Load Ratings

Project Summary

Our Structures and Bridges Group recently completed load ratings for a dozen bridges in the City of Richmond. Each of the bridges has a unique aspect that was incorporated into the analysis. For example, one bridge has a steel girder bridge with an adjacent stairway and vehicle turn around area. Another bridge is comprised of a prestressed concrete girder bridge with cobblestone wearing surface and arched fascia girder. One bridge has a reinforced concrete arch structure with a larger utility opening in one wall. Our engineers developed models of each bridge using structural analysis software. The steel and prestressed concrete bridges were rated utilizing the VDOT approved AASHTOWare Bridge Rating software. The concrete arches were analyzed using the finite element software CANDE.

Any deficiencies impacting the structural capacity of the bridge were noted from the most recent inspection report and also modeled in the software programs. These programs analyze the structural model using multiple types of vehicular loadings to simulate real world loading conditions. These load ratings help identify structures that have insufficient load carrying capacity and may require posting, restricting some heavier weigh vehicles from crossing the structure.

The results obtained from the modeling were documented and summarized in a VDOT standard format, which was submitted to the City of Richmond along with supplemental hand calculations and notes compiled by our engineers. This work plays an essential role in keeping the traveling public safe and helping our public clients in prioritizing future infrastructure projects.