InTrans / Aug 14, 2018

Field Performance of Timber Bridges: 14. Dean, Hibbsville, and Decatur Stress-Laminated Deck Bridges

The Dean, Hibbsville, and Decatur bridges were constructed in
southern Iowa during 1994. Each bridge is a simple-span, stress-laminated deck superstructure, approximately 7.3 m (24 ft) long, constructed from eastern cottonwood lumber. The performance of each bridge was monitored for approximately 2 years, beginning shortly after installation. Monitoring involved
collecting and evaluating data pertaining to the moisture content
and vertical creep of the wood decks, the force level of the stressing bars, and the behavior of the bridges under static load
conditions. In addition, comprehensive visual inspections were
conducted to assess the overall condition of the structure. Based on field evaluations, the bridges are performing well with minor serviceability deficiencies.