Nonlinear Seismic Analysis of Ground Structure to Evaluate the Capacity of a Permanent Tunnel Lining

Abstract

ABSTRACT In this paper, in addition to the linear analysis used for typical tunnels, nonlinear seismic analysis of a tunnel has been investigated using pseudo-static method and a damaged concrete behavior model introduced in ABAQUS® software. The simulations were carried out under three conditions, free field, ovaling and racking, at two hazardous earthquake levels according to an Operation Design Earthquake (ODE) and a Maximum Design Earthquake (MDE). Then, the structural capacity curve and the behavior factor for the final tunnel lining were obtained. In order to extend the studies as well as to verify the pseudo-static analyses, seven nonlinear dynamic analyses compatible with the site under MDE conditions have been performed. The results showed that the tunnel lining procedure created limited tensile cracks under compression. At the bottom corners of the tunnel structure, the resultant stresses in the tunnel lining under two earthquakes caused failure and created tensile cracks. Therefore, it was necessary to reinforce the lining at corners. Comparison between different nonlinear time history seismic analysis and pseudo-static methods indicated that the pseudo-static methods resulted in 10–30% less acceleration than the average results obtained from time history analysis.