LeJeune Steel Co. has manufactured so many structural steel components in Minneapolis that it can almost be said that the company built the Minneapolis skyline. Getty Images.
If you want to build royal buildings for towering stadiums, deep underground caves of epic proportions, and bridges that span the widest river in the world, you’d better be equipped with sophisticated equipment.
Structural steel manufacturer LeJeune Steel Co. competed and won awards for the country’s largest and most complex structural work. “We like to specialize in large and complex projects,” said Josh Barten, vice president of operations.
The company’s website showcases its fabricated sports, entertainment, medical and university construction projects, including the Bank of America Stadium, a large underground auditorium project for a large software company in Wisconsin, the Washington Avenue Bridge across the mighty Mississippi River, and Ming The entire skyline of Niapolis.
Obtaining those monumental display items depends on whether they can meet the speed, accuracy and repeatability requirements.
The management of LeJeune Steel decided in 2008 that if it is to keep up and hope to meet the customer’s quantity and output requirements in the future, it is indeed necessary to automate manufacturing equipment and processes.
“Due to advances in design, the types of work we feel we are good at, that is, larger and more complex jobs, have become more complex. New 3D design software like Tekla and SDS/2 enables architects and engineers to design more More complex buildings with complex connections. When we make them by hand, use manual layouts, magnetic drills, and try to flame-cut upper covers and slopes with a flashlight, our ability to make and keep up with these new designs is really limited.”
”We realized that if we want to continue to stand out in increasingly complex jobs, we need automation and CNC equipment that can take these very detailed 3D files and put them into programs that can make machines run automatically. ,” Barten said.
This structural steel company purchased several Peddinghaus automated processing machines, including Advantage-2 drilling line, BDL/B drilling line, DG-1250 band saw and PeddiWriter layout marking line. “Usually, the accuracy of the equipment is within 1/32 of an inch,” Batten said.
”We processed a large number of plates for the Washington Avenue Bridge, the large underground auditorium and the Bank of America Stadium. We also have Peddinghaus ABCM-1250/3D, which can be used for bevel cutting at the end of the beam, as well as for welding preparation, cutting Type and beam for welding penetration.”
Since automation, manufacturers have produced more than 30,000 tons of steel per year. Barton said automation has greatly increased the company’s steel processing speed. In addition, it can do this without increasing labor costs. “Although the complexity of the buildings we manufacture continues to increase, our annual output continues to grow without actually having any significant additional labor time. In fact, this has actually been reduced. So, I think this Is a major benefit,” Barton said.
The king truss of the large auditorium was assembled on the floor of LeJeune’s manufacturing plant. Photo courtesy of LeJeune Steel Co.
LeJeune Steel’s first project was the use of new CNC equipment to transform the Washington Avenue Bridge in Minneapolis. This bridge is located on the main campus of the University of Minnesota and connects the east and west banks of the Mississippi River.
The bridge renovation project is estimated to require 450,000 holes to be drilled in the slab and box girder. The box girder is manufactured at LeJeune’s Minneapolis plant and then trucked to the company’s subsidiary manufacturer Wisconsin Structural Steel plant, passing through the Peddinghaus BDL/B drill line.
Batten said: “In this work, there are thousands of holes. Due to the precision of the CNC equipment, less than 10 holes must be reamed to fit the site.”
”The customer was ecstatic. The project really set the tone for future projects and also set the tone for our level of confidence in automation equipment. This is a milestone for LeJeune,” Barten said.
LeJeune Steel/Wisconsin Structural Steel was selected to provide steel roof trusses for the auditorium of a healthcare software giant. Batten said that the underground arena is a fascinating building in many ways, especially challenging in terms of scale and complexity.
The five-story, 1.2 million-square-foot auditorium was built in a 74-foot-deep underground excavation. The 25-foot-deep, 270-foot-long roof trusses above the seating area are all tied into a large king truss on the stage. The large-span roof is one of the most challenging components of the project.
The entire 4,200-ton roof structure-a complete large-span truss king truss-is assembled on the ground and then twisted and fixed in place. Then, place the pillars under the roof and lower the roof to the top.
The thickness of the truss panel exceeds 41/2 inches. Sometimes steel is four to five different steel layers, making it 12 to 14 inches thick.
This project requires extremely high precision in the position of the joint plate and string joint bolt holes. “We have to align the holes. We can’t afford the holes we missed.”
In LeJeune’s factory, a part of the Queen’s Pillar was built and constructed to construct an underground auditorium with epic proportions.
Barten said CNC machinery provides the cut and hole precision required for truck assembly. “In the past, we had to do a lot of work to ensure that even relatively simple connections can be secured together on-site near the truck. Automation makes more complex tasks suitable for the first attempt.
”Unless you have very good equipment, you won’t be able to get such accuracy,” Batten said. “We rely heavily on Peddinghaus CNC automation equipment.”
The success of these projects has strengthened the company’s confidence in taking on another unique and even larger job. Barten pointed out that the truss the company made for the Bank of America Stadium is an example of the convenience and accuracy that automated machinery can achieve. Button said that the manufacturing of this 66655-seat stadium is challenging and automation equipment is essential.
The expectation of expedient measures is a big challenge for stadium construction. “They dismantled the Metrodome at the end of a football season, and they hope to install it and run it in a year and a half so that it can start on the opening day of 2016. To be able to make steel at this speed, we have to be fast, Batten Said, and added: “We can’t do this without automation. “
The second challenge is that the design of the stadium roof is very complicated. Each truss section entering the main assembly has up to 50 separate section cuts to aid assembly. The stadium roof truss weighs 6,000 tons.
”In this work, the most important and most impressive steel member is the queen column truss.” These are the trusses that extend from the central ridge truss, which extends along the length of the building to the perimeter. “The nine trusses are four chord trusses-two tops and two bottoms-and then tie them together with the filler. In addition, there is a large tension truss under the queen column trusses.”
The trusses were built and painted in various parts of the store. “Because of their size, we can actually only assemble a 40-foot device. It is displayed in our shop at a time.” Then they are brought to the job site, assembled on the ground, and then lifted into place, or In some cases, it is assembled into the air. On-site and aerial assembly means that the position and dimensional accuracy of the holes are critical.
The bolt connections (splicing plates) at both ends of the string must be placed together very precisely. The overall geometry of each truss must be precise so that all parts fit together. “We used the Peddinghaus BDL/B drill line and the DG-1270 band saw to process each chord. Then, we used two different board handling systems to cut the splicing board and all the filling and connecting boards.”
Barten said that the whole process went very smoothly. “They have no problem at all. Without CNC equipment, the geometric complexity and all the connections of the back column truss cannot be completed. I think it is difficult for us to drill all these holes and make them manually without setting problems on site.”
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Post time: Sep-21-2020