*1994 Northridge
Same section of the CA-14 collapsed. Made famous in 1971 by the Doobie Brothers.
Overmod When the Little Friskies built the elevated section of 880, Caltrans required that the deck slabs be retained by transverse chains, as was then standard 'revealed wisdom' in their seismic design.
When the Little Friskies built the elevated section of 880, Caltrans required that the deck slabs be retained by transverse chains, as was then standard 'revealed wisdom' in their seismic design.
FWIW, that section of freeway was called CA-17 when built, renamed to I-880 not too long before the Loma Prieta quake hit. That section earned a mention in the concrete portion of my E45 (intro to Engineering Materials at Cal) as what happens when the forms for the concrete are removed before the concrete is sufficiently cured. The prof said that it was a good stretch of road for testing shock absobers... A similar problem happened with NCTD/CalTrans building a new bridge over the Santa Margarita river at the southwest corner of Camp Pendleton - bridge had to be rebuilt die to forms being removed too quickly.
Good thing there was a baseball game going on - I remember seeing the live aerial images of that freeway a few minutes after the quake and shuddering from assuming that the freeway was loaded with cars.
The REAL problem with the CA-17/I-880 elevated section and other reinforced concrete structures was lack of "hoop" strength in the bridge columns. The shaking would break the concrete and the inadequate circumferential reinforcing would allow the concrete to crumble and fall out. This then led to the bridge columns collapsing. One retrofit was to wrap the columns with steel casings or arbon fiber pre-preg. The problem was made painfully known with the collapse of bridges during the 1971 Sylmar quake, which led to changing how bridge columns were made (a LOT more circumferential reinforcement). The 1989 Loma Prieta quake showed that the pre-71 bridges needed to be reinforced and the 1974 1994 Northridge quake showed that the retrofitting needed to be speeded up.
N.B. For some imformative analysis of the Surfside Condo collapse, check out the "Building Integrity" channel on You Tube. The presenter goes into detail about failure modes for reinforced concrete structures.
ronrunner HART IN HAWAII COMES TO MIND IN A CITY THAT IS BUILT ON A ACTIVE VOLCANO WITH EARTHQUKES SO THEY BUILD A ALL EL SYSTEM
HART IN HAWAII COMES TO MIND IN A CITY THAT IS BUILT ON A ACTIVE VOLCANO WITH EARTHQUKES SO THEY BUILD A ALL EL SYSTEM
The closest active volcano to Honolulu is on the far side of the Island of Maui.
"little friskies?" Say what?
Oh, it gets much better than that. When the Little Friskies built the elevated section of 880, Caltrans required that the deck slabs be retained by transverse chains, as was then standard 'revealed wisdom' in their seismic design. When the earthquake came, the chains neatly sequentially jerked the slabs off the supports to fall on victims on the lower deck. There were some unforgettable horrors from that rather predictable design abortion.
The locks on the Ten-Tom canal limit the size of the barge tow, vs. the lower Mississippