Harnessing water pressure to breakup boulders

Wednesday, April 16, 2014

By Doug Adamson

The power of water in the form of torrential rain can bring mammoth-sized boulders down onto state highways. The power of water can also be used to help get rid of them.

Sometimes, boulders that come down hillsides are too big to lift, even with an excavator. Maintenance crews then have to break apart large boulders using jackhammers, which leads to traffic delays. Explosives could be used, but they pose additional risks.

Enter the Boulder Buster™ - a portable rock-smashing tool that’s slightly bigger than a shoe box and uses pressurized water to break up or ‘blast’ large boulders.

But the ‘blast’ is not what you might think. Forget about Hollywood explosions. There are no giant booms, fireballs or flying debris. That’s the benefit.

Instead, the process produces a muffled ‘poof’ that might not even startle a dog, let alone the people who live nearby. The non-detonating rock-breaking tool – which uses just a bit of gunpowder and water pressure - breaks a rock open like an egg. A heavy plastic cover limits flying debris.

This tool can be safely used near pipes. It also is safe to use near structures and much safer overall when compared to something like dynamite.

Much safer compared to dynamite, the Boulder Buster™ breaks
up boulders with a muffled ‘poof.’
During a recent training session on a windswept State Route 112 in Clallam County, maintenance staff took advantage of a Boulder Buster™ training session to clear the roadway shoulder of several big boulders that had come down in a recent slide. Maintenance crews who took part in the training exercise became qualified to teach others at our agency how to safely use the Buster.

After the rock-busting session was complete, the remnants of the boulders were used as fill for another project.

So, how does it work?

First, we drill a hole about 75 percent through the boulder. Then, we pour the “secret ingredient” – water – into the hole.
Pouring water into the breech body
Next, we place the “breech body” inside the hole. It’s similar to a cast iron vase that has no bottom. A heavy plastic cover, similar to an industrial-sized door mat, then goes over the breech body, followed by a single shotgun shell-sized cartridge.

A representative from Boulder Buster™ leading the training.
A metal top that works as the firing mechanism is screwed to the top of the boulder. We then attach a lanyard, go a safe distance away and pull once on the “trigger” – a rope.

The boulder busting aftermath.
With the telltale ‘poof,’ the boulder breaks apart.

Pass clearing continues on North Cascades Highway

Tuesday, April 15, 2014

By Jeff Adamson

They’re back…Pink Floyd and his family of avalanche safety flamingos. Yes, they ARE cute, but they have an important duty.

Pink Floyd pointing out
work zone hazards.

The flamingos are eye-catching tools that point out hazardous zones to the snow removal teams. They’re reminders to always have your “avalanche eyes” open for chutes, debris, another work crew and other hazards. Now if we could only agree on which song to go with our mascot...

East side update

On Monday, April 7, Pink Floyd joined the east side snow removal effort on SR 20 – North Cascades Highway as the team’s avalanche training refresher at Silver Star Gate kicked off the second week of this massive snow removal project . Then it was off to begin clearing just above Lone Fir Campground.

While the maintenance crew pushed and blew snow from SR 20, the avalanche team climbed to the 6,200-foot-level up Liberty Bell Mountain.
Snow blower at Lone Fir Campground.

Spring’s rising temperatures can trigger snow slides below – a major hazard for crews. The avalanche control team dug a snow pit and assessed the Liberty Bell Mountain zone to determine which layers of snow might separate and slide. It tells them what the avalanche potential is and what kind of snow movement to look for when the maintenance crew progresses into the giant Liberty Bell avalanche zone.

In years past, the avalanche control team doesn't join the clearing effort until the east side maintenance crew reaches Cutthroat Ridge in the second or third week. The zone has 12 active chutes.  This year, the avalanche team has been on site monitoring unstable slopes since week one. Most of the winter’s snowfall didn't start falling until mid-February so what’s on the slopes isn't as stable as snow that’s spent all winter compacting on itself.

A second bulldozer joined the east side clearing effort.
Last week, the two teams joined to take on Cutthroat Ridge and by week’s end, they had cleared through Cutthroat Ridge avalanche chute 8 at milepost 164.5.  Think of a layer cake. A snow blower can handle six-feet or so of snow no problem. In an avalanche zone, a snow slide can be 10 times that height and as wide as a football field.

The solution is to cut the top layer off (anything over 6 or 8 feet) and the tool of choice is a bulldozer or two. Through the Cutthroat zone, a D-6 caterpillar worked the top of the slide and when its work was done, the maintenance crew’s excavator, snow blower and a grader cleared the snow down to the pavement.
When they get to the end of the Cutthroat zone, a larger D-8 cat we lease from a local logging company joins the effort to cut down the top layer of the more than 30-foot-deep slides in the Liberty Bell Mountain zone.

