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Case Studies
> Facilities and Structural Modifications
> Fairwinds Clamp Repair Solution
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Fairwinds Clamp Repair Solution
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In 2010, an operator came to Fairwinds with significant damage to their 4-pile structure located in approximately 200 ft. of water. An underwater inspection after a hurricane showed significant structural damage in a critical joint connection. This damage required an engineered permanent repair in order to restore the structure to its original strength and withstand future storms. Fairwinds immediately went to work engineering a series of three repair clamps to fix the damaged section of the jacket. We calculated the required hurricane design loads the clamp must withstand and ensured the clamp design adhered to the latest design codes and practices. The clamp design was submitted to the Bureau of Ocean Energy Management (BOEMRE), and was subsequently approved for installation.
After completing the initial engineering and permit approval process, Fairwinds was tasked to manage the repair clamp fabrication. We provided inspection services during the fast-track fabrication schedule. Following completion of the fabrication, we then provided installation phase offshore inspections.
Shown in the first picture below, two small 14-inch horizontal diagonal braces were initially cut back from the damaged connection, in order to install the first main K-clamp, designed specifically to fit around the K-joint of the damaged jacket node. Early in the engineering process, dive measurements were taken to guarantee the clamp would fit around the damaged jacket node. With the first clamp set in place, two smaller 14-inch clamps were installed to fit around the 14-inch horizontal diagonals, which had been previously cut back in order to install the large K-clamp. All three clamps were temporarily secured with a series of short bolts. From the surface, the annulus of each clamp was filled with grout which was then tested for strength and allowed to set. Long tensioning bolts were installed by divers along the perimeter of the clamps and were then mechanically tensioned with a required pre-designed load. This secured the clamps to the jacket and enabled load transfer through the jacket to the clamps. Through a custom-engineered solution by Fairwinds, the jacket was brought back to its original design strength.
K-Node Structural Repair Clamp
Horizontal Structural Repair Clamp
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