Put Your Name On The Map
These points are far more than just projects we’ve completed. Each one is a story we love telling. Stories about how we can overcome any obstacle by working together as one, solving problems by innovating, executing plans with excellence, and making contractors look like the smartest human beings on the planet. The fact that we get to do it with the hardest working and most honest people in the Western United States is a huge bonus.
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On time. On line. On budget.
Tunneling construction begins on Highway 1 overlooking the cliffs along the Big Sur coastline.
The mudslide damage destroyed an entire section of Highway 1 causing a South bound closure.
A crane operator carefully lifts the tunnel boring machine into place.
The tunnel boring machine is at the entrance and ready to break ground.
The crew is excited to get the project underway.
The tunnel boring machine starts grinding its way into the slope under the highway.
The tunnel boring machine makes it to daylight on the other side of the steep slope.
The chinook helicopter lifts the sections of the tunnel boring machine to safety from the cliffside.
More boring work is needed to install better drainage along Highway 1.
Big Sur &
In late January 2021, a massive downpour caused a section of Highway 1 on California’s Central Coast to collapse into the Pacific Ocean.
A period of heavy rain accompanied by a flow of debris, trees, boulders, and mud caused severe damage near Rat Creek, ultimately washing a portion of the highway over the cliffside. This devastated the local economy, impacting residents, tourism, and businesses.
Caltrans prioritized the re-opening of Highway 1 and phased construction accordingly. Phase one involved the expedited rebuilding and opening of the highway.
Phase two included the installation of a new 10-foot-diameter culvert that would improve drainage beneath Highway 1 into the Pacific Ocean. Caltrans entered into an emergency contract with Papich Construction to rebuild the Highway. Papich Construction contracted with Pacific Boring, Inc. to install the new 10-foot-diameter culvert.
The installation required the team to overcome many obstacles including the setup, slope, and recovery of the machine. The culvert’s slope was designed at 30.56 percent downhill which is nearly 80-feet of fall over the 250-foot drive.
Setting up the equipment at such a steep slope required immense planning and creative adjustments. Conceptual drawings were made using 3D modeling, and the equipment was set up according to design slope in Pacific Boring’s yard. A custom guidance system was manufactured because standard lasers used to guide tunnel machines could not be dialed into this extreme level of slope.
Conventional haul equipment on rails couldn’t be used either due to the slope, so dirt buckets had to be removed using a large hydraulic winch. An Akkerman Excavator Tunnel machine was used to excavate the tunnel and was set up at Pacific Boring’s yard prior to mobilization to confirm the conveyor could load a dirt bucket at the required slope.
The greatest obstacle was the recovery of the machine. Because Highway 1 is on the edge of the Pacific Ocean, the machine had to come out the side of a cliff with no access down to the machine. To recover the machine, it was divided into three pieces that were then hoisted into the air using a chinook helicopter.
The Big Sur and Highway 1 project presented many challenges, but just 86 days after the start of construction, cars were driving along the highway once again.“Highway 1 was opened approximately two months ahead of schedule because of the decision to go trenchless and great collaboration among the project partners,” said Steven Gallyer, Pacific Boring president.
Both phases were completed ahead of the year’s wet season. Caltrans made quick decisions while working with Papich and Pacific Boring, relying on their expertise to carry out the work with excellence. The project was successful and completed in such a safe and timely manner because of the great partnership among team members, start to finish.
Tunneling Projects Completed Across The Western US
Linear Feet Tunneled Across The Western US
100 feet beneath the Los Angeles harbor, overcoming freezing temperatures, spouting leaks of icy sea water and gritty sand…
A failure of this 30 year old sewer pipe could have sent sewage into people’s basements; the pressure had to be relieved and the need for an expensive pump station eliminated…
More than a mile of tunneling was needed along the old Pasadena freeway, north of Dodgers stadium…