Structural evaluation updating based on quality control and proof loads

Abstract

In a context of limited available resources, the structural evaluation of bridges is important to avoid the high costs of replacement and repair. As a rational evaluation criterion, the reliability of structures based on probabilistic theories provides an accurate estimate of the current strength and the remaining life time. It also represents an effective approach for analysing structural reliability under uncertainties in parameter estimates during the service life of designed and existing structures, especially during the construction.Where new information concerning the actual bridge conditions is available, which is unknown in the design phase. The certificates of material properties, measurements of actual bridge geometry, collection load data, and results of proof load testing are the major resources of this information. The extra information unknown in the design phase could be used to reduce some uncertainties related to the bridge member resistance and load parameters entering the evaluation process.The aim of this study is twofold: (a) taking into account the uncertainties ofstrength parameters, by presenting some approaches for the efficient inclusion of quality control and proof loads in the structural reliability assessment process.The results of these approaches reveals the actual safety margins in the structure and permits to avoid either unnecessary reinforcement operations or unjustified reduced load limits.