West side update

Eastbound SR 20 clearing continued on Monday, April 7, just beyond the Canyon Creek Trail.
Snow blower on SR 20
just below Easy Pass.

By the end of week two, the two-man team had eastbound lanes cleared and widened to about three miles short of Swamp Creek. The less-than-a-foot snow depth increased to 4 feet as they worked towards Rainy Pass. Next, the team will be moving forward towards Easy Pass.

Here are some short answers to questions you might have:
  • The closure gates stay closed until the entire highway is reopened (estimated about the second week in May)
  • No licensed motor vehicles are allowed beyond the gates, but boots, bikes and snow mobiles are.
  • We work Monday through Thursday, leaving Friday through Sunday for uncontested(!) recreation, but we encourage you to check the back country avalanche forecasts and weather before you go  
  • We also ask you to stay clear of our clearing equipment so no one gets hurt or hurts it

Check out photos from the SR 20 North Cascades Highway snow removal project on Flickr.

1 million gallons of biodiesel fuels WSDOT on road to greener, more sustainable transportation

Thursday, April 10, 2014

By Noel Brady

Our fleet of trucks and ferries recently realized a seven-digit milestone on the road to sustainability. For the first time, the agency’s fuel purchases in 2013 included more than 1 million gallons of biodiesel for ferries and mid-to-large-size trucks and equipment.

That means a net savings of more than 1 million gallons of regular diesel, including 687,741 gallons used for ferries and 318,775 purchased by the land fleet to fuel work trucks and other heavy equipment. It’s big news for Washington, where transportation ranks the largest source of greenhouse gas emissions. And it’s the latest green thumbs up for WSDOT’s award-winning fleet.

According to the U.S. Environmental Protection Agency (pdf 753 kb), substituting biodiesel, which is derived from vegetable oils and animal fat-based oils, for petroleum-based diesel can reduce smog-forming emissions from particulate matter by 10 percent, hydrocarbons by 21 percent and carbon monoxide by 11 percent for highway vehicles. Hydrocarbons are greenhouse gases that contribute to climate change.

WSF’s fleet of vessels each use up
to 5 percent biodiesel. Soon WFS
will launch a pilot project to study
the feasibility of using up to 10 percent
biodiesel to fuel ferries.
Increasing the use of biofuels, such as biodiesel, is a widely accepted strategy for slowing climate change. Since biodiesel is derived from plant matter, it is not a fossil fuel, so it’s renewable. Biofuels come from plants and trees, which need CO2 to grow. Using biofuels doesn’t add as much CO2 to the atmosphere; it recycles it.

Considering these factors and others, a 2006 study published in the scientific journal Proceedings of the National Academy of Sciences (PNAS) found that biodiesel can reduce greenhouse gas emissions by 41 percent.

The benefits of biodiesel are clear, and we plan to continue
growing its use as an alternative fuel, said WSDOT Energy Policy Manager Tim Sexton. Washington State Ferries uses biodiesel made primarily from recycled canola oils. WSF is preparing for a pilot project to evaluate increasing the percentage of biodiesel it uses to fuel vessels.

Into the green fleet first

Since 2009, use of biodiesel and other alternative fuels, such as propane and electricity, has helped WSDOT’s  fleet cut greenhouse gas emissions by 263 metric tons of CO2 equivalent. Since 2008 WSDOT also:
  • Reduced employee travel by 2.2 million miles
  • Cut fuel consumption by 10 percent or about 400,000 gallons
  • Purchased plug-in hybrids, all-electric vehicles and charging stations

Source: Washington State GHGEmissions Inventory 2009-2010

Slope stabilization – using proactive strategies in a constant battle of nature

Thursday, April 3, 2014

Our hearts are with those affected by the SR 530 Slide, and thoughts with those who continue to toil through the debris.

Photo of debris field on SR 530 near Oso.
The extreme reach of this landslide was catastrophic, and it’s not an event that WSDOT would have expected to impact the highway, given that the slope is on the opposite side of the valley.

WSDOT tracks known unstable slopes adjacent to state highways and Interstates. With the recent slide near Oso being more than a mile away and across the North Fork of the Stillaguamish, it’s not one that was included in our slope database. Prior to 1995, unstable slopes were stabilized reactively after they had failed. Since then, we’ve been proactively tracking problem slopes next to our roadways – slopes that have the potential to threaten the highway and its users.  Typical slope hazards that we manage include landslides, debris flows, rockfall, settlement, and erosion. Currently, we’re keeping tabs on about 3,300 locations which can be found on the map below and in this list (pdf 648 KB).

Map image of unstable slopes by rating (pdf 3.6 MB)

Each identified location receives a score ranging from 33 (lowest) to 891 (highest), which is based on the potential risk factors to the usability of the highway if a slope failed. This is helpful so we can strategically determine which slopes should be addressed with the limited funding available. With this management system, we’ve worked to stabilize about 244 slopes adjacent to state highways and Interstates since 1995 at a cost of $180 million, using both federal and state funds.

One example is I-90 over Snoqualmie Pass.

Photo of nail wall being installed along I-90 at Snoqualmie Pass.

As part of the five mile project to widen I-90 from four to six lanes, crews are working to significantly reduce the rockfall hazards that are present by constructing more stable cut slopes, heavily reinforcing these cuts with rock anchors, and providing more catchment area for the natural, ongoing weathering of these new slopes.

Another is a stretch of SR 20 near Rockport that is constantly buffeted by the Skagit River, especially during flooding. When the river runs high, it eats at the riverbank and, at times, has threatened to even wash out the road. Right now we have a project in construction that is building logjams with something called dolos to protect the riverbank and our highway from continued erosion.

Photo of Skagit River - Permanent restoration using engineered logjams
combined with concrete dolos.

The geology of our state is complex and dynamic, and conditions are subject to change. With potential problem areas identified, our maintenance staff who drive these areas every day are on the lookout for developing problems, such as new rocks in a ditch or dirty water that wasn’t there the day before. This points our geologist to a spot that may be changing and is worth a closer look. If it’s determined that a highway is unsafe for travel, we’ll close it until it can be made safe.

SR 20 - North Cascades Highway snow removal is underway

Wednesday, April 2, 2014

Clearing work began this week to open State Route 20 - North Cascades Highway.

Snow blower clearing nearly a foot of snow from the west side of SR 20 at Diablo Gate.

East side progress

Maintenance techs from Twisp set off Monday, March 31, to start blowing and pushing snow from the closure barricades at the Early Winters Information Center up to the Silver Star Gate. That’s a seven-mile stretch on the east side of SR 20.

Crews had cleared two snow blower widths of snow from between those mileposts by Tuesday evening. Clearing work begins today on the shoulders and pullouts throughout that area in addition to the parking and turnaround space at the Silver Star Gate.

In years past, maintenance techs start the clearing process on either side of the pass. An avalanche control team member joins the process once the crew reaches the Cutthroat Ridge avalanche zone to watch for avalanche activity. That person is essentially a spotter for those clearing the highway.

This year is different.

Crews discovered during their assessment last month that Delancey Ridge avalanche zone had come in with snow and debris reaching the road – a first in recent memory for our clearing team.

With that much snow, maintenance crews need their spotter early. They’ll be joined by a member of the avalanche crew on Monday, April 7.

West side progress

Work on the west side began Tuesday, April 1, once maintenance technician Bob Hopfield took control of his usual spring “ride” – a loader-mounted snow blower – at Diablo Gate.

An in-progress view of the Rudy
Ridge snow slide clearing process.
Before he arrived at SR 20, Hopfield had been assisting State Route 530 slide emergency response operations along with many others from WSDOT.

The snow depth at Diablo Gate has melted down to less than a foot deep. Further up the highway, the snow is nearly two-feet-deep. The Ruby Ridge avalanche zone has been active as well, with chute #10 covering both lanes of SR 20 with a dozen feet of snow. This is a relatively small slide.

By the end of Tuesday, the crew had cleared a single lane all the way to milepost 144, just before East Creek Trail. Next up is widening the cleared area and tackling the clean-up of the Ruby Ridge avalanche zone slide.
A bank of snow on the shoulder
of SR 20 at the Ruby Ridge slide. 

Late snow meant a late start to snowmobile season this year. The west side clearing team is leaving snow on the westbound SR 20 lanes from the gate to Granite Creek for up to two extra weeks to give snowmobilers more time on the snow. The beginning of westbound lane clearing and ditching work will mark the end of snowmobile season from the west.

In the meantime, crews are clearing and widening only the eastbound lanes for the 14 miles up to Granite Creek.

For the latest SR 20 – North Cascades Highway news, visit our website or sign up for email updates. See even more SR 20 clearing photos on Flickr.



    Follow us on Twitter

    Featured Flickr Photo

    see caption
    Pontoon P travels under the Montlake Bridge

    Blog Archive