{"id":602,"date":"2008-08-01T08:19:00","date_gmt":"2008-08-01T08:19:00","guid":{"rendered":"http:\/\/blogs.agu.org\/landslideblog\/2008\/08\/01\/rockslide-on-the-sea-to-sky-highway-in-british-columbia\/"},"modified":"2010-10-21T13:55:13","modified_gmt":"2010-10-21T17:55:13","slug":"rockslide-on-the-sea-to-sky-highway-in-british-columbia","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2008\/08\/01\/rockslide-on-the-sea-to-sky-highway-in-british-columbia\/","title":{"rendered":"Rockslide on the Sea to Sky Highway in British Columbia"},"content":{"rendered":"

Hat tip to Scott McDougall<\/span>, Erik Eberhardt<\/span> and Andrew Giles, all from Canada, for this one.<\/span><\/p>\n

Many readers will be familiar with the classic book “Rock Slope Engineering” by Evert Hoek<\/span>, which still represents the bible for understanding the mechanisms of failure of hard rock slopes. The cover of the original version featured a photograph of a 1965 rock slope failure on the so-called “Sea to Sky” highway in British Columbia, western Canada:<\/p>\n

\"\"<\/a>This highway is the subject of some scrutiny at present as it represents the main transportation link between Vancouver and Whistler, which in 2010 will be hosting the Winter Olympics. The road, which has a history of being landslide prone, is currently undergoing a US$780 million upgrade. In Canada the national<\/a>, and indeed now the international<\/a>, press are quite exercised by a failure that occurred on this same road on the night of 29th July. Intriguingly, as Erik Eberhardt<\/span> has pointed out, this rockslope<\/span> failure occurred directly next to the 1965 failure featured on the cover of Evert Hoek’s<\/span> book:<\/p>\n

\"\"<\/a>Photograph, courtesy of Erik Eberhardt<\/span><\/a> of the University of British Columbia<\/a>, of the rockslide<\/span> on the Sea to Sky highway. Used with permission.<\/span><\/span><\/p>\n

This failure, which has a reported volume of about 16,000 cubic metres, has completely blocked the road and the railway. It appears to have occurred on a set of pre<\/span>-existing and somewhat unfavourable joints:<\/p>\n

<\/p>\n

\"\"<\/a><\/div>\n
Photograph, courtesy of Erik Eberhardt<\/span><\/a> of the University of British Columbia<\/a>, of the debris pile left by the rockslide<\/span> on the Sea to Sky highway. Used with permission.<\/span><\/span><\/div>\n

The scale of the landslide can be judged from this Reuters<\/span> image taken from a helicopter. Note the workers on the debris – some of the blocks are rather large:<\/p>\n

\"\"<\/a>Xinhua<\/span> \/ Reuters image<\/a> of the landslide debris. Note the block sizes compared with the workers.<\/span><\/span><\/div>\n

The inevitable media jamboree appears to be focused<\/span> on two elements:
1. At the time of the landslide there was a bus passing by that was fortunately not buried but was hit by some of the debris. This has given the media the opportunity to run the traditional story line of a narrow escape. This from the Toronto Star<\/a> (who incidentally have a great image of the slide taken from a helicopter, plus a video):<\/p>\n

Peter Skeels’s<\/span> bus was lumbering up the highway that winds through British Columbia’s breathtaking coastal mountains when he heard a roar that sounded like violent hail. He drove through and it wasn’t until a few minutes later, when Skeels<\/span> pulled over and saw the bus covered in dents and its windows shattered, that he realized a massive pile of rocks and boulders had rained down onto the road. “There was suddenly an unbelievable noise. It sounded like a hailstorm \u2013 you didn’t really know what to make of it,” said Skeels<\/span>.<\/span><\/div>\n

2. The inevitable concerns regarding access to the Olympic Games should such an event occur at the wrong moment. So, for example, Vancouver 24 Hours<\/a> have run this:<\/p>\n

Does VANOC<\/span> have a backup plan to get spectators to and from Whistler venues if a rockslide<\/span> closes the Sea-to-Sky Highway during the 2010 Winter Olympics? 24 hours requested an interview yesterday with VANOC<\/span> vice-president of services and transportation Irene Kerr but instead received prepared statements via e-mail. The responses credited to Kerr said VANOC<\/span> was deferring comment to the Ministry of Transportation. <\/span><\/p>\n

“Where is the contingency plan? What would they do in the event of a major accident or a landslide as we see here today?” said B.C. NDP<\/span> Olympics critic Harry Bains<\/span>. “When we are inviting the world, we need to assure them that they will be able to watch the Games, that they will not be stuck on some highway for hours.”<\/span> <\/div>\n

In the meantime, the clearance crews are working hard to deal with the debris and the obviously unstable portions of the cliff. CBC News<\/a> has posted this terrific sequence of images of an unstable block being blasted. This is accompanied by an impressively sensible analysis of the situation on the ground.<\/p>\n

\"\"<\/a>\"\"<\/a>\"\"<\/a>\"\"<\/a>Update: The Vancouver Sun<\/a> has printed some rather interesting statistics about the hazards of this highway:<\/p>\n