“Effect of Temperature Stresses in Composite Girder Bridges”

International Journal of Research and Scientific Innovation (IJRSI) | Volume V, Issue VIII, August 2018 | ISSN 2321–2705

“Effect of Temperature Stresses in Composite Girder Bridges”

Vishnu Sharma*, Dr A. K. Dwivedi**

 *Research Scholar in Rajasthan Technical University Kota, Rajasthan, India
** Professor in Civil Engineering Department, Rajasthan Technical University, Kota, Rajasthan, India

Abstract: – Thermal actions differ from other load types considered during bridge design through being a constraining load. A temperature profile can be divided into a uniform part that affect the bridge with a linear expansion and a non-uniform part that will induce an arch shape of the bridge deck.
The response of composite bridge structures to environmental temperature effects is a complex transient phenomenon as bridges are subjected to daily repeated cycles of solar heating and cooling and ambient temperatures varying with time.
Composite bridges exposed to environment continuously undergo varying temperatures due to diurnal and seasonal changes in climatic or atmospheric conditions. Temperature distributions in a bridge structure depend upon several environments, meteorological and a bridge parameter. The major environmental parameters influencing the temperature distributions in a bridge structure include intensity of solar radiation, daily range of ambient air temperature humidity, cloud covers, wind speed, turbidity of atmosphere etc.
In addition to these parameters the temperature variation in bridges is also affected by some other parameters as well which includes geographic location of the bridge as governed by the latitude and altitude, geometrical parameters and materials properties of the bridge cross sections.
Diurnal and seasonal changes in the local climatic conditions cause the rise and fall in the overall temperature of a bridge structure, referred to as effective bridge temperature, and development of temperature differentials across the depth of cross section referred to as thermal gradient or differential temperature. The range of the daily maximum and minimum ambient air temperature usually affects the effective temperature of the bridge while the solar radiation contributes to the thermal gradients in the bridge cross sections.
The objective of the study were to construct and instrument composite bridge, b) to subject the structure to thermal loading, and c ) to correlate the experimental temperature distributions. It was concluded that theoretical procedure provides a rational method for predicting the thermal behavior of composite-girder bridge structures and can be applied with reasonable confidence when used with realistic temperature, profiles, material properties, and substructure stiffness characteristics.

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