Roads damaged in natural disasters

[hm insulators]

Here are some photos of damaged roads caused by a 6.0 quake that struck the S.F. Bay Area (Napa/American Canyon to be exact) Sunday morning...

What's that they say about life giving you lemons, making lemonade?

[Brian556]

The Portuguese Bend Landslide on the south side of the Palos Verdes Peninsula near L.A. is a long-term disaster. Construction to extend Crenshaw Blvd. down the south side of the hills in the mid-1950s started a large area moving, eventually destroying a number of homes. Palos Verdes Drive South crosses this area, and at least when I was living in that area was continually rebuilt. The water main runs above ground along the road to avoid breakage. I'm not sure what the current status of this area is, but I have to think the slide is of very long duration.

The ground is very unstable there and they have to constantly repair that road. That section is announced by signs that read along the lines of "CONSTANT EARTH MOVEMENT NEXT 2 MILES". I drove it as recently as last Christmas.

US 41/64/72 west of Chattanooga, TN is like that. The section that runs along the TN river is constantly trying to slide into the river. It requires constant repairs. I think the only reason they routed the road this way was to keep it in TN; and not have it dip into GA like I-24 does.

In the early days, there appears to have been 3 routes between Chattanooga and Jasper; none of which took this route.

[SteveG1988]

http://www.nj.com/news/index.ssf/2011/08/portion_of_interstate_287_coll.html

[DaBigE]

The County Hwy A washout when Lake Delton drained after heavy rains in June 2008 (Sauk County, WI):

Source: Madison.com

before/after photos from the recovery

[Bruce]

Here's WA-530, cleared in May after the Oso mudslide in March:


SR 530 clearing - May 30, 2014 by WSDOT, on Flickr


SR 530 clearing - May 30, 2014 by WSDOT, on Flickr

[triplemultiplex]

Mongollon, New Mexico in November 2013 about two months after a catastrophic flash flood.  NM 159 was utterly removed in places.  A crude path made with a bulldozer provided access at the time I was there.


That's a cross-section of the road on the right.  Of note are the layers of older flood debris beneath the road bed.

[sdmichael]

The Portuguese Bend Landslide on the south side of the Palos Verdes Peninsula near L.A. is a long-term disaster. Construction to extend Crenshaw Blvd. down the south side of the hills in the mid-1950s started a large area moving, eventually destroying a number of homes. Palos Verdes Drive South crosses this area, and at least when I was living in that area was continually rebuilt. The water main runs above ground along the road to avoid breakage. I'm not sure what the current status of this area is, but I have to think the slide is of very long duration.

The ground is very unstable there and they have to constantly repair that road. That section is announced by signs that read along the lines of "CONSTANT EARTH MOVEMENT NEXT 2 MILES". I drove it as recently as last Christmas.

When I'm driving, I don't want my earth to move, I want it to stay put, thank you.

Looks like this:

http://socalregion.com/geology/los-angeles-geology/landslides/

[myosh_tino]

0.8 miles?!? 

Decimal distances are pretty rare in California (except on construction signs).  I would have use "3/4" instead.

Also, going back to the Napa quake, it was reported yesterday on the news that apparently the aftershocks (some as large as M3.6) are still doing damage to CA-29.

[sdmichael]

Also, going back to the Napa quake, it was reported yesterday on the news that apparently the aftershocks (some as large as M3.6) are still doing damage to CA-29.

Considering the geology, I'd expect as much. That area is either recent alluvium, unconsolidated bay/marsh deposits, or deltiac deposits. It also has a high water table. Settlement can and does occur. Thankfully, the quake wasn't a 7+ on the Hayward, which has the potential to cause parts of the San Joaquin / Sacramento Delta levees to collapse.