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Bridge Shoring

Barnhart was hired by a nuclear client in California to come up with a solution to move a Reactor Pressure Vessel (RPV) from a decommissioned nuclear plant. The RPV weighed 1,365,000 pounds and needed to be transported via railroad out of Southern California. However, extensive railroad bridge analysis of the route found that the triple span bridge over San Juan Creek would be overstressed when the RPV traveled over it. Barnhart was enlisted to help solve the problem.

Barnhart’s engineering team developed a solution using the Barnhart pull-up gantries, which also included a steel and wood crane matting to minimize the ground bearing so that it would not exceed the 2,700 psf site requirements. A custom header beam had to be designed and fabricated to allow two gantries to equally share the load while having proper bearing on the riveted support girder.

The biggest challenge on the project was that the creek bed had continuous flowing water when it was time to shore the bridge. In order to manage the water, Barnhart built a temporary creek diversion to divert the water around the gantry shoring at each span. Barnhart also performed site grading to allow for access in the creek bed and to establish a level, compacted surface for the setup of the gantries.

In the end, the RPV traveled safely over the structure as the pull-up gantries worked as planned to assure the bridge maintained structural integrity. The creek bed was returned to its previous water flow, satisfying all environmental concerns. The job was completed on schedule without incident.