Permit Vehicle Routing Using Reliability-Based Evaluation Procedures

Abstract

The works carried out within the framework of the development of an automatic system for permit vehicle routing on the Spanish National Highway network are described. The focus is on the methodology adopted for analysis of the old existing bridges. Because information about bridge properties (geometry, material strength) and design live load is unknown, the evaluation procedure combines the information provided by in situ measurements and inspection with a reliability-based evaluation. The reliability index for the most critical limit states derived from the maximum effects due to actual traffic on the bridge is adopted as the comparison value to define a passage criterion. Any permit crossing the bridge alone or with traffic restrictions leading to a lower reliability index will not be allowed on the bridge. The actual traffic load is obtained from existing traffic records using a model of traffic flow. The method is applied to 10 bridges fully representative of the old and nondocumented bridges most often encountered on Spanish highways. The final result is definition of the standard permits as presented in Eurocode 1 that are allowed on the bridge. From the most unfavorable permit, a criterion is derived concerning the actual vehicle permits.