Bridges with known deficiencies often need to be kept in service due to a critical role in a heavy loaded transport infrastructure. Closing or traffic diversions are often judged unacceptable. The current project is aimed at critical bridges specifically with known deficiencies with the purpose of securing the functionality and the safety using an innovative smart system for monitoring and condition assessment.

The overall aim is to develop an integrated system for monitoring, data transfer, condition assessment and decision support for critical bridges. The project has three parts where the first comprise (i) wireless sensor networks and energy harvesting. Important issues are node synchronization, compressive sensing and energy harvesting from electromagnetic backscatter and bridge vibrations. The purpose is to send data to (ii) cloud based services. This is where the application interface, storage, and visualization of results are treated. Through the cloud based service, data is collected for (iii) bridge assessment and maintenance planning. Data from monitoring provide information for condition assessment using machine learning and probability based methods. As a further development, this result can be used to support decisions on remedial actions and maintenance. The result is again distributed using cloud based services.

The issues listed above require theoretical studies and practical tests. An integration of the different parts will be performed on the Old Lidingö Bridge in Stockholm. The division of structural engineering and bridges at KTH is engaged to perform a conventional long term monitoring campaign on the bridge enabling the possibility to test more innovative solutions included in the current project.