The influence of pore-fluid in the soil on ground vibrations from a tunnel embedded in a layered half-space

• Published in: Journal of sound and vibration Vol. 419; pp. 227 - 248
• Main Authors: Yuan, Zonghao, Cao, Zhigang, Boström, Anders, Cai, Yuanqiang
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 14.04.2018; Elsevier Science Ltd
• Subjects: Boundary conditions; Cylinders; Cylindrical waves; Fluid-structure interaction; Free boundaries; Groundwater levels; Half spaces; Layered half-space; Mathematical models; Moving ground water table; Numerical analysis; Plane waves; Semi-analytical solution; Soil layers; Subways; Surface vibrations; Surface waves; Thickness; Tunnel; Tunnels; Underground railways; Vibration analysis; Vibration effects; Viscoelasticity; Water tables; Semi-analytical solution; Tunnel; Surface vibrations; Layered half-space; Moving ground water table
• ISSN: 0022-460X; 1095-8568; 1095-8568
• DOI: 10.1016/j.jsv.2018.01.003

A computationally efficient semi-analytical solution for ground-borne vibrations from underground railways is proposed and used to investigate the influence of hydraulic boundary conditions at the scattering surfaces and the moving ground water table on ground vibrations. The arrangement of a dry soil layer with varying thickness resting on a saturated poroelastic half-space, which includes a circular tunnel subject to a harmonic load at the tunnel invert, creates the scenario of a moving water table for research purposes in this paper. The tunnel is modelled as a hollow cylinder, which is made of viscoelastic material and buried in the half-space below the ground water table. The wave field in the dry soil layer consists of up-going and down-going waves while the wave field in the tunnel wall consists of outgoing and regular cylindrical waves. The complete solution for the saturated half-space with a cylindrical hole is composed of down-going plane waves and outgoing cylindrical waves. By adopting traction-free boundary conditions on the ground surface and continuity conditions at the interfaces of the two soil layers and of the tunnel and the surrounding soil, a set of algebraic equations can be obtained and solved in the transformed domain. Numerical results show that the moving ground water table can cause an uncertainty of up to 20 dB for surface vibrations. •A semi-analytical solution for a tunnel embedded in a layered half-space is proposed.•The influence of hydraulic boundaries and the water table variation is investigated.•The moving water table can cause an uncertainty of 20 dB for surface vibrations.