HK Gaskets and the Need for Speed
One of the rewarding experiences in life is watching a team pull together to accomplish a daunting task. Whether it’s a football team churning down the field on a game-winning scoring drive or an orchestra performing Beethoven’s 9th, when individual skills link with planning, coordination and teamwork, amazing things can happen. Construction projects can be like that too.
Case in point. The Resort Municipality of Whistler wanted to provide safe passage across a railroad line for cyclists and walkers using the Valley Trail near the Whistler Village resort. The developer originally considered a bridge overpass, but eventually settled on an underpass tunnel constructed from box culvert sections as the fastest, most cost-effective option. There was one major hurdle: because the project crossed two active rail lines, the contractor was given a 20-hour construction window to complete the entire installation. That’s where the teamwork comes in.
Enter Langley Concrete Group and Hamilton Kent. One of the leading precast concrete manufacturers in British Columbia with plants in Chilliwack and Victoria, Langley won the bid to provide 24 box culvert sections for the 30-meter tunnel. These were hefty boxes – 12’ by 10’ and 33,000 pounds each. They would need to be staged to arrive on site just in time, and had to be installed flawlessly to keep the project on schedule.
Joel Shimozawa, P.Eng., technical marketing engineer with Langley Concrete, said that the need for speed was definitely a major consideration on the project.
“We had to essentially mobilize the units and get them onsite in a timely manner,” he said. “So once they shut the rails down it was all hands on deck to get the thing installed. Any bit of time savings was a benefit to the project.”
And one of the biggest time savings came from Hamilton Kent. The tunnel had to be watertight and needed to withstand train traffic traveling above. So the boxes needed to meld into one tight structure. There was no time to mortar each box onsite. The solution was a gasketed box that would arrive ready to go, saving precious time and providing the critical watertight seal. Langley Concrete had switched from mortaring in the field to gasketing its boxes at the plant about seven years ago, Shimozawa said, so the specification was no problem.
“We made the change over to an engineered joint with a gasket to make things easier in the field,” he said. “That gasket was very important for this installation because of the groundwater, and being a pedestrian underpass, it had to be dry.”
Langley produced the boxes at its Chilliwack facility and was ready to go when the rails shut down and the excavation started.
“For all our box culvert applications we pre-install the gasket. For a box of that size it’s much, much easier for us to install the gasket before we ship,” Shimozawa said. “I think it is underestimated how much time that saves. We’re always harping the benefits.”
The project went off as planned. Langley’s team installed the pre-lubricated Hamilton Kent Tylox® SuperSeal™ gaskets at the plant. In addition, threaded rods in each corner prepared the boxes for post-tensioning.
“For a typical application, no post-tensioning would be required,” Shimozawa said. “But for this application, the engineer was concerned about vibrations from the trains.”
Once the first box was set in place, it was a plug and play operation, with each successive box sliding firmly into place aided by a box puller, which homes the joint and draws the gasket into a watertight seal. Within the space of 12 hours, the contractor excavated the site, compacted, placed bedding soils, installed the box sections, backfilled and reinstalled both rail lines. The team easily beat the timeline.
After every great performance, there’s an opportunity to praise your teammates, which is exactly what Shimozawa did.
“Hamilton Kent is obviously a very strong partner for us,” he said. “They’re always supporting us in the joint design and making sure they are providing us with the right gasket for the right application.”
Watch a time lapse view of the installation and read more about this project on the website of the American Concrete Pipe Association.