Rock Slide on Sea to Sky Highway

Rock Slide on Sea to Sky Highway

•The Issue

•Geology

•Short Term Solution

•Long Term Solution

Rock Slide on Sea to Sky Highway

The Issue

• Route 99 is the only direct route between Vancouver and Whistler in the North

• In July 2008 an estimated 16,000 cubic metres of rock fell on to the highway

• This led to a five day closure with thousands affected

• There are now major concerns about a re-occurrence during the 2010 Winter Olympic Games

Rock Slide on Sea to Sky Highway

The Issue

The slide occurred just North of Porteau Cove

Rock Slide on Sea to Sky Highway

Geology

• A geologically active region in steep mountainous terrain

• The bedrock along the route consists of highly fractured argillite and volcaniclastic rock

• The joints within the rock are at approximately 45 degrees

• The highway undercuts the rock structure meaning near vertical cliff faces along portions of the road

Rock Slide on Sea to Sky Highway

Geology

Steep joints are clearly visible

Rock Slide on Sea to Sky Highway

Geology

Landslide events in the last 150 years

Rock Slide on Sea to Sky Highway

Short Term Solution

• Re-opening of the highway was the top priority

• The newly exposed slope stability was assessed

• Loose rock from above was removed by rock scalers

• Plant at either end of the site used to transport the rubble away

Rock Slide on Sea to Sky Highway

Long Term Solution

• The future stability of the rock face along the highway needs to be ensured

• $775 million is being spent on upgrades to the Sea to Sky Highway and its surrounding rock structures

• To help prevent future slides pre-emptive blasting, rock scaling and rock bolting are being carried out

• The highway itself is undergoing widening

• There are calls for the construction of an additional route between Vancouver and Whistler