Ellis County contracted with BG Consultants to evaluate and design repairs for bridge FAS 80, northwest of Ellis. The original structure was made of limestone piers and abutments supporting a concrete deck. After careful inspection, BG determined that only the deck needed replacement. The abutments and piers were still structurally sound with only minor limestone deterioration.
BG Consultants developed a plan to remove the concrete deck but leave the existing substructure intact. The pavement was cut at the back edge of the abutments, and all fill material was removed from the concrete deck. Once this was completed, the deck was saw-cut along the centerline of the piers, and each span was carefully lifted off the supports. The minor limestone deterioration was then cleaned and patched with a high strength concrete grout. A new 10-inch concrete slab deck was designed to match the existing road grade, with monolithic beams constructed to the top of the existing limestone piers and abutments.
Two major benefits were obtained through BG’s design. First, the dead load on the structure was lowered by removing the excess fill and driving surface on the deck, which in turn raised the live load capacity of the structure. Second, raising the top opening of the structure enabled more water to pass under the bridge in times of larger precipitation events. This solution successfully upgraded the original structure at a fraction of the cost of total bridge replacement.