BRIDGING THE GAP YOUR CONNECTION TO ENGINEERING SERVICES

Echo Summit Raises the Bar for Bridge Construction Timelines Construction on the Echo

Summit Sidehill Viaduct Replacement Project completed five days ahead of schedule thanks to multiple innovations implemented by the Division of Engineering Services’ (DES) Accelerated Bridge Construction team. Originally built in 1939, the bridge, which sits on a narrow and winding stretch of Highway 50 over the Sierra Nevada mountains towards Lake Tahoe, was crumbling away after years of corrosion from extreme temperature shifts and chemicals used to remove ice from the roads. The Echo Summit project presented many unique challenges, such as the location, steep mountainside, high altitude, potential rock falls, noise impacts to residents and wildlife, and the need to minimize disruptions to tourism due to traffic disruptions. Ultra-High Performance concrete (UHPC) quickens the process UHPC is five times stronger than regular concrete and allows for a quicker beam reinforcement process, preventing use of an older method which takes extra time. “[UHPC] made it easier and quicker to construct,” said Dorie Mellon, a Senior Bridge Engineer in the Office of Bridge Design. “It took the risk out of the schedule.” Innovations Benefit All The bridge remained open to vehicles while contractors worked on the bridge foundation and substructure, allowing for reduced road closures. Once the road was fully closed, construction was completed in nine days. Closing the bridge to traveling public eliminated the risk of traffic accidents and helped reduce the risk of work zone accidents. Moving forward, DES looks to use UHPC in other projects. A recent replacement of the 21st Avenue Undercrossing on Highway 99 in Sacramento used the same method of construction which only shut down the commute for four days. “This is how innovation evolves. Continuous quality improvement. Move faster with a lot less risk,” says Mellon.