Temperature monitoring of steel bridges

Abstract

The temperature monitoring of Tsing Ma Bridge is performed by the Wind and Structural Health Monitoring System on the Lantau Link as one of its functions. The system consists of over 90 platinum resistance type detectors on Tsing Ma Bridge installed at 4 selected cross-sections. Since May 1997, temperature measurements have been continuously recorded. The University of Hong Kong has been assisting in the analysis of these field measurements. This paper describes the instrumentation and data analysis related to the study. In parallel with this, experimental segmental steel sections under the influence of solar radiation have been set up on the university campus and temperature measurements have been recorded since 1993. Correlation results of observed data have shown that the temperature of steel sections mainly depends on the solar intensity and shade air temperature. Based on the theory of heat transfer, finite element models for different structural components of the bridge deck have been developed for prediction of temperature distribution. Good agreement with field data was observed. Comparison of positive temperature gradients among different structures has shown that they can generally be classified into two categories depending on the number of web faces exposed to the environment.