Rehabilitation of a deteriorating county-owned bridge deck in north-central Pennsylvania – an important artery for a popular amusement park and resort – eliminated bumpy rides for motorists in time for the busiest weekend of the year. The project eliminated certain structurally deficient concerns while preserving the balance of the structure to endure for many years to come.
The bridge carries employees and campers to and from the award-winning Knoebels Amusement Resort, America’s largest free-admission park since its founding in 1926. Family-owned and operated, Knoebels features an amusement park of some 60 rides, a picnic grove and campground. Its owners were concerned that construction might deter visitors and requested an escalated schedule for completion in time for the Fourth of July holiday weekend. The structure connects Cleveland Township in Columbia County with Ralpho Township in Northumberland County.
Larson Design Group served as design engineer and construction inspector on behalf of the bridge’s owner, Columbia County. Rather than utilize a reliable but more expensive half-width construction technique, LDG’s engineers designed a composite reinforced deck which takes advantage of the interaction between the concrete and the steel I-beams and increases the load carrying capacity of the bridge. Concrete curbs and bridge railings also were addressed and replaced as well as concrete end diaphragms and wing caps. To enhance public safety, the former pipe railing with no guide rail was replaced by a new bridge barrier and approach guide rail.
Grouted rock protection was built around the pier to prevent scour, the deterioration that occurs by the constant flow of moving water. The entire steel superstructure was blast cleaned and painted. The project also included improvements to the approach roadway and the installation of guide rail.
During the escalated construction schedule, LDG provided construction inspection and worked closely with the experienced contractor to complete the work on time and on budget. Among the obstacles overcome during construction were the bridge’s location on a popular shortcut to the amusement park which involved recreational vehicle motorists traveling on the closed road and turning around in the adjacent property owners’ yards. As well, one property was part of the Conservation Reserve Enhancement Program so access to the construction site was carefully constructed to avoid removing established trees.
Facts and Figures:
Structure Length = 77’ – 4”
Bridge Width = 20’ – 0”
Minimum Underclear = 6.1’
LDG Construction Cost Estimate = $460,507.18
Bid Spread = $457,476.27 to $467,031.30
As-Built Cost = $455,477.22