Seismic Assessment of Horseshoe-Shaped Tunnel Using a Pseudo-Static Approach

Abstract

The rapid expansion of the development of hydropower in geologically and seismically active areas has numerous technological risks involved. Tunnels in rock masses have different stress and deformation responses than other engineering materials due to the existence of weak planes. This paper describes the use of numerical modeling approaches to assess tunnel deformation and tunnel stability under the earthquake loading for an 8.8 m horseshoe-shaped power tunnel excavated in Vishnugarh Pipalkoti, Uttaranchal, India. In this analysis, two different approaches are used to perform pseudo-static analyzes to understand the impacts of seismicity on tunnels. The rock mass is modeled as continuum in the first approach, and the tunnel is treated as a continuum equivalent with the inclusion of critical joint sets in the second method. The present study concluded that the first approach overestimates the seismic forces generated in the liner. Hence, it is more beneficial to use an equivalent continuum-interface approach to obtain results with greater accuracy. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.