I-81 Buffalo Creek and Maury River Bridges. Rockbridge County, VA.
Buffalo Creek was awarded VDOT Virginia Statewide Construction Quality Award, NPHQ Award “Breaking The Mold” and ACEC Grand Award For Design Excellence. Maury River received the ACEC Grand Award For Design Excellence
Interstate 81 projects were the beginning of VDOT’s efforts to widen the interstate through Virginia. The Buffalo Creek Bridge Replacement project was selected as one of the first due to the steep grades approaching the bridge and high crash rates and was designed to provide for truck climbing lanes to improve safety and traffic operations along the 81 corridor. Both bridge replacement projects include total replacement of the aging bridges and reconstruction of one mile of approaches. Projects also widen the interstate from four lanes to six lanes through the limits of the projects. Projects are located in karst terrain requiring extensive geotechnical evaluation for bridge foundation and large roadway cuts and embankments.
The project included widening of over two miles of the interstate 81 from four to six lanes. The design required total replacement of the existing pavement section requiring shifting the alignment to allow for maintenance of traffic during construction.
The projects required a detailed hydraulic analysis of both Buffalo Creek and Maury River to ensure the project had no impact to the 100-year flood elevation. The analysis included the evaluation of bridge scour and the construction of temporary causeways in the stream.
Complex geotechnical investigation and analysis was completed for the bridges and roadway approaches for the project located in karst terrain. At the Buffalo Creek Bridge a underground stream feature was identified in the existing median requiring the shifting of the northbound lanes to the east.
Buffalo Creek Bridge consisted of continuous hybrid steel plate girder bridges (NBL Bridge of 606’ and the SBL Bridge of 584’). Both bridges required tall piers of up to 110’ in height. Maury River Bridge NBL bridge is 825’ and the SBL bridge is 743’.
Buffalo Creek NB bridge was constructed in two phases, while the southbound bridge was shifted into the median and constructed in a single phase. Maury River Bridges were replaced by constructing the new northbound bridge to the east and shifting northbound traffic onto the new structure while the southbound bridge was replaced.