Indian River Inlet Bridge Test Pile Driving To Occur Later This Month
The Department of Transportation (DelDOT) announces that Skanska USA Civil Southeast, the design-build contractor for the new Indian River Inlet Bridge, is on the construction site and is mobilizing manpower and equipment for the first major construction activity. The first activity will be the driving of two 24-inch square, 140 feet long prestressed concrete indicator piles. The piles are scheduled to be driven during the latter part of November.
These test piles will provide valuable geotechnical information that will be used to ensure that future piles perform as intended. Both indicator piles will be driven on the south side of the inlet. Area residents and visitors can expect some noise during daytime hours as the piles are driven. The pile driving operations will be monitored via seismic testing by Skanksa. The pile driving operation will not require any traffic restrictions for motorists or cyclists, and will not impact boaters or fisherman in the area.
After the indicator pile geotechnical information is compiled and analyzed, off-site production of the bridge's 36" x 36" prestressed concrete piles will commence. Delivery and installation of the larger piles to be used in the actual bridge construction is expected to occur early in 2009.
Beginning this winter, there will be varied opportunities for public input and participation into the bridge building project: specifically, the public will have input into determining some architectural and visual features of the new bridge, including the color of the cable stays, the design of the pylon tops, and the pylon picnic area form linear details.
As construction progresses, DelDOT and Skanska will offer other educational outreach activities. More information will be provided in the future on these public opportunities.
Skanska Southeast was awarded the $150 million-design build contract in August 2008. Of the three proposals received, Skanska had the lowest price, highest technical score and the shortest construction time.
The new design is dynamic and functional. It will have two 240 feet high towers/pylons on each side of the bridge with single plane cable stays. For comparison, Williams V. Roth Jr. Bridge over the Chesapeake & Delaware Canal has two towers/pylons approximately 180 feet tall and a single plane of cable stays down the center of the bridge. The current Indian River Inlet Bridge has support piers in the inlet and no supporting towers.
The new bridge will also be 2,600 feet long, including a 900 feet clear span over the Inlet, with 1,700 feet of bridge over land. All supports will be out of the water, eliminating the conditions that now exist with the existing bridge. The new bridge will have a minimum 100-year design life. The foundations will be supported on 36 inch-square piles which will be manufactured by Bayshore Concrete Products, a subsidiary of Skanska Southeast. Skanska had previously used these types of piles on the Escambia Bay I-10 Bridges in Florida.
Under the new design, the minimum vertical clearance will increase from the existing 35 feet to 45 feet over the navigational portion of the inlet. The bridge will have two 12 feet wide travel lanes, a 10 feet wide outside shoulder, and a 4 feet wide inside shoulder in each direction. Additionally, one 12-foot wide sidewalk will be accessed from the east side of the bridge. The reduced embankment limits will result in the elimination of massive embankments and will provide an open view.
Skanska Southeast has earned a reputable reputation as a builder of some of the most noteworthy construction projects in the Southeastern United States, including the Cooper River Bridge in South Carolina and the Woodrow Wilson Bridge Foundations in Maryland.
The following bridge monitoring is taking place to ensure the existing Indian River Inlet Bridge remains safe while the new bridge is being constructed:
-Yearly visual inspections: The last inspection took place in August 2008, and nothing of concern was found.
-Underwater Dive Inspections: The most recent inspection occurred in October 2008 and no changes in the scour condition near the piers nor in the general area were noted.
-Bathymetric Surveys: DelDOT conducts annual bathymetric surveys, and additional surveys after severe storm events. In addition the Army Corps of Engineers has continued to provide DelDOT with their periodic bathymetric surveys. These pictures are posted on www.irib.deldot.gov.
-Land Survey Equipment: Land survey equipment is used to monitor movement, if any occurs, on the existing bridge on a regular basis (monthly).
-Sonar monitoring device: DelDOT is working with the University of Delaware to install sonar devices on the bridge to further monitor the scour progression.
-Pier Sensors: DelDOT worked with the University of Delaware to install pier sensors on the bridge.
All monitoring devices indicate that the existing bridge is structurally sound and safe for the traveling public's use.
The current bridge will remain in place while the new bridge is built. After construction of the new bridge is complete, the old bridge will be demolished. DelDOT is currently discussing options for disposal with the Army Corp of Engineers.
For additional information on the history of the bridge and project including renderings of the new bridge go to www.irib.deldot.gov. This Web site will be updated periodically, so visit the site often for the latest information on the building of the new Indian River Inlet Bridge.