Finite element of multilayer surfacing systems on orthotropic steel bridges

Abstract

Light weight orthotropic steel bridge decks have been widely utilized for bridges in seismic zones, movable bridges and long span bridges. In the last three decades, severe problems were reported in relation to asphaltic surfacing materials on orthotropic steel deck bridges. Earlier investigations have shown that the bonding strength of membrane layers to the surrounding materials has a strong influence on the structural response of orthotropic steel bridge decks. The most important requirement for the application of membrane materials on orthotropic steel bridge decks is that the membrane adhesive layer shall be able to provide sufficient bond to the surrounding materials. The research aims on developing a FE tool to simulate and understand the performance of asphaltic surfacing structures, so as to improve the design of surfacings and increase their service life. In this paper, Finite Element (FE) simulations of Merwedebrug bridge with two membrane layers system are presented. The finite element system CAPA-3D developed at the Section of Structural Mechanics of TU Delft has been utilized as the numerical platform for this study. Due to the multilayer of the surfacing materials and geometrical complexity of the steel bridge, the FE model shows the in time development of strains and stresses inside the surfacing materials depends highly on the wheel loading frequency, wheel position, membrane bonding strength as well as thicknesses and characteristics of the surfacing layers. Emphasis is placed on the distribution of strains and the evolution of damage in surfacing layers of different cases. Recommendations of surfacing structures design on orthotropic steel bridges are given.