Narragansett, RI
Client: RIDOT
Construction Cost: $8.5M
Key Facts:
Originally constructed in 1959, Great Island Bridge No. 499 (top right) served as the sole means of access for the residential community of Great Island, spanning the tidal waters of Point Judith Pond between Bluff Hill Cove and the Port of Galilee. Due to its advanced age, condition, and substandard geometry, the RIDOT identified Great Island Bridge for full replacement.
The new bridge (completed in 2016) is a 3-span structure consisting of two, 57-foot end spans and an 86-foot center span, for a total length of 200 feet. The center span increases the clear channel opening from 25 feet to 76 feet. The cross section of the bridge is 48’-6” wide and provides for a 30-foot roadway, two 7’-6” reinforced concrete sidewalks, granite curbing, vehicular rail, pedestrian rail, and decorative lighting on both sides of the bridge, all supported by seven pre-stressed concrete box girders.
The substructure consists of two, short reinforced concrete abutments supported on micro-piles and two intermediate piers. The piers consist of reinforced concrete caps supported by steel H-piles driven to bedrock and caped by 30-inch diameter steel pipe pile jackets filled with concrete.
In order to maintain access to the island, a staged construction process was utilized. This process involved removing approximately half of the existing bridge while traffic was maintained on the remaining half. During construction, traffic was maintained using a one-lane, alternating-flow roadway regulated by temporary traffic signals. A portion of the new structure was constructed adjacent to the remaining section of the existing bridge. Upon completion of this portion, traffic was redirected onto the new structure while the remainder of the existing bridge was removed and construction was completed.
Final design and permitting were completed in 2014. The project was constructed at a cost of $8,538,000 between 2014 and 2016.
Awards:
2018 ACEC Engineering Excellence Award
Waterbury, CT
Client: CTDOT
Construction Cost: $157 Million
Key Facts:
GM2 is providing construction engineering and inspection services for this complex rehabilitation project; it entailed the construction of three temporary bridges, two over water and one over a local roadway; the conversion of a one-way road to a bi-directional road; and the rehabilitation of 10 bridges. The project involves complex maintenance and protection of traffic requirements including the construction of a temporary bypass roadway for Route 8 NB, the development of a U-turn roadway to accommodate highway traffic when interchange ramps are closed for rehabilitation and the selective use of temporary movable barrier to improve safety and facilitate bridge rehabilitation production during night time lane closures. Typical rehabilitation work involves both superstructure/substructure repairs and reconstruction. Common superstructure repairs include stripping the existing overlay, rehabilitation of the concrete bridge decks with partial and full depth patching, placement of new waterproofing membrane and overlay, steel repairs to mitigate corrosion and re-establish section loss, and bridge bearing/expansion joint replacement. Common substructure repairs include abutment/pier Class S Concrete patching.
North Haven, CT
Client: Town of North Haven
Construction Cost: $11.1 Million
Key Facts:
Project 100-175 involves reconstruction of Sackett Point Road and the replacement of State Bridge No. 03743 in North Haven, Connecticut. The roadway component of this work is approximately 1650 feet, east to west, and includes performing signal work at the intersection with Universal Drive, as well as adding roadway width and turning lanes. There are both overhead and buried utility relocations required, as well as new storm drainage being installed. The bridge replacement is in full, and is designed to occur in 3 phases over the course of 3 construction seasons. The existing two-span bridge is severely corroded and has reached the end of its service life, and will be replaced by a two-span integral abutment bridge founded on piles that is approximately 164’ long and that meets current geometric, load and service standards. There are a series of complexities to this project. The river, on average, has a 6-foot tidal swing and both ebb and floods with the tides each day, providing for very difficult construction and challenging environmental conditions. The site has abutters on each corner of the project, leading to more public information and public relations outreach, as well as staging of construction activities, materials and equipment. The road itself has a relatively high traffic volume (ADT) which resulted in the Town and State determining that closing the road to expedite construction was not feasible, nor was alternating traffic allowed, due to the volume of cars and backups that would result. This constraint led to the bridge being designed to be built in thirds, in 3 stages, resulting in a wider new bridge, while allowing for sidewalks and shoulders. Essentially, a new lane of bridge is built each construction year, working from north to south while replacing the in-service bridge as it progresses. There are buried utilities that are vital to the Town of North Haven under the river, immediately next to the bridge. These include a 20-inch water main and a 30-inch sewer main that flow in a "siphon" under the river. The construction of the new bridge is very close to these facilities, and they are to be closely inspected, monitored and protected throughout construction. The Contractor installed a series of survey prisms attached to sleeve rods that sit on top of the water main, as well as in the soil next to it, to hourly monitor if there are any shifts or settlement. The sewer main was stopped for a period pre-construction and a robot with a high-definition camera run through it, to check for any problems ahead of construction, as well as to record its condition before major activities. Finally, there are seismographs and sub-surface microphones installed in the soil around the bridge to monitor the pile and cofferdam driving activities and to ensure nearby structures are not compromised by this work. The tidal swing, the level of monitoring, and the barge-mounted work on the inner island during Stage 2 of construction are unique. This is also a newer bridge design philosophy, with integral abutments and wingwalls, and encased beam ends. There is also a complicated sequence of cofferdam installation in the river, working around the existing pier, as well as a tremie seal necessary to construction the pier footing, below the water level, in the dry.
Construction Inspection and Administration
Consultant Design Liaison
Construction Engineering (Temporary Work, Crane Placement, Heavy Lift Plans, Trestles, Rigging, Demolition Plans, Temporary Earth Retaining Systems)
Construction Survey and Layout
Traffic Management Plans
Detour Diversion Studies
Heavy Load Analysis
Temporary Signal Design
Permitting
Geotechnical and Subsurface Engineering, Temporary Support of Excavation
Instrumentation and Monitoring
Environmental Inspection
Drone Photography