Analysis on the Dynamic Responses of an Overlapped Circular Shield Tunnel under the Different Vibration Loads

  • PDF / 4,519,096 Bytes
  • 14 Pages / 595 x 786 pts Page_size
  • 61 Downloads / 268 Views

DOWNLOAD

REPORT


pISSN 1226-7988, eISSN 1976-3808 www.springer.com/12205

DOI 10.1007/s12205-020-2001-2

Tunnel Engineering

Analysis on the Dynamic Responses of an Overlapped Circular Shield  Tunnel under the Different Vibration Loads Qixiang Yan Xirui Liu c

a

, Junchen Zhang

a

, Wenyu Chen

b

, Chaofan Yao

a

, Wenbo Yang

a

, Hang Chen

b

, and

Key Laboratory of Transportation Tunnel Engineering, Ministry of Education, Southwest Jiaotong University, Chengdu 610031, China Sichuan Highway Planning, Survey, Design and Research Institute Ltd., Chengdu 610041, China c General Office of Chengdu Municipal People's Government, Chengdu 610000, China a

b

ARTICLE HISTORY

ABSTRACT

Received 19 November 2019 Revised 1st 15 March 2020 Revised 2nd 19 May 2020 Accepted 25 May 2020 Published Online 17 August 2020

At present, there are many studies on the dynamic response of overlapped tunnels, but most of them are through numerical simulation. Very few has been conducted by the experimental model research and frequency domain analysis. Combined with the model test and the numerical simulation, the dynamic response of the tunnel lining structure under the action of different train speeds and different tunnel clear distances are investigated, which can remedy the deficiencies in the relevant fields and verify the accuracy of numerical simulation results. The results show that as the train speed increases, the amplitude of the energy spectra of the vibration loads decrease significantly. The tunnel response at the sidewalls is smaller than that at the tunnel crown and at the invert in the lower tunnel. As the net distance increases, the amplitudes of the acceleration frequency spectrum and the energy spectra of the lower tunnel decrease, but with a diminishing rate. The dynamic coefficients of circumferential of the upper tunnel under a train load are larger than those in the longitudinal direction in the invert.

KEYWORDS Train vibration loads Overlapped shield tunnels Dynamic response Transfer rate Dynamic coefficient

1. Introduction As the result of the complexity and diversity of urban underground pipeline network and space constraints, there will inevitably be a great deal of space-overlapped structures. The vibration response of space-overlapped structures to train loads has attracted more and more attention from researchers (Xu et al., 2011; Yan et al., 2018a; Zhang et al., 2019). Due to the wheel-rail interaction, vibration generated at the rail can propagate though the tunnel lining and surrounding soil into buried and ground surface structures. These vibrations may have significant influences on the surrounding residential areas (Connolly et al., 2016). In addition, the long-term train vibration may cause damage to adjacent underground structures (Ge et al., 2016). Various studies on the mechanism of train vibration loads have been conducted. Based on the load-sharing ratio test, Jiang (2014) proposed a train load formula using the train-slab tracksubgrade coupled vibration model. Expressions for the time-

CORRESPONDENCE