Computer-Aided Civil and Infrastructure Engineering 16(6) (2001) 444–454 INDUSTRIAL APPLICATION Computer-Based Bridge Management System for Permit Vehicle Routing Joan R. Casas* & Angel C. Aparicio Technical University of Catalunya, Civil Engineering Department, Jordi Girona 1-3, Campus Nord. Modul C1, 08034 Barcelona, Spain Abstract: The traffic of special overloaded trucks (spe- cial permits) over bridges may create structural problems not only in the time of crossing but also in the service life of the bridge (cracking in concrete bridges affecting their durability, fatigue in steel bridges, etc.). Therefore, the owner agency responsible for a bridge network should look carefully at the maximum loads acting on the bridges and the problems they may cause according to their actual condition. This article presents the work carried out by the authors concerning the possibility of passage permis- sion of overload permits in the main highway network of Spain. Most of the bridges are quite new and very well documented, but also older bridges are present whose doc- umentation is not available. The work is summarized in a bridge management system (BMS) installed on a PC. The computational model performs the structural analysis of the bridges crossed by a defined special vehicle in a quick and automatic way and compares the results with the maximum allowable actions over the bridge, the result being autho- rization or not of the passage. The computational models are developed for most common bridge types in the net- work and are of limited value for very complex structures such as cable-stayed or suspension bridges. The BMS is now in use in the complete trunk road system in Spain. The software developed has shown its usefulness in assisting bridge engineers in the decision-making process of permit passage. 1 INTRODUCTION An important effort has developed worldwide recently by different transportation agencies and departments of * To whom correspondence should be addressed. E-mail: joan.ramon.casas@upc.es. transportation to improve the decision-making process con- cerning bridge inspection, maintenance, rehabilitation, and replacement. The main goal is to optimize the always lim- ited funds available when the number of deficient and obso- lete bridges is constantly increasing. This has resulted in the development and updating of different bridge management systems (BMS) dealing with this problem. 1,3,13,18,20,23,24 However, another classic and not yet completely solved problem related to bridge management (normally not included in the standard BMS and faced by many trans- portation departments or highway agencies) is authoriza- tion concerning traffic with special permits over bridges. In fact, in order to be more competitive with other trans- portation facilities, road freight companies are increasing pressure on bridge authorities to permit higher loads on bridges. In some cases, this drives the need to apply for special overload permits in geometry and load. Despite the controlled axle load to not damage the pavement, the total truck weight and distribution among different axles are of concern regarding possible damage and consequences to the service lifetime of bridges. Permit vehicles, normally carrying heavy equipment and items that cannot be divided (e.g., girders, industrial parts, parts of nuclear power plants, etc.), must apply to the highway authority for passage per- mission (Figure 1). The bridge owner, in turn, must check the bearing capacity of all the bridges to be crossed by the special permit and must provide the additional require- ments (e.g., centric passage, no presence of normal traffic during the permit crossing, etc.) if any. The last should take into account the actual condition of the bridge derived from the results of previous inspections and assessments. Nor- mally, bridges with different typologies and different mate- rials, span lengths, and deck widths are present in the net- work. Therefore, the assessment for permit crossing cannot be performed automatically, and the safety assessment of © 2001 Computer-Aided Civil and Infrastructure Engineering. Published by Blackwell Publishers, 350 Main Street, Malden, MA 02148, USA, and 108 Cowley Road, Oxford OX4 1JF, UK.