Springborn Dam Bridge Pier Replacement

Fuss & O’Neill designed and permitted the removal of the Springborn Dam for the CTDEEP and performed construction inspection and administration. Structural services in support of this project included design of a scour wall to protect the mill building adjacent to the river and repairs to an existing CTDOT railroad bridge concrete pier in the Scantic River just upstream of the dam.

During construction, the river was dewatered and test pits were excavated alongside the bridge pier to confirm that the pier was founded on bedrock. The pier was observed to be in poor condition and was founded on timber cribbing above the bedrock. Since the riverbed was being dredged and lowered to bedrock, the timber cribbing would be left exposed to accelerated deterioration and decay. We developed and evaluated several options, after which CTDOT directed CTDEEP to design and replace the pier with a new concrete pier founded directly on bedrock. Our structural team designed a new railroad bridge pier and also developed and designed a method to temporarily support the bridge during demolition and construction. We collaborated closely with CTDOT Rails, CTDEEP, and the contractor to design and permit the new pier on an expedited basis within the original design and construction services budget.

The railroad bridge supports an active petroleum fuel pipeline that could not be moved more than ¾” vertically or horizontally. The temporary supports consisted of 40’ tall steel towers in the river on each side of the pier that were slid into place on temporary concrete pads.

The bridge was jacked 1/8” vertically to relieve the load and reconstruct the pier, then lowered back to its original position on the new pier, with no adverse effects on the pipeline or bridge.