Sibley Pond Bridge Replacement
UPDATED NOVEMBER 2011—Bridge Open to Public 10-1/2 Months Ahead of Schedule
The 10 span 790 ft long Sibley Pond Bridge with integral abutments and with only one expansion joint in the middle of the bridge was opened to traffic on November 21, 2011; before winter and approximately 10-1/2 months ahead of the MaineDOT’s scheduled project completion of October 2012. The bridge was designed and completed in 15 months.
The selection by the Lane Construction Corporation/Parsons Brinckerhoff Design-Build Team of the NEXT D beam (New England Extreme Tee) with its integral precast deck enabled the bridge to be erected very rapidly due to maximizing precast and limiting cast-in-place field concrete construction to continuity placements at the pier diaphragms and longitudinal joints between the beams. The project is the first to use the PCI New England NEXT D double T beam section and that too with self-consolidating concrete. The beams were cast by J.P. Carrara & Sons, Inc. at their Middlebury VT plant.
The beams were erected using a gantry crane running transversely on rails from the partly demolished existing bridge and across the new piers while Rt. 2 traffic was using a 2-lane temporary detour.
First NEXT “D” Project Underway in Maine
The Sibley Pond Bridge in Canaan-Pittsfield, Maine was built in 1939, after 72 years of service this concrete bridge is ready for its replacement to take over. Under the Maine Department of Transportation (MaineDOT) the new bridge would need to be cost effective with a minimum 100 year design life, low maintenance, and minimal impact to the traveling public.
In April 2010, the design-build team of The Lane Construction Corporation and Parsons Brinckerhoff (PB) submitted to MaineDOT the best value and lowest bid for the replacement of the existing Rt.2 Bridge that spans over Sibley Pond. In June 2010, the team received notice to proceed. The new 2 lane bridge is 36 ft curb to curb, 790 ft long (i.e. 10 - 79 ft spans), and straddles the Town lines between Canaan and Pittsfield, Maine. The bridge is comprised of two 5-span continuous units using the new PCI New England 36 inch deep NEXT D precast inverted T beam sections. The NEXT D beams with their full depth top slabs (unlike the NEXT F beams which require a cast-in-place topping slab) were selected by the design-build team for their economy, speed of erection, and since the deck is both precast and prestressed, for its potential to meet a 100 year life expectancy with minimal maintenance as specified by MaineDOT’s RFP.
The bridge spans over a shallow pond/peat bog with increasing thickness of organic soil deposits and depth to rock toward the middle of the bridge. As a result, fixity is provided at each semi-integral abutment supported on H piles driven to rock. Each intermediate pier is supported on a single row of 4 -2 ft. diameter concrete filled steel pipe piles which are designed to flex as “lollipop piers” as the bridge expands and contracts. There is a single expansion joint located in the middle of the bridge at the crown of the roadway vertical curve.
To date, several of the pile bents have been completed, and the first of the 10 ft wide NEXT D beam units were cast on May 4, 2011 by Carrara at their Middlebury, VT location. Traffic is due to be detoured this spring off the existing bridge to a temporary detour roadway. The 10 span bridge is scheduled to be erected and opened to traffic before the winter. Full depth cast-in-place concrete pier diaphragms will be provided at the piers and the longitudinal top slab continuity rebars that extend from the end of adjacent precast beams will be spliced using mechanical couplers. Transverse continuity will be achieved using 8 inch wide non-shrink high performance concrete closure pours, with interlocking headed stud anchors that protrude from the precast beam flanges. The deck will be protected from chlorides by a high performance waterproofing system and hot mix asphalt at variable depth to compensate for the beam cambers.
The precast concrete NEXT D beam is saving time and money while lowering maintenance needs, these attributes are beneficial to the economy while longevity ensures safe traveling for the public for the next 100 years.
Ground Breaking Date: 11-7-2010
Bridge Completion Date: 12-2011
Estimate Total Completion Date: 6-15-2012