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http://dx.doi.org/10.9711/KTAJ.2021.23.2.107

The effect of curvature at the bottom of a soft ground tunnel by numerical analysis  

You, Kwangho (Dept. of Civil and Environmental Engineering, University of Suwon)
Kim, Kangsan (Dept. of Civil and Environmental Engineering, University of Suwon)
Publication Information
Journal of Korean Tunnelling and Underground Space Association / v.23, no.2, 2021 , pp. 107-118 More about this Journal
Abstract
Due to the acceleration of road construction, the number and extension of tunnels are increasing every year. A lot of research has been done on the collapse of tunnels, but research on the invert heaving is insufficient. Therefore, in this study, a sensitivity analysis was performed using a geotechnical general-purpose program to analyze the effect of the invert curvature of a tunnel excavated on the soft ground. As a result, it was quantitatively confirmed that the stability of a tunnel was increased as the curvature of the tunnel invert was increased so that the safety factor was calculated to be large regardless of the ground conditions and the thickness of the support. In addition, it was confirmed that the stability of the tunnel was increased by reducing the convergence of the tunnel and the maximum bending stress supported by shotcrete. Therefore, when a tunnel is excavated on soft ground, it is believed that applying a curvature to the invert will increase the stability of the tunnel.
Keywords
Tunnel invert; Soft ground; Factor of safety; Curvature; Finite difference method;
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