InTrans / Aug 14, 2018

Field investigations of stress-laminated T-beam and box-beam timber bridges

Field investigations of selected stress-laminated T-beam
and box-beam bridges in West Virginia showed that several bridges had cracks in their asphalt wearing surfaces at the web-to-flange interface and lower than expected levels of stressing bar forces and interlaminar compressivestresses. This indicated possible slip between webs and flanges resulting in lack of full composite action and levels of structural safety lower than whatwas assumed by the designers. While the bridges continue to carry vehicle traffic, the inspection program found several areas of concern that will affect their long-term ability to safely carry vehicle loads in a cost-effective manner.