# Active Landslide



## FLBuff PE (Apr 9, 2010)

I thought this would be interesting for everyone. This is an active slide that my company is analyzing. Note the anchors at the top of the slide. Also, they have lost about half of the road at the top. Two 100-foot inclinometers that were set in the slide failed with about 7" of movement at the top of the inclinometer in 2 days!


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## MGX (Apr 9, 2010)

Was this induced by rainwater or settlement or something else? What part of the country is this located in? Also, how does one stop or prevent something like this?

I'm part of a research team studying something similar. However, my role is minor but it is very interesting.


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## FLBuff PE (Apr 9, 2010)

MGX said:


> Was this induced by rainwater or settlement or something else? What part of the country is this located in? Also, how does one stop or prevent something like this?
> I'm part of a research team studying something similar. However, my role is minor but it is very interesting.


I'm not sure what caused it. Notice the anchors at the top? There's a possibility that they were not installed correctly/as-designed. A rock butress was installed after the initial slide (seen just below the failed road at the top). Then the slope below the butress failed. This is located in the northern mid-west (I don't want to get too specific, as it is in litigation). My role in this project is nil, except that the guy used the inclinometer from my office.


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## MGX (Apr 9, 2010)

I didn't expect you to get too specific. 

One of the girls leading the team is from Colombia where landslides are common. We're looking at using geo fabrics and geo grids to contain potential slide zones. I figured to shotcrete the whole works (lazy) but that's not always an option I'm told due to water buildup and some people have a problem with the looks.


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## FLBuff PE (Apr 9, 2010)

MGX said:


> I didn't expect you to get too specific.
> One of the girls leading the team is from Colombia where landslides are common. We're looking at using geo fabrics and geo grids to contain potential slide zones. I figured to shotcrete the whole works (lazy) but that's not always an option I'm told due to water buildup and some people have a problem with the looks.


We just analyzed a failure in Colorado where the shotcrete face of a soil nail wall failed. Shotcreting is not necessarily the answer! Pics related.


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## cement (Apr 11, 2010)

shotcrete, soil nails and rebar need to work together to make an effective ground nail wall. that way if one nail fais, the others can bridge the loading. and the nails need to be deeper than the failure plain for global stability.

that top picture, with a heavy duty tieback application ontop of a light duty rock buttress is pretty interesting. glad I didn't build it!

then that lower picture looks like just one row of soil nails? pretty skimpy if that's the case. and i can't see it, but you need to put drainboard behind a shotcrete wall to relieve the hydrostatic pressure.

some builders shop engineers to find the cheapest solution they will stamp. that's a dangerous game.

MGX, if you want to see an interesting slide, try googling Slumgullion Pass or Slumgullion Earthflow


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## FLBuff PE (Apr 12, 2010)

cement said:


> shotcrete, soil nails and rebar need to work together to make an effective ground nail wall. that way if one nail fais, the others can bridge the loading. and the nails need to be deeper than the failure plain for global stability.
> ...
> 
> some builders shop engineers to find the cheapest solution they will stamp. that's a dangerous game.
> ...


Ding ding ding...we have a winner!

We were set to design it, then got underbid. You get what you pay for.


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