The relocation project of I-195 in Providence, RI, has created a domino effect there. To move the intersection of that highway and Interstate 95, numerous other huge construction projects must be undertaken first.
Take, for example, the 1,250-ft. (379 m) bridge that carries I-195 across the Providence River. Work is just beginning on a new one, 2,000 ft. (606.7 m) to the south. It is all a part of the plan to move the intersection of the two interstates, thus making I-195 a straighter and safer route for travel through the city.
However, such a plan is easier said than done. A total of 15 new bridges in Providence will be constructed, along with numerous ramps and a 50-ft. wide (15.2 m) pedestrian bridge.
The Providence River bridge, which was designed by Maguire Group of Foxboro, MA, is expected to be the crowning achievement of the entire project. Its three-part design, including a “network arch,” with tub and box beam sections on either end is unique. The network arch section will measure approximately 400 ft. (121 m) long and 120 ft. (36.4 m) above the river. At 155 ft. (47 m) wide, it will accommodate eight lanes of traffic on the busy highway.
“This new signature bridge over the Providence River will help to redefine the city’s skyline in a way that is architecturally interesting and unique,” said Richard J. Repeta, president and CEO of Maguire Group.
The bridge not only will be functional, but the design also will make it a centerpiece of the relocation project. Two 10- by 14-ft. (3 by 4.2 m) masonry pylons will rise 30 ft. (9.1 m) above the bridge deck. They will be lighted at night, so they will take on double duty as lanterns for the city. It also will be covered with a brick veneer to add a sophisticated look.
“It’s not only a structure, it will be something to look at,” said project manager Tony Almeida.
The intersecting hangars for the bridge will be inclined to utilize truss action. It is known as a Nielson-Lohse bridge and will have smaller bending moments in the arches and tie girders. Boats will pass underneath the span into the inner harbor of Narragansett Bay.
Construction on the $85-million project started in mid-August. According to Almeida, things began slowly by relocating local utility lines and pouring concrete footings for the hurricane gates (scheduled to be built with sheet piling) and removing rock facing from a dike along the river.
After that, attention will be directed to a wall next to the highway. Footings will then be poured for the land piers, Almeida continued. Work is expected to continue through 2007.
One advantage of the project is that throughout the duration of the work no traffic will be affected. In turn, no traffic will affect it. It is a brand new bridge in a new location so no connections will be made with the highway until everything else is entirely finished. In fact, that part of the work will be done under the auspices of a different contract to be signed at a later date.
“It is a virgin job in the middle of the city of Providence,” said Steve Cardi Jr., of Cardi Corporation in Warwick, RI, the primary contractor for the job. Cardi will use standard equipment throughout the work, such as Caterpillar 345 backhoes and Link-Belt 100-ton (90 t) cranes.
One of the subcontractors, though, Raito of Japan and San Leandro, CA, will install piles with an unusual machine. Instead of driving the piles into the ground, Raito will screw them in like a screwdriver through obstructions and boulders. That way, the work will be more efficient and workers will have more vertical control. Workers will drill the 8-ft. (2.42 m) diameter shafts, which will go down 80 to120 ft. (24.2 to 36.4 m) and 11 to 30 ft. (3.3 to 9.1 m) into the rock. That still comes up short on the Raito company record — workers once drilled a 5 ft. (1.5 m) pile 234 ft. (71 m) down into the ground.
The method is known as “supertop” and piles as large as 10 ft. (3.03 m) in diameter can be drilled with the process.
Almeida said he doesn’t expect the bridge to include a lot of excavation. Only 60,000 to 70,000 cu. yds. (45,600 to 53,200 cu m) of fill will be produced along with 45,000 to 50,000 cu. yds. (34,200 to 38,000 cu m) of construction excavation. Most of the work, he said, will be done on the superstructure well above the water.
When I-195 was first built back in the late 1950s, the Interstate system throughout the country was still new. Although it has always been an important access to Providence from the east, it was not a well-planned route. It wound through the city and split neighborhoods with little forethought given to its impact. Initial plans expected the highway to carry no more than 75,000 vehicles a day, but that number has ballooned to 180,000 since then. Subsequently, traffic jams are common in both directions.
The direct alignment will let speed limits be increased from 40 mph to 55 mph. All exits have been placed on the right side, so traffic will no longer have to weave to exit (some cars currently have to exit on the left). Distances between on and off ramps will also increase. In the process, 30 buildings will be demolished.
All other facets of the relocation project will be finished in 2004.