Building Bridges to a Better Infrastructure
Building Bridges to a Better InfrastructureWashington D.C.’s 11th Street Bridge Project critical to improving travel between freeway systems
Located in southeastern Washington D.C., the $390 million 11th Street Bridge Project is the largest project underway in the District Department of Transportation’s (DDOT) Anacostia Waterfront Initiative, which consists of two phases and involves the re-creation of the transportation infrastructure network to promote safe, efficient, multi-modal travel throughout the Anacostia Waterfront area. Two Putzmeister 47Z-Meter Truck-Mounted Concrete Boom Pumps, one Putzmeister 36Z-Meter Truck-Mounted Concrete Boom Pump, one 20Z-Meter Truck-Mounted Concrete Boom Pump, and one Telebelt® TB 110 Telescopic Belt Conveyor have been placing concrete and stone on the project.
Phase I: 20 Bridges
Phase I of the 11th Street Bridge Project began in late 2009, was completed in spring 2013, and included the construction of 20 bridges to provide direct connections between the Southeast-Southwest Freeway and both directions of Interstate/DC-295, fixing a long-standing deficiency that forced motorists to use local streets to connect to and from both freeways. The project’s joint general contractors, Skanska USA Civil SE and Facchina Construction Company (Skanska Facchina JV), hired Maryland-based Aaron’s Concrete Pumping, Inc. (Aaron’s), the only woman owned concrete pumping company in the Mid-Atlantic region that is certified with various state and county minority divisions, for material placement.
The team at Aaron’s used its Telebelt® TB 110 belt conveyor at the bridge abutments to place approximately 20,000 tons of stone, in addition to dirt, as wall fill for the mechanically stabilized earth (MSE), which consists of a precast concrete panel stacked vertically and held in place with both galvanized reinforced strips and backfill material containing specific engineered properties.
The stone and dirt is contained by the MSE wall panels on all four sides, which didn’t allow for access. This required Skanska Facchina JV to convey the material up over the walls to speed the process in constructing these abutments.
“For the approach ramps, with no access for dump trucks, using a Telebelt to move the material was much faster than the traditional crane and bucket or excavator methods,” explained Joshua Sheets, vice president and co-owner of Aaron’s. “It saved the crew a lot of time and headache.”
Phase II: Three Additional Bridges
The second phase, which began in early 2013, includes the construction of three additional bridges to further improve freeway connections. The project is replacing two bridges built in the 1960s with new bridges that separate local and freeway traffic.
Aaron’s was also hired to work on the second phase of the project. Two Putzmeister 47Z-Meter Truck-Mounted Concrete Boom Pumps, one Putzmeister 36Z-Meter Truck-Mounted Concrete Boom Pump, and one 20Z-Meter Truck-Mounted Concrete Boom Pump will pump the approximately 8,000 yds3 (6,116m3) of concrete for the bridges. The TB 110 will be utilized for the bridge abutments on Phase II, as well.
Pumping for Good
Tracey Sheets Rhoten, president and CEO of Aaron’s, recently had Putzmeister outfit one of her company’s two 47Z-Meter trucks on the 11th Street Bridge Project with a special decal supporting Autism Speaks, a leading autism science and advocacy organization. Aaron’s has committed to donating one percent of sales from the truck every year to Autism Speaks to help raise awareness for the disorder.
As a parent of a child with Asperger’s syndrome, an autism spectrum disorder, the organization is close to Rhoten’s heart.
“One in 88 children are affected by autism,” she explained. “Many schools are cutting funding for kids with special needs, so any support we can give to organization like Autism Speaks can really make a difference in their lives.”
Rhoten said the response to the truck and her company’s commitment to Autism Speaks has been overwhelmingly positive.
“It’s amazing how many people on our jobs have children, nieces and nephews, and friends whose children struggle with autism,” she said. “We’ve had so many generous customers, vendors and employees willing to donate money under my son’s name. It’s been really touching.”
Large Pours in Close Quarters
The ‘Autism Speaks’ truck, along with the second 47Z-Meter, the 36Z-Meter and the Telebelt, are restricted to limited space on the 11th Street Bridge Project, due to several factors. The freeway location has proved challenging, limiting the amount of working room for equipment. There are also cranes and other heavy construction equipment and materials on site, which allow for less space for the pumping equipment. Thus, the compact footprint—with outrigger spread of 26 feet, 1 inch (7.95m) in the front and 29 feet, six inches (8.99m) in the rear—of the 47Zs and the 36Z—with outrigger spread of 20 feet, 7 inches (6.27m) in the front at 21 feet, 8 inches (6.60m) in the rear—has been beneficial.
Another setup challenge is the fact that there is a railroad track and tunnel that runs underneath the site. The equipment has to be strategically placed below the bridge cap, but above the train tracks, leaving little room for error.
“With so many limitations in the working area, we needed equipment to be flexible and easy to move,” said Sheets. “The compact footprint of the Putzmeister equipment worked out perfectly on this job site.”
The 47Z’s maneuverable five-section boom, with a reach of 151 feet, 3 inches (46.10m) vertical and 138 feet, 1 inch (42.09m) horizontal, also helped the efficiency and ease of the concrete placement. The five-sections provided the necessary maneuverability to get over and down into the form work.
“Without having a lot of room to work with on the job site, having trucks with a long reach and lots of flexibility was essential,” Sheets added.
While the working area is small, the pours are fairly large for this type of project. The substructure components, piers, columns and caps being poured for the bridges are massive and tall, making consistent concrete placement critical.
“The Putzmeister equipment handled the pours with accuracy and ease,” said Sheets.
In addition to the work the 47Z-Meters and the 36Z-Meter have been doing on site, Aaron’s also used its 20Z-Meter Truck-Mounted Concrete Boom Pump to work on the substructure for two of the bridges. The 20Z-Meter was set up on top of the bridge deck and the pump placed concrete for a 120-foot deep by 20-foot in diameter substructure shaft, replacing the typical footing column and caps.
“The 20Z-Meter worked perfectly in the location on the bridge deck, as its reduced footprint allowed us to only shut down one lane of traffic,” Sheets explained.
Beating the Traffic
Since the purpose of the 11th Street Bridge Project is to help improve traffic flow on the city’s overcrowded freeways, it was inevitable that controlling traffic during construction would be a challenge.
“The daily volume of traffic in the DC metro area is huge,” explained Rhoten. “Every possible scenario was discussed to develop the best schedule for placing concrete.”
Ultimately, the crew decided to begin concrete placement for each of the nine pours needed for each of the three bridges around 3:00 a.m. to take advantage of the lighter traffic at that time. Given the efficiency of the crew and equipment, the first of the 440 yd3-pours (336m3) were completed in just eight hours without any problems.
“The quick setup and removal of the 47Zs has been especially beneficial on this job site, as we are doing everything we can to minimize the disruption of traffic,” added Rhoten.
A Smoother Ride
The majority of the work on the 11th Street Bridge Project will be completed by the end of 2013, with the finishing details to be wrapped up in 2015.
Overall, the 11th Street Bridge Project will improve vehicle travel throughout the metro D.C. area, providing faster free-moving traffic patterns, eliminating traffic congestion, along with adding new storm drainage and other environmental investments to treat all storm water within the project area, and a 14-foot-wide pedestrian and bicycle path on the local bridge that connects with the Anacostia Riverwalk Trail.
Owner/Developer: District Department of Transportation – Washington, D.C.
General Contractor: Skanska USA Civil SE – New York, N.Y; Facchina Construction Company – La Plata, Md.
Equipment Owner: Aaron’s Concrete Pumping, Inc. – Eldersburg, Md.
Ready Mix Concrete Provider: Aggregate Industries – Waltham, Mass.
Equipment: Two Putzmeister 47Z-Meter Truck-Mounted Concrete Boom Pumps, one Putzmeister 36Z-Meter Truck-Mounted Concrete Boom Pump, one 20Z-Meter Truck-Mounted Concrete Boom Pump, and one Telebelt® TB 110 Telescopic Belt Conveyor.