ReStructure: A Wireless Sensor Network for Monitoring Temporary Earth Retaining Systems

Temporary earth retaining structures help prevent collapse during construction excavation. To ensure that these structures are operating within design specifications, load forces on supports must be monitored. Current approaches are expensive, often manual, and difficult to integrate into predictive models. We developed a wireless strain gauge suitable for harsh construction environments along with a data collection back-end that could be integrated into online predictive models. This system has been used to monitor an underground train station construction site in Singapore for 5 months. Key challenges are to ensure valid measurements, reliable wireless communication, sufficiently long battery life, and protection against weather and incidental damage. This paper describes the system design, experiences with its deployment and lessons for future developments