Techno Press
Techno Press

Earthquakes and Structures   Volume 15, Number 6, December 2018, pages 655-665
DOI: http://dx.doi.org/10.12989/eas.2018.15.6.655
 
Use of large-scale shake table tests to assess the seismic response of a tunnel embedded in compacted sand
Hao Zhou, Xiaoyang Qin, Xinghua Wang and Yan Liang

 
Abstract     [Full Text]
    Shield tunnels are widely used throughout the world. However, their seismic performance has not been well studied. This paper focuses on the seismic response of a large scale model tunnel in compacted sand. A9.3 m long, 3.7 m wide and 2.5 m high rigid box was filled with sand so as to simulate the sandy soil surrounding the tunnel. The setup was excited on a largescale shake table. The model tunnel used was a 1:8 scaled model with a cross-sectional diameter of 900 mm. The effective shock absorbing layer (SAL) on the seismic response of the model tunnel was also investigated. The thickness of the tunnel lining is 60 mm. The earthquake motion recorded from the Kobe earthquake waves was used. The ground motions were scaled to have the same peak accelerations. A total of three peak accelerations were considered (i.e., 0.1 g, 0.2 g and 0.4 g). During the tests, the strain, acceleration and soil pressure on the surface of the tunnel were measured. In order to investigate the effect of shock absorbing layer on the dynamic response of the sand- tunnel system, two tunnel models were set up, one with and one without the shock absorbing layer of foam board were used. The results shows the longitudinal direction acceleration of the model tunnel with a shock absorbing layer were lower than those of model tunnel without the shock absorbing layer, Which indicates that the shock absorbing layer has a beneficial effect on the acceleration reduction. In addition, the shock absorbing layer has influence on the hoop strain and earth pressure of the model tunnel, this the effect of shock absorbing layer to the model tunnel will be discussed in the paper.
 
Key Words
    large-scale model tunnel; double shake table test; dynamic soil pressure; shock absorbing layer
 
Address
Hao Zhou, Xinghua Wang and Yan Liang: Department of Civil Engineering, Central South University, Changsha 410075, China
Xiaoyang Qin: Department of Civil and Environmental Engineering, University of Auckland, New Zealand
 

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