Application of the endurance time methodology on seismic analysis and performance assessment of hydraulic arched tunnels

Abstract The seismic nonlinear behavior and seismic stability of hydraulic arched tunnels remain critical issues with regard to evaluating seismic performance. Generally, evaluating the seismic performance of hydraulic arched tunnels under strong ground motions from low to high seismic intensities constitutes the basis for revealing their seismic resistance and is performed by either pushover analysis or incremental dynamic analysis (IDA). However, the abovementioned methods may have very high computational costs due to the high modeling complexity. Endurance time analysis (ETA) is a new time-history dynamic pushover methodology for assessing the seismic performance of aboveground structures. ETA gives acceptable numerical results for aboveground structures under a wide range of seismic intensities and significantly reduces the computational cost in comparison to conventional nonlinear dynamic analysis. Nevertheless, although the applicability of ETA to aboveground structures has been widely recognized, its suitability to underground structures, especially hydraulic arched tunnels, remains poorly understood. Hence, the focus of this paper is to evaluate the applicability of ETA to hydraulic arched tunnels and to perform an in-depth comparison between the results of IDA and ETA. A model of a hydraulic arched tunnel with two buried depths is first built in commercial ABAQUS software considering the nonlinear dynamic damage analysis model of fluid–structure–rock mass interaction systems. Then, IDA is employed to generate different seismic intensity results that are regarded as a benchmark for the hydraulic arched tunnel under 15 as-recorded ground motions. Subsequently, nonlinear dynamic analysis of the hydraulic arched tunnel is conducted under three ET ground motions. The findings highlight that the ETA methodology provides acceptable accuracy for engineering applications and can be implemented for the rapid nonlinear dynamic analysis and seismic performance evaluation of hydraulic arched tunnels.