Journal of Shanghai Jiao Tong University ›› 2022, Vol. 56 ›› Issue (9): 1227-1237.doi: 10.16183/j.cnki.jsjtu.2022.006

• Naval Architecture, Ocean and Civil Engineering • Previous Articles     Next Articles

Anti-Uplift Portal Frame in Control of Underlying Tunnel Deformation Induced by Foundation Pit Excavation

WU Huaina, FENG Donglin, LIU Yuan(), LAN Ganzhou, CHEN Renpeng   

  1. Research Center of Underground Space Advanced Technology;Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education;College of Civil Engineering, Hunan University, Changsha 410082, China
  • Received:2022-01-07 Online:2022-09-28 Published:2022-10-09
  • Contact: LIU Yuan


The excavation of foundation pit above the existing metro tunnel inevitably leads to the uplift of the tunnel. As an anti-uplift measure, the anti-uplift portal frame is still lack of research. Based on a foundation pit excavation project colinear with tunnel for long-distance, the excavation influence on the underlying shield tunnel during the construction process of anti-uplift portal frame and the foundation pit excavation was studied via numerical simulation. The interaction mechanism between the anti-uplift portal frame and ground as well as the anti-uplift effect were analyzed. Finally, a structural optimization design was proposed based on the simulation. The results show that the tunnel may be uplifted due to the shaft excavation during the construction of the anti-uplift portal frame and the uplift can be effectively restricted by backfilling and sectional excavation. Compared to the excavation without the anti-uplift portal frame, the uplift value of the tunnel decreases from 19.5 mm to 15 mm because of the restriction of the anti-uplift portal frame. The connection between the slabs and piles are weak positions of the structure due to the stress concentration and it is necessary to do a local reinforcement treatment in the connection.

Key words: anti-uplift portal frame, pile-soil interaction mechanism, construction disturbance, anti-uplift mechanism, numerical simulation

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