Permit checking of overloaded customized transport vehicle based on serviceability limit state reliability of concrete bridges

To increase the authorization efficiency of overloaded customized transport vehicle (CTV), a serviceability limit state (SLS) reliability based permit checking method for concrete bridges is proposed through the optimization towards critical load effect ratio. In this procedure, the SLS reliability of crack width and the SLS reliability of concrete stress in tensile region are analyzed for reinforced concrete (RC) and prestressed concrete (PC) structures, respectively. The durability requirements and a unified reliable level can be concentrated reflected by the optimized critical load effect ratio. The results show that it is unreasonable to take a uniform target reliability index for all routes in permit checking of CTV, a stricter authorization criterion should be adopted for a higher expected authorization frequency. For a specific route level, a fluctuant variation of critical load effect ratio can be found with the increasing of bridge span. By introducing an ultimate limit state (ULS) based safety checking procedure, it is found that the SLS based permit checking criterion is crucial and determinative for the authorization of CTV instead of the ULS.