Techno-economical and practical considerations for SHM systems

Abstract

Nowadays, the increasing demand of Structural Health Monitoring (SHM) systems, either for research or specific monitoring applications, is posing several questions on their technical and economical sustainability. In general, the initial cost of a full scope and long-term SHM system is significant, but also, the operational and maintenance costs have an important role. In practice, it has been found that there is a correlation between the cost of the SHM system and its main monitoring scope, including the size and complexity of the structure to be monitored. Additional considerations must include peripheral systems (hardware and software) to process, analyze and to store data efficiently for long-term evaluations. Even though, most SHM systems are designed assuming that the benefits overweight the costs. In practice, the payback from technical knowledge, maintenance reduction costs, safety or reliability, are not easy (if not impossible) to quantify. While most engineers and researchers are thinking on sophisticated techniques and more efficient or accurate sensors, the users concerns are on practical and economic issues to justify the initial investment and the cost to operate the monitoring system. Cost-benefit or cost-efficiency analysis is not an ordinary practice for researchers, but is becoming a standard requirement for infrastructure investment projects. In this document, the guidelines for the preparation and presentation of cost and benefit analysis of investment programs and projects required by the Mexican Government, are used to evaluate some specific SHM systems of highway bridges. In general, it is found that the main challenge for these analyses is the availability of conclusive information to justify the sustainability of the monitoring projects, especially those which are related to the benefits.