McMahon & Mann designed temporary footings to support two cranes that Oakgrove Construction, Inc. used during the Campbell Boulevard bridge demolition over Tonawanda Creek. The footing design considered the weight of the cranes, the weight of the bridge truss and the various crane positions that Oakgrove would use when lifting the truss. The position of the crane on the creek bank was determined by the crane’s lifting capacity and placed the footings at the top of the banks.

McMahon & Mann used subsurface information from the site and the site topography to estimate the allowable soil bearing pressure to size the footings. The history of bank instability along Tonawanda Creek was also considered in the design.

Oakgrove safely lifted the truss, placed one end of the truss on one of the creeks banks and the other end on a barge floating in the creek. We observed the response of the footings during the lift and found that the footings did not noticeably move, confirming the adequacy of the estimated ground properties. Once on the ground and the barge, Oakgrove completed the truss demolition.