The analysis of the optimal scalar and vector intensity measurements for seismic performance assessment of deep-buried hydraulic arched tunnels

Abstract

The selection of optimal intensity measures (IMs) has been recommended for generating the seismic demand models with different probabilities by researchers since the seismic IMs are closely associated with earthquake risks and structural safety. However, the seismic design code (mainly for aboveground structures) and dynamic analysis of underground structures conventionally employ the peak ground acceleration (PGA) as an optimal IM. In this paper, the research is to identify the optimal scalar and vector IMs in the fragility investigation of deep-buried hydraulic arched tunnels using the finite element method. A refinement process was performed to determine the optimal scalar IMs by comprehensively comparing their correlation, efficiency, practicality, proficiency, and sufficiency among the examined IMs. Furtherly, the optimum vector IMs were also developed, followed by the three different scalar IMs. Eventually, the differences between the fragility curves of the tunnel produced using the optimal scalar and vector IM were compared. The generated vector fragility surface can be used to estimate the seismic fragility of identical hydraulic tunnels in an approximative manner.

Keywords

• Intensity measure
• Hydraulic tunnels
• Examine
• Fragility curve
• Fragility surface