Deformations (Laser Profiling)
Far up north, at the Alberta Oil Sands Industrial Area, a section of Highway 63 was under construction. A 30 meter length of 1200mm diameter carbon steel sleeve was bored beneath the highway without impeding normal traffic flow. The 1200mm carbon steel sleeve was intended to act as a bypass duct for introducing utilities and other piping.
The Horizontal Directional Boring of the sleeve commenced and followed through to the other side of the highway where it was extruded with noticeable deformations. The internal diameter ended up at only 1000mm on the other side of the highway.
Engineers and consultants were wary about the possibility of even more damage to the pipe. Could it still be used to pull through the planned utilities despite the deformations? Confined space entry was discounted as a viable choice since the integrity of the pipe was not confirmed and was treated as unstable because of the known deformations. How could the engineers gather the information regarding the pipe’s internal diameter?
The plant engineers and construction groups called Maverick, who suggested the use of remote video technology and laser profiling to accurately measure the pipe wall surface and to provide deformation & deflection reporting with true internal diameter read outs. Maverick’s research & development team had to design and build a new skid-assembly for attaching the laser since the pipe wall roundness was obscured with deflections. A large robotic explosion-proof video crawler was used with the laser skid. The unit was also equipped with a built-in inclinometer providing the clients with real-time information on any pipe elevation changes while conducting the inspection.
A total of four passes, two from either end of the cast iron sleeve, were laser-profiled and video-inspected showing multiple areas of pipe sleeve with continuous deformations.
During the internal inspection of the metal sleeve, real-time video captured and recorded the laser-ring projected onto the pipe-wall surface while pulling back the laser-skid with the remote crawler. The recorded video documentation of the laser-projection was later transferred into a 3D machine-vision software which outputs various measurements and results, helping engineers to determine the exact starting and ending of the deformations with cross-sectional measurements and capacity reports. The ovality (out-of-roundness) of the sleeve was measured as high as 20.5% of the pipe diameter, leaving 79.5% of the pipe diameter available.
Maverick furnished the clients with a user-interactive disc including the 3D reporting so they could make the necessary adjustments for the new utilities to be installed with precision. The inspection revealed that even with the visible deformations of the pipe that no additional boring, no re-work and no new construction were required, saving the client thousands of dollars, and all without disrupting the flow of traffic along the highway.