Repurposing existing surveillance infrastructure for post-earthquake performance-based structural health monitoring

Purpose This research aims to examine the feasibility of repurposing existing ceiling-mounted CCTV cameras for post-earthquake structural health monitoring by estimating inter-story drift. The motivation is to address the scalability gap of conventional sensor-based monitoring, where dedicated-sensor installation and maintenance requirements leave most buildings uninstrumented. Design/methodology/approach A video-based drift estimation pipeline is implemented using a commercial CCTV camera configuration and validated through laboratory shake-table testing. Camera-derived displacement time histories are compared against reference measurements from a laser displacement sensor. To characterize practical operating limits for real deployments, performance is evaluated under representative surveillance-camera acquisition and encoding constraints. Findings The proposed approach accurately tracks lateral displacement over earthquake-relevant drift levels, demonstrating sub-millimeter accuracy under typical surveillance-camera settings and maintaining reliable drift-based damage screening within a practical range of camera configurations. As acquisition and encoding constraints become more severe, displacement accuracy degrades and tracking robustness can be reduced. Originality/value This work provides evidence that widely deployed surveillance infrastructure can serve as a cost-effective and scalable monitoring layer for rapid post-earthquake building screening. Beyond demonstrating feasibility, it offers deployment-oriented guidance on selecting surveillance-camera operating settings to support drift-based assessment without dedicated instrumentation.