Photo courtesy of Drill Tech Shoring & Drilling
Construction crews from Drill Tech Shoring & Drilling have installed steel rock dowels 40-ft. deep for the intitial start of repairs to prevent further cracking and erosion on Highway 154 in Santa Barbara County.
A crack across a section of Highway 154 and along the outer shoulder of a section of Highway 154 in Santa Barbara County has led to the closure of the two-lane highway (with shoulders on either side) from San Antonio Creek Road to Painted Cave Road.
The California Department of Transportation (Caltrans) District 5 has brought in contractor Drill Tech Shoring & Drilling Inc. to remedy a solution, which now has reached the point where drilling operations are under way to help repair the roadway.
Crews are installing steel rock dowels 40-ft. deep using drilling equipment.
"A horizontal drilling operation is now under way," Caltrans District 5 Public Information Officer Jim Shivers said. "This has been successful as there has been no additional roadway cracking … The insertion of vertical dowels 40 feet deep below the highway has stopped surface movement and further cracking of the pavement. In addition, inclinometers have been inserted into the slope to monitor sub-surface movement.
Photo courtesy of Drill Tech Shoring & Drilling
"A temporary soil bench was created just below the highway [slope] to place the drilling equipment on it to allow for horizontal drilling," Shivers added. "There has been some cracking at this location but has not stopped the progress of work."
Overall, work includes placing large rocks at the bottom of the slope to provide support. New drainage pipes have been installed with the rocks and pipes covered in Filter Fabric and then covered with additional material and protection.
Drill Tech has between five to 10 people on-site, which is supported by five Caltrans personnel.
"We have a good staff responding to this [situation]," said Shivers. "We have Caltrans engineers, CalPortland and Drill Tech [people on-site]. Relations are good."
Being in a more remote area, ensuring that equipment downtime is minimized is a given, as is having Caltrans people on-hand to respond to all contingencies.
"Maintenance is always on standby and is often our very first responders to these incidents," said Shivers. "They routinely patrol the area as they head to work and can tell if something has changed or doesn't look right. They should be mentioned for their overall support in these operations and often the people who set up the initial closures."
Drill Tech employs specialized equipment in many of its emergency operations.
"It's all proprietary DTSD equipment, which has been modified specifically for purpose," said Des Blake, a Drill Tech project manager, who commented about the company's equipment on its work to repair a section of the Pacific Coast Highway in Big Sur.
The base Hyundai machines were purchased from Mecom Equipment Company in Stockton and its crane rigging supplies are provided by West Coast Wire Rope in Oakland.
Roadway Repairs
"A drilling operation is now under way to support the roadway at this location which includes a slip-out in addition to the roadway cracking," stated an early an Caltrans press release. "This location is part of an ongoing emergency project to repair the slip-out when the roadway cracking was discovered. This drilling operation continues 24-hours a day with two shifts. It is unknown when Highway 154 will be fully open. The primary detour during this closure is U.S. 101 and State Route 246. Travelers and commuters can still use Highway 154 from State Route 192 in Santa Barbara and from U.S. 101 and State Route 246 but no one, including local traffic will be able to pass through the hard closure."
At this point, Caltrans engineers say the crack was caused by landslide activity, with cracking extending across all traffic lanes.
"This remains under investigation as drilling work continues and earthwork continues well down the slope," Shivers said when asked if this was just an isolated crack or does it extend over a greater area. "Drainage improvements down the slope are also underway. Large rocks are being placed at the bottom of the slope to provide support to the slope and roadway above."
Shivers added that he is not aware of previous cracks in this location.
Photo courtesy of Drill Tech Shoring & Drilling
The crack was discovered on June 22 during an ongoing emergency repair project to repair a slip-out. Drill Tech was able to send personnel and equipment to the site rapidly.
"We are also placing equipment into the slope to monitor any subsurface movement at depths up to 100 feet," said Shivers.
The repair work was designed by Caltrans Geo-Technical and design engineers and engineers who are experts in the application of pavement.
"Our management staff is always part of this process," said Shivers. "We have emergency contractors who can respond almost immediately to these incidents. The movement is an issue, and the insertion of rock dowels and grout provide support to the areas beneath the roadway."
The affected section is in a mountainous location, with slopes that have brush and rocks.
"Repairs can last for years with added routine maintenance," said Shivers. "Most of these locations are also the recipient of improved drainage facilities."
While the road is closed to traffic, it is considered safe to work on. The edge of the road overlooks a gradual steep slope below the highway with trees and rocks. Adjacent to the guardrail is a medium-sized dozer with a pick-up truck next to it and on the other side, a Hyundai drill rig on the shoulder. An air compressor on the other side behind the pick-up truck, has a line attached to the drill. With the road closed on either side of the work site, crews have plenty of space to operate.
A July 2 Caltrans situation update announced that one-way reversing traffic control utilizing a temporary signal on Highway 154 between San Antonio Creek Road and Painted Cave Road was anticipated to begin on July 4.
"It is not known at this time when Highway 154 will fully reopen," he added. "Upon completion of the drilling, Caltrans will monitor pavement conditions before making any determination about fully reopening the highway. In addition to stabilizing the slide, extensive pavement damage must be repaired before additional lanes can be reopened." CEG
Irwin Rapoport
A journalist who started his career at a weekly community newspaper, Irwin Rapoport has written about construction and architecture for more than 15 years, as well as a variety of other subjects, such as recycling, environmental issues, business supply chains, property development, pulp and paper, agriculture, solar power and energy, and education. Getting the story right and illustrating the hard work and professionalism that goes into completing road, bridge, and building projects is important to him. A key element of his construction articles is to provide readers with an opportunity to see how general contractors and departments of transportation complete their projects and address challenges so that lessons learned can be shared with a wider audience.
Rapoport has a BA in History and a Minor in Political Science from Concordia University. His hobbies include hiking, birding, cycling, reading, going to concerts and plays, hanging out with friends and family, and architecture. He is keen to one day write an MA thesis on military and economic planning by the Great Powers prior to the start of the First World War.
Read more from Irwin Rapoport here.
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