Seismic performance evaluation of a tall tower structure with integrated heat-absorbing and air-cooling capabilities: IDA based seismic fragility analysis

Abstract

The heat-absorbing tower is a novel tall power generation structure, with limited global application to date. Unlike traditional towers, which primarily serve as platforms for deploying large mass absorbers to capture reflected sunlight for electricity generation, the heat-absorbing and air-cooling (HAAC) tower is an innovative concept. It features an internally hollow design with strategically placed air inlets and outlets, and a substantial mass positioned at the top. This novel configuration not only supports absorber deployment for sunlight capture but also integrates indirect air-cooling capabilities, thereby achieving multifunctionality in infrastructure. To investigate the seismic performance of the proposed HAAC tower, assess its vulnerability, and support safety enhancement in sustainable and multifunctional infrastructure, a seismic fragility evaluation method based on incremental dynamic analysis (IDA) was adopted. A validated finite element model in ABAQUS, correlated with scaled shaking table tests, assessed 11 earthquake records across 22 intensity levels, resulting in over 242 case studies. Five intensity measures (IMs) were used: PGA, S_a(T₁,4 %), PGV, S∗ (a modified S_a accounting for post-yield period elongation), and S₁₂ – (spectral acceleration for the first two modes). Two damage measures (DMs): θ_max (maximum inter-story drift) and θ_top (top drift), were employed in IDA and fragility analysis. Results indicate that S∗ exhibits the strongest correlation to DMs, followed by PGV, PGA, S₁₂ and S_a(T₁,4 %). Using θ_max as the DM parameter reveals higher structural demands, indicating an increased likelihood of reaching critical limit states compared to θ_top. The findings suggest that the proposed HAAC tower exhibits good seismic performance, supporting the enhancement of safety and the development of multifunctional infrastructure within sustainable infrastructure.