Friday, September 14, 2018

Drone technology: Saving time and highlighting safety following SR 11 rockslide

By Andrea E. Petrich

Technology. It can create some dangerous situations, like when people are paying attention to their phone rather than the road when driving. It can also help with safety, like it did this week on SR 11/Chuckanut Drive in Skagit County.

A rockslide has the highway blocked between Chuckanut Ridge and Pacific Rim Drives south of Bellingham. The slide also left the highway at risk due to more potential falling debris from the ridge above.
A rockslide on SR 11 at milepost 12 has closed the  scenic highway between Chuckanut Ridge Drive and Pacific Rim Drive.

Evaluating the condition and risk used to mean roping up the ridge, anchoring into a spot and evaluating, then coming down and repeating over and over. Not only is this incredibly time consuming, it can also potentially put the evaluator at risk.

Enter the drone. By deploying an unmanned aerial vehicle, our crews are instead able to get a clear, close-up view of areas that otherwise would be difficult and risky to reach and make evaluations and decisions much more quickly and safely than in the past.
Maintenance lead, Joe Wyman, a Skagit County native, measures some of the rocks that fell. Once the area is safe for equipment, his team will come in, breakup these large pieces, some are 5-7 feet long, and haul them out of the area.

Closing the road
Heavy rain on Wednesday, Sept. 12 led to the rockslide on SR 11 between Burlington and Bellingham. Our maintenance team arrived on scene and shut down the road at milepost 12 just north of Taylor Shellfish Farms. Supervisor Joe Wyman, a native of the Skagit Valley and someone who knows the terrain as well as anyone, saw that there was likely still some risky areas above the highway and called in our geotechnical team to take a look.

Upon arriving, geotech Mike Mulhern saw some overhang areas with cracks and others penetrated by scotch broom and other roots that could be at risk of falling onto the road, especially if more wet weather arrived. Keeping the highway closed overnight would allow our crews to get a better look at the condition before deciding next steps.
Mike Mulhern, a WSDOT engineer with our geology team, measures distances in the slope along SR 11 just south of milepost 12.

Enter the Drone
Rather than have our geotechs rope up onto the ridge to evaluate, our IT drone operators were dispatched to the scene from Olympia. Drone operator Peter Burkhead was able to fly the UAV along the hillside. The video from the drone streamed down live onto a screen in our mobile operations video, allowing our geotechs and maintenance crews a clear look at the conditions, giving them all the information they needed to make an assessment.
This saved a tremendous amount of time and also kept our workers safely away of potential hazards.
Members of our SR 11 maintenance team view drone footage live from the back of the mobile command vehicle.

What's Next
The road will stay closed at least through this weekend and won’t reopen before Monday, Sept. 17. We’re bringing in an emergency contractor trained to safely remove the debris threatening the highway. Once the threat above the road has been removed, our maintenance group will use a loader with a rock-breaker to bust up the larger rocks – some measure 5 to 7 feet across – and haul them out of the area. At that point we’ll be able to reopen the road, but we don’t yet know when that will be and some of it depends on the amount of rain we continue to get. The latest updates can be had by following us on Twitter. Until then, people who typically drive on SR 11 should stick to I-5, and those who bicycle on the highway may consider using county roads. It may not have the same view, but like our use of drones, it will keep everyone safer.