Day by day, the old Washington Convention Center is steadily disappearing from its site in Washington, D.C. Since the implosion of the building on Dec. 18, 2004, crews have been working to complete the demolition.
The prime demolition contractor for the job is Wrecking Corporation of America, Washington, D.C. The company is working with Goel Construction Services, which has a contract with the Convention Center Authority for approximately $6 million. Funding is provided by the D.C. government.
“This is a landmark project for the Washington, D.C. area for a number of reasons,” said Terry Anderson, executive vice president and chief operation officer of Wrecking Corporation.
“One, is it’s probably the largest single building under roof that has been taken down in the area in a long time. We have done many large high-rise buildings in Washington, but none of them rivaled this one. The whole site is about nine city blocks, so the building itself is a footprint of about 400,000 square feet, and it’s two levels, so it’s about 800,000 square feet under roof. That makes it massive when you go in there, because it’s only two levels, so it’s cavernous when you walk in and look from one wall to the next.”
Anderson noted that the demolition was necessary because a new Convention Center is in use several blocks away, and the old one was sitting on valuable land and costing money as well.
“They decided that they were going to go out and redevelop the site,” he said, “and they had picked a development team to go out and come up with a design-build project, which is going to probably take about two or three years to break ground on. In the interim, they decided that they needed more parking, so when we get done with the demolition project, they will then build a temporary parking lot on that site to facilitate the conventions they’re having at the new convention center.”
According to Anderson, notice to proceed with the project was given on Aug. 2, 2004, and the first two months were spent “chasing permits, doing cutting and capping of utilities, and haz-mat abatement.”
The raze permit was obtained in October, and the next two months were spent on selective demolition and structural demolition to prepare the structure for implosion. Currently, work involves removing structural steel, and the next phase will involve concrete removal and processing. The entire project is expected to be complete by the beginning of July.
One of the main challenges for the project involved the landmark status.
“They have not imploded a structure in the downtown D.C. metro area in about 30 years,” said Anderson, “so in order to get the permits and to get all the approvals that were required, it took endless meetings for community relations for security and the planning and to get the traffic control plan. We had to meet with many city agencies as well as many federal agencies, because many of those federal agencies are the neighbors that surround the site. It certainly took awhile to get everybody comfortable with the fact that, in a post-9/11 world, we were going to come in and bring explosives into downtown D.C. and implode a structure.
“We had people like Homeland Security, the Secret Service, the U.S. Mint, the Treasury Department, the Smithsonian, and two major hotels directly across the street from the project. But we were able to certainly meet the challenge and overcome the obstacles and get all the permits — certainly much to the credit of our client and to the credit of the D.C. fire department and police department — which were very supportive in the process, and ultimately had the authority and were the last ones to give us the permit to bring the process to fruition.”
In the end, Anderson noted that the implosion went very well.
Two types of explosives were used. “One was linear-shaped, like an RDX explosive, which is a very high velocity explosive that’s used to cut steel,” he explained.
“Because there was a concrete component to the building, we used a high-velocity nitroglycerine-based product for that. There were over 400 different delays in a 12-second sequence, and the whole implosion maybe lasted somewhere between 15 and 20 seconds from the time the explosives went off and the building actually failed and came to rest.”
The goal was to drop the steel structure down to a level where it could be reached with large excavators and sheers.
Wrecking Corporation has remained on schedule with removing debris, and the next step will be to recycle all of the concrete and masonry on the site. According to Anderson, approximately 50,000 yds. (45,720 m) of materials will be crushed to a 4-in. minus, then the product will be graded out on site to become the sub grade for the planned temporary parking lot.
Although Wrecking Corporation is doing most of the work themselves, Anderson noted that they did bring in one implosion contractor for the explosives work. This job was handled by Demolition Dynamics, Franklin, TN.
“For the cleanup phase,” Anderson said, “we’ve been working with J.W. Burress, and they supply Hitachi excavators. We have a fleet of Hitachi excavators out there right now.”
The list includes a 600 Hitachi Zaxis, equipped with a rotating LaBounty shear, an MSD 100R, three 450 Hitachi Zaxis machines — one with an HDR grapple, one with a CP100 concrete pulverizer, and the third with an MSD70R; three 330 Zaxis machines, equipped with pulverizers, buckets and thumbs for sorting and loading material; a 270 with a bucket and thumb; and several demolition hammers including a Gradall 5200 with a 5,000 ft.-lb. hammer; a Liebherr 932 excavator with a 5,000 ft.-lb. hammer, a 90-ton (81.6 t) truck crane, a fleet of Melroe Bobcats and several skid steers.
Anderson noted that approximately 10,000 gross tons (9,072 t) of steel will be recycled, which includes everything from structural steel to rebar to miscellaneous light metals. Approximately 350,000 lbs. (158,757 kg) of non-ferrous scrape was removed from the site prior to the actual implosion.
Approximately 50,000 yds. of concrete and masonry will be recycled, and approximately 400 dumpster loads were hauled off for disposal. According to Anderson, 95 percent of the structure will be recycled.
“Everybody’s very happy with the process,” Anderson said. “We’re very happy with the aftermath, which is the cleanup. The city has been incredibly cooperative in giving us what we needed to do it, even though it took many, many meetings and many, many submittals, so we’re very happy with where we are.”
Groundbreaking for the old convention center took place in 1980, and the building opened in 1983. It was the fourth largest convention center in the United States with 800,000 gross sq. ft. (74,322 sq m) and 350,000 sq. ft. (32,516 sq m) of exhibit space. The building housed more than 1,500 major conventions in its time.
Before the implosion, Mayor Anthony A. Williams said, “The former convention center marked the beginning of an economic revival in the District. It will always be remembered for its impact in Washington. As this building comes down, we look forward to creating a new city center with expanded opportunities for housing, retail, restaurants and inviting public spaces. I’m eager to explore the tremendous potential presented by this site.”