Re:Watching a Ridge Slide in Slow Motion, a Town Braces for ...
by jonknee on Tuesday January 23, 2018 @12:40PM
(#16215447)
This article has a LIDAR (I believe) image showing the movement... Scary stuff, especially when you see the date stamps between images. It's like watching geology on fast forward:
Re:Watching a Ridge Slide in Slow Motion, a Town Braces for ...
by poulsbohemian on Tuesday January 23, 2018 @12:01PM
(#16215050)
Drove through there last week. The state has 40ft containers at the bottom of the hill as barricades, plus there is a low spot below the area that is cracking. That stated, there isn’t that much room there for all the dirt that is likely to come down and even to a lay person it looks very reasonable to assume the highway will be unavailable for some time after it finally gives way.
Re:Watching a Ridge Slide in Slow Motion, a Town Braces for ...
by unspecified on Tuesday January 23, 2018 @03:49PM
(#16217552)
Just to be clear, those containers are only a barricade against falling rocks while the road is still open. If the ridge does let go, those barricades are going to do exactly nothing.
Re:Watching a Ridge Slide in Slow Motion, a Town Braces for ...
by jonknee on Tuesday January 23, 2018 @12:37PM
(#16215419)
Hence the "generosity" of the mining firm:
> The company that runs the quarry has stopped operations and has voluntarily offered to put up evacuated residents in nearby hotels for five weeks at its own expense, though the cause of the crack has yet to be formally determined.
> If we start removing material or blasting it from the hillside, it will actually make the area more unstable, creating fissures in other areas and would likely release larger amounts of debris in an uncontrolled manner. For some perspective, we’ve spent the past several years blasting rock from the hillsides along I-90 as part of the project to stabilize rock slopes and add more lanes. When we blast, it’s in very small sections and then we excavate any loose material after the blast. Over the past five years we’ve removed a little more than one million cubic yards of material – or about 200,000 cubic yards every construction season (April through October). The Rattlesnake Ridge slide is made up of about four million cubic yards of material.
> Also, blasting an unstable hillside simply isn’t safe. In order to do a controlled blast, crews need to drill into the hillside about 20 to 40 feet to put live charges into the hole. With the hillside moving, being able to drill accurately while also not causing more instability would be incredibly challenging. Even if the holes were drilled accurately, there’s the possibility that the charges won’t go off, meaning the crews would then have to sort through millions of cubic yards of debris looking for live explosives that could go off. It’s just too dangerous of a situation to put workers in.
Re:Watching a Ridge Slide in Slow Motion, a Town Braces for ...
by trhway on Tuesday January 23, 2018 @04:12PM
(#16217749)
>In order to do a controlled blast, crews need to drill into the hillside about 20 to 40 feet to put live charges into the hole. With the hillside moving, being able to drill accurately while also not causing more instability would be incredibly challenging. Even if the holes were drilled accurately, there’s the possibility that the charges won’t go off
with laser guidance and at $150K that would probably be more precise, safe and efficient tool for that job here - https://en.wikipedia.org/wiki/GBU-28
https://www.seattletimes.com/seattle-news/science/dramatic-n...
https://wsdotblog.blogspot.com/2018/01/crews-monitoring-land...
[0] https://www.youtube.com/watch?v=7DATFoizswY&feature=youtu.be
> The company that runs the quarry has stopped operations and has voluntarily offered to put up evacuated residents in nearby hotels for five weeks at its own expense, though the cause of the crack has yet to be formally determined.
> If we start removing material or blasting it from the hillside, it will actually make the area more unstable, creating fissures in other areas and would likely release larger amounts of debris in an uncontrolled manner. For some perspective, we’ve spent the past several years blasting rock from the hillsides along I-90 as part of the project to stabilize rock slopes and add more lanes. When we blast, it’s in very small sections and then we excavate any loose material after the blast. Over the past five years we’ve removed a little more than one million cubic yards of material – or about 200,000 cubic yards every construction season (April through October). The Rattlesnake Ridge slide is made up of about four million cubic yards of material.
> Also, blasting an unstable hillside simply isn’t safe. In order to do a controlled blast, crews need to drill into the hillside about 20 to 40 feet to put live charges into the hole. With the hillside moving, being able to drill accurately while also not causing more instability would be incredibly challenging. Even if the holes were drilled accurately, there’s the possibility that the charges won’t go off, meaning the crews would then have to sort through millions of cubic yards of debris looking for live explosives that could go off. It’s just too dangerous of a situation to put workers in.
with laser guidance and at $150K that would probably be more precise, safe and efficient tool for that job here - https://en.wikipedia.org/wiki/GBU-28
Btw, similar scale hillside slide in 2017 in Big Sur, Hwy 1 https://www.npr.org/sections/thetwo-way/2017/05/25/530025850...