CSDA Member Scores Big with Sports Stadium Upgrades
(Photo Courtesy of the University of South Dakota)
The University of South Dakota’s Athletics Department recently made renovations to its flagship building, the DakotaDome, as part of a wider $66-million new construction project. This renovation work consisted of cutting 8-foot-wide pre-cast concrete pieces from the walls of the dome, the top cuts being 30 feet from the ground, to create 25-foot wide and 24-foot tall openings.
The university has broken ground on a Sports Performance Enhancement Facility Arena, a Science, Health and Research Lab and an Outdoor Track and Soccer Complex. The three projects are projected to be completed before the start of the 2016-17 academic year. Openings created in the DakotaDome are being used to install structural steel that will support a connection point between the dome and the new facilities. They will also create viewing windows that overlook H. Lauren Lewis Field for members of the university’s sports clubs to watch games from above the south end zone.
CSDA member Northwest Concrete Cutting & Crane Service of Sioux Falls, South Dakota, was contracted by Mortenson Construction of Minneapolis, Minnesota, to create the openings using diamond tools. The task involved cutting partial sections of existing concrete wall panels that each measured 24 feet tall, 8 feet wide and 3 inches thick with 13-inch-thick T-stems that had seven post-tensioned cables. There were five openings specified to be cut and removed by crane. The width of two of the openings spanned two separate panels, another spanned four panels and two openings for walkways each spanned one panel. The cutting contractor was also responsible for flat sawing and removing an 11-foot-wide and 180-foot-long section of 10-inch-thick asphalt. This would provide the general contractor with an area to install footings for structural steel as part of the new construction. The first task for Northwest was the cutting and removal of the asphalt floor section. A 40-horsepower electric flat saw from Diamond Products powered by an 80-kilowatt generator was used to make the cuts, while the contractor’s skid steer was fitted with a scrubber to haul the cut pieces to the disposal point. A spotter walked behind the skid steer at all times to eliminate the possibility of passing students being hit. This task took around 24 hours to complete.
Next, the cutting team carefully planned and set up the work area for the removal of the wall panels. Working on a dome structure with limited access points, the contractor had to be conscious of the existing construction and red iron being installed for the new construction. Operators were left with 4 feet of space from the dome walls on the exterior of the new building, with some cut points positioned 45 feet from the ground. Where the precast panels formed T-stems, the working space was just 2 feet. To perform the job safely and efficiently, a swing stage was used and was mounted to the roof of the dome.
Once the swing stage was set in place, layouts and other preparatory work for cutting was completed. Meanwhile, on the inside of the dome, two men, including a certified crane operator, set up the crane for the safe lowering of the cut pieces. Two concrete cutting operators were positioned on the swing stage and drilled two holes so that rigging could be passed through and secured. This involved bolting on two swivel hoist rings that were each rated for 15,000 pounds. All required items of rigging, hoisting and personal protective equipment were provided by Northwest, including harnesses and hi-visibility vests.
The cutting process for successfully removing the wall panel sections meant splitting each one into three pieces, each weighing 5,600 pounds, and cutting through some T-stems. It was specified that the contractor was only allowed 1,500 pounds of weight per square foot for crane pads and a hauling cart. This was to avoid damaging the asphalt under the football field surface. First, the contractor cut a 2.5-foot-tall section from the top of the panel before proceeding to cut pieces that were each 10.75-foot-tall. Operators on the swing stage used a K2500 hand saw and a K3600 MKT ring saw from Husqvarna Construction Products, with each cut across the panel and T-stem taking approximately one hour.
Once cutting was complete, the piece was lowered to the interior floor of the dome before being removed from the building by trailer. By dissecting the cut sections into three pieces, the contractor made sure that the weight of the concrete being lowered was under 70% on the crane’s load chart. When all panel sections had been removed, Northwest was required to go back to the openings and cut the T-stems at an angle for roofing contractors to tie into.
The cutting of the wall panels came with some challenges, as the dome was operational and student athletes from the university were attending practice sessions within the building. When a cut section was secured on the trailer and ready to be transported out of the dome, the team used a combination of warning lights and spotters to avoid potential hazards. Once safely outside, a 12,000-pound all-terrain lift was used to move the cut pieces to the disposal point.
The use of a swing stage was a first for some of the cutting contractor’s operators, but safe practices were adopted to ensure a sturdy work platform. Training was provided on the safe use of the swing stage and the operators were given time to familiarize themselves with correct operation of the equipment. By ratchet-strapping each corner of the stage to an anchor in the wall, it was kept tight to the dome wall and was prevented from moving while cutting. The summer heat and humidity also presented a challenge. Operators wore harnesses and were positioned from 22 to 45
feet up on the swing stage in July with temperatures of up to 97 degrees. A cooler of water was placed on the stage and refilled whenever possible. A temporary cover was also set up above the cutting area to provide shade.
During the DakotaDome job, Northwest Concrete Cutting & Crane Service operators completed 320 linear feet of hand sawing and ring sawing, flat sawed 870 linear feet of 10 inch asphalt, hammer drilled 40 holes for crane rigging and removed all asphalt and concrete to a dumpster on the opposite end of the dome. The job took four weeks to complete and involved the removal of over 75,000 pounds of concrete.
“Being selected for this project came down to a few reasons. Northwest Concrete Cutting & Crane Service has NCCCO certified crane operators, riggers and signal men on staff. We also have a good reputation for doing quality work with good time management. We have shown many customers that we complete work in a clean and safe manner. Our experienced staff provide us with the ability to rise to all challenges placed before us. We take on the tough projects and figure out the best solution,” said Don Lueders, president of Northwest Concrete Cutting & Crane Service.
Click here for a short video showing some of the work: https://youtu.be/Qi0EK5XbyAE
Northwest Concrete Cutting was established in 1981. Mr. Lueders purchased the company in 1999. The company recently rejoined CSDA in 2014. The company is based in Sioux Falls, South Dakota, and services the Dakotas and surrounding states. Northwest Concrete Cutting & Crane Service has 14 trucks, eight operators, two certified crane operators, three certified rigger & signal men and offers concrete cutting services of flat sawing, core drilling, wall sawing, hand sawing, wire sawing, concrete grinding, concrete repair and concrete polishing.
MA Mortenson Construction
Sawing and Drilling Contractor:
Northwest Concrete Cutting & Crane Service
Sioux Falls, South Dakota
Methods Used: Flat Sawing, Hand Sawing