of shield tunnel crossed through the existing bridge piles foundation area in this project a feasible and safety foundation underpinning scheme is carried out, according to the field monitoring data and numerical simulation results, the following conclusions are drawn: 1

Summary

Introduction

The rapid growing population puts great pressure on urban traffic system, especially in those cities and gradually becomes a bottleneck hindering the development of urban construction. In order to alleviate traffic pressure, many central cities began to develop their own rail transit system especially the metro tunnel. The new planning metro line often needs to cross through the old city district which already has a large number of existing structures, such as bridges, railways, roadways, buildings, etc. Those problems exist in almost all the new emerging cities all over the world and are huge challenges to the urban subway transportation development

Methods

Discussion

Conclusion