MONITORING HIGHWAY TRAFFIC OF LONG-SPAN BRIDGES BASED ON WIM DATA

The Tsing Ma Bridge in Hong Kong is a suspension bridge with a main span of 1,377 m. The bridge deck carries a dual three-lane highway on the upper level of the deck and two railway tracks and two carriageways on the lower level within the bridge deck. The highway traffic condition and the vehicle loading effect on the bridge have been closely monitored by a Wind and Structural Health Monitoring System (WASHMS) since 1997. By using the traffic data collected by weigh-in-motion (WIM) stations of the WASHMS, this paper analyzes the highway traffic condition and vehicle loading of the Tsing Ma Bridge in terms of vehicle traffic volume, vehicle traffic composition, axle load spectrum and gross vehicle weight spectrum. The measured axle load spectrum and gross vehicle weight spectrum are compared with the design spectrum.