Dynamic interaction between vehicle and bridge deck subjected to support settlement

Many bridges inevitably experience foundation settlement during their lifetime. Structural engineers need to limit the foundation settlement so that the bridge structure does not develop intolerable stresses. One factor in the effect of foundation settlement on bridge structures that has not been considered so far is the dynamic interaction between bridge and moving vehicle. In this study, Hamilton principle is adopted to derive the governing equations for the vibration of line supported orthotropic thin plates due to moving vehicles. The effect of foundation settlement on the bridge–vehicle interaction (BVI) is investigated by modifying the interaction forces due to the deformed shape of deck. The effect of fully or partially developed membrane stresses on the BVI will be also discussed. The results show that dynamic load allowance (IM) increases depending on the support location where settlement occurs, mode of settlement, span length, and magnitude of the foundation settlement. However the effect of membrane stresses on IM is insignificant. The analysis results indicate importance of considering the effect of bridge support settlement on the dynamic BVI.