Dynamic performance of double-deck bridges under road vehicles and monorail trains

Abstract

With the development of transportation network gaining momentum as prompted by modernisation, the design of bridges as crucial components of the network has become more complicated not only in respect of the more challenging structural forms but also the increasing functions to serve. While safety is acknowledged to be the most important, there are many other criteria to address, including aesthetics, efficiency, reliability, riding comfort, etc. Bridges that carry mixed modes of traffic pose a new problem as different vehicles perform differently. This paper describes a framework for spatial dynamic analysis of double-deck bridges carrying both road vehicles and monorail trains taking into account road surface roughness and both vertical and lateral track irregularities. Both road vehicles and monorail trains are modelled as spatial mass-spring-damper systems while the bridge is modelled by finite elements. Then the governing equation of the whole interaction system can be assembled using a fully computerised approach and solved by direct integration. The dynamic performance of an authentic doubledeck long-span bridge carrying both road vehicles and monorail trains is investigated with special emphasis on the riding comfort of vehicles and trains.