Building a multi-span bridge over a major river is a challenging job. Many things are out of your control, key among them: the weather. That's why it normally takes close to two years to build such a structure. In spite of that, when the Missouri Department of Transportation asked for bids to construct a new bridge over the Meramec River in Arnold, Missouri, it stipulated that the work be completed in thirteen months.
The new Highway 61/67 Bridge is located about 50 feet downstream from the existing bridge. It is a nine-span, four-lane structure, with eight piers (four in the river) and two abutments. Undaunted by stringent time constraints, Goodwin Brothers Construction submitted their bid and was awarded the $11,950,000 contract. Work began August 1, 2003 and was completed in November 2004.
Meeting that grueling deadline required a sound plan of action, reliable equipment, and delivery of materials to the site in a timely manner. Goodwin Brothers, which specializes in water and sewage treatment plants, heavy concrete projects and bridgework, devised a plan. That plan included Hammer & Steel as a key supplier.
Knowing that it was essential to get the work out of the river before the spring rains hit, the contractor decided to run double shifts at the front end of the project. The object was to install the cofferdams, drive the H-bearing pile, and pour the concrete as quickly as possible. "We scheduled shift work for five months, just to stay on schedule," recalled Jay Goodwin, chief estimator for the firm.
Working several sections at a time, with up to three of the seven cofferdams installed at once, they raced to complete the pile driving. It was no easy task, setting as many as 192 piles in a single cofferdam.
Instead of using a diesel hammer with leads to install the bearing pile, Goodwin Brothers used a lightweight vibratory hammer (HPSI 130) to set the pile in the cofferdam and drive it part way, then used the diesel impact hammer (Delmag D19-42) to drive it to bearing capacity. The strategy turned out to be a great timesaving tool. "I would say that approach increased our labor efficiency rating on the H-pile by 25%," estimated Goodwin. In total, the company managed to drive 40,000 feet of new 12" X 53# H bearing piling by January 2004.
During the course of the job, Goodwin Brothers worked with Gary Talley, Hammer & Steel's territory manager, renting and then purchasing two vibratory hammers. "Hammer & Steel also provided a hammer on the job as a backup," Goodwin said. "That was important to us since we were working on such a tight deadline; it was critical that we not be slowed down by a possible equipment problem."
Goodwin took other steps to keep the project on schedule, as well. "We calculated some overtime to make up for rain and weather delays," he explained. "We had four cofferdams in the river - that's always a challenge. We knew we would be flooded out at some point."
That foresight provided a cushion so that when two unexpected floods hit before the spring, Goodwin Brothers was still able to stay on schedule. In fact, they were washed out three times-in December, January and March - when floods delayed the project by about a month.
Despite the best planning, there are frequently unforeseen problems, and this job was no exception. "When working with cofferdams, there are always surprises," Goodwin commented. "The problem is that you don't know what's under the riverbed, so while you are driving the pile, you run into an unexpected obstacle."
There can be challenges on shore, too. For example, Goodwin recalled, while driving sheet piling for one of the abutments, they ran into another bridge abutment. "It was probably from the original bridge across the river," he said. "It was too big to pull out, so we had to break it up."
The Highway 61/67 Bridge isn't Goodwin Brother's only fast-track project. Even as it was underway, the company was working about a mile down the river on the Lower Meramec Wastewater Treatment Plant project.
"That was even more crucial from a scheduling standpoint," Goodwin noted. "For that project, we drove 65,000 feet of 14" H pile in three months using two Delmag D30-32 diesel pile hammers rented from Hammer & Steel."
Having proven themselves on projects such as these, Goodwin Brothers is likely to see more of them in the future. "The state's goal is to limit any inconvenience to the public," Goodwin said. "We take these deadlines very seriously, and do whatever it takes to get the job done on time. We also know that we can count on Hammer & Steel to support us in these fast-track projects."
Products Supplied by Hammer & Steel