Discrete Element Analysis of the Excavation Disturbance of Cross-River Twin-Tunnels on the Surroundings
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The increasing number of twin-tunnels constructed in river-crossing subway traffic compels the designers to explore its dynamics performance in the excavation progress. The characteristics of particle accelerations of the granular medium in the surroundings are the important factors to reflect the excavation disturbance. In the construction process of the twin-tunnels, the excavation of the second tunnel (named tunnel_2) will be conducted when the first tunnel (named tunnel_1) is stable. In this paper, a three-dimensional scale model of the cross-river twin-tunnels is established utilizing the discrete element method (DEM) with PFC3D, the model aims to investigate the influence of the twin-tunnels construction on the surroundings. The numerical results show that the accelerations of the particles in the surroundings around tunnel_2 are larger than those around tunnel_1 both in horizontal and vertical directions. Kinetic energy transfers as a transverse wave and is dissipated by the friction resistance and the damping effect as the transmission distance increasing in the surroundings.
KeywordsTwin-tunnels Excavation disturbance Particle acceleration Discrete element method
The project was financially supported by the National Natural Science Foundation of China (No. 51408450) and the Fundamental Research Funds for the Central Universities (WUT: 2017-YB-014; 2017IVB079).
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