Enhancing campus resilience monitoring with distributed acoustic sensing: a case study

Distributed acoustic sensing (DAS) has emerged as a powerful technology for monitoring seismic events with high spatiotemporal resolution. By using these detailed observations, proactive assessments can significantly enhance resilience through the optimization of management strategies for underground infrastructure and above-ground campus facilities. Recognizing the critical role that underground pipelines play in both subterranean systems and overall campus resilience, this study focuses on their continuous and long-term monitoring at Nanjing University Xianlin Campus, utilizing DAS technology. Our analysis involves the extraction and analysis of key parameters from a 3.8-kilometer-long underground fiber-optic cable array, including flow-induced vibrations, changes in natural frequency, and power spectral density. DAS recordings, which have been collected since February 2023, enable us to assess into the health status of the underground pipelines. The vibrations captured by DAS in response to flow serve as an effective tool for evaluating the drainage system’s capacity, aiding in forecasting flood hazards during extended periods of rainfall. Variations in natural frequency reveal key information about the structural integrity of pipelines, especially under heavy rainfall and seismic activity. Additionally, fluctuations in power spectral density offer both localized and comprehensive spatiotemporal assessments, guiding campus-wide resilience strategies. Key metrics are derived from DAS data to identify patterns of campus activity, informing the decision-making process for optimizing resilience strategies. These results highlight the potential of DAS for long-term, real-time monitoring, supporting enhanced resilience at scales ranging from individual campuses to entire urban environments.