Bridge Load Test and Load Rating of Reinforced-Concrete Slab Bridges

The safe load capacity of a bridge structure is generally determined from bridge load-rating calculation. Several methods, namely allowable stress method, load factor method, and load and resistance factor rating (LRFR) method, are currently used for this calculation. A large number of old bridge structures were however evaluated using the allowable and load factor methods. A comparative study of the load rating factors given by these methods was conducted to provide an insight to how load ratings previously determined for old reinforced concrete bridges would change when calculated by the recently developed LRFR procedure. Based upon the load rating results of eleven existing reinforced concrete slab bridges with various span lengths, the allowable stress method was found to provide the most conservative estimates of the safe load capacity due to relatively low member resistances given by the method. The LRFR ratings were slightly greater than the load factor ratings at the inventory level but tended to be lower at the operating level. Additionally, one of the bridge structures was selected for nondestructive load test. The experimental and analytical results indicated that edge elements provided additional stiffness to the bridge structure and significantly increased load distribution efficiency. The LRFR method for calculating equivalent width was found to considerably overestimate the live load effects. A significant increase in the rating factor could therefore be obtained from the nondestructive load test.


  • English

Media Info

  • Media Type: DVD
  • Features: Figures; Photos; References; Tables;
  • Pagination: 16p
  • Monograph Title: TRB 89th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

Filing Info

  • Accession Number: 01151032
  • Record Type: Publication
  • Report/Paper Numbers: 10-3002
  • Files: TRIS, TRB
  • Created Date: Jan 25 2010 11:28AM