Experimental assessment of solar radiation effect on the stress-strain state of a span with an orthotropic slab

The article is devoted to the experimental assessment of the solar radiation effect on the stress-strain state of a span with an orthotropic slab. Preliminary, comprehensive instrumental measurements of the road surface temperature distribution and the span elements were carried out at different times of the year. A detailed picture of the temperature distribution over the cross-section height was determined at different air temperatures and the Sun positions. To assess the solar radiation effect, instrumental measurements of deflections and deformations of the span‘s main beams under the influence of solar radiation were carried out and the nature of the change in the stress-strain state of the span during the day was determined. The measurements were carried out using the deflection meters and strain gauges mounted on the main beams that experience uneven heating throughout the day. Using the developed and previously tested finite element model, the calculated values of the span bearing elements‘ stress-strain state parameters for each case of exposure to solar radiation have been determined, taking into account the experimentally obtained temperatures. Comparison of the calculation results obtained on the basis of field measurements and calculation in the program of the finite element method has been carried out. The most unfavorable cases of the solar radiation effect on the main beams‘ displacement have been revealed.