Parametric study of orthotropic steel decks with open ribs using FEA

For orthotropic steel deck (OSD) bridges, the open ribs are less used because of their relatively lower torsional stiffness. However, with the design focus of OSD shifts from strength design to fatigue design, the system of open ribs shows the potential to be more considered for future projects. In this paper, a newly built OSD bridge is investigated focusing on the rib-to-crossbeam joint. Based on the in-situ measurements of the existing bridge, the numerical modeling of the whole bridge is finished. Furthermore, a simplified local model is developed focusing on the rib-to-crossbeam joint. Then, the influences of design parameters i.e. the crossbeam span and the spacing between ribs are investigated. Research results reveal that the global behavior of the bridge can be modeled. However, calculation results of points close to the connecting weld and the cope hole do not fit well with the measurements. In this case, increasing the crossbeam span will decrease the stresses of points close to the weld toe of the connecting weld. Increasing the spacing between ribs is more effective to reduce the tangent stress around the cope hole. The most unfavorable load position does not change with these two parameters.For orthotropic steel deck (OSD) bridges, the open ribs are less used because of their relatively lower torsional stiffness. However, with the design focus of OSD shifts from strength design to fatigue design, the system of open ribs shows the potential to be more considered for future projects. In this paper, a newly built OSD bridge is investigated focusing on the rib-to-crossbeam joint. Based on the in-situ measurements of the existing bridge, the numerical modeling of the whole bridge is finished. Furthermore, a simplified local model is developed focusing on the rib-to-crossbeam joint. Then, the influences of design parameters i.e. the crossbeam span and the spacing between ribs are investigated. Research results reveal that the global behavior of the bridge can be modeled. However, calculation results of points close to the connecting weld and the cope hole do not fit well with the measurements. In this case, increasing the crossbeam span will decrease the stresses of points close to the weld toe of the connecting weld. Increasing the spacing between ribs is more effective to reduce the tangent stress around the cope hole. The most unfavorable load position does not change with these two parameters.C

Updating of the corrosion degree based on visual data combined with strain or modal data

Many existing bridges are reaching the end of their technical service life. To estimate the remaining lifetime of reinforced concrete structures, it is important to assess the parameters of the corrosion process (i.e. parameters governing the corrosion propagation, but also parameters of the chloride or carbonation ingress). The level of corrosion and its spatial distribution can be inferred from strain data under static loading or modal data. In addition, information from visual inspections is often available as well, although not often used to quantify the level of corrosion. In this work, it is investigated how visual inspections can supplement the strain and/or modal data and provide information on corrosion parameters. The developed framework is applied to a simply supported beam subjected to corrosion.Many existing bridges are reaching the end of their technical service life. To estimate the remaining lifetime of reinforced concrete structures, it is important to assess the parameters of the corrosion process (i.e. parameters governing the corrosion propagation, but also parameters of the chloride or carbonation ingress). The level of corrosion and its spatial distribution can be inferred from strain data under static loading or modal data. In addition, information from visual inspections is often available as well, although not often used to quantify the level of corrosion. In this work, it is investigated how visual inspections can supplement the strain and/or modal data and provide information on corrosion parameters. The developed framework is applied to a simply supported beam subjected to corrosion.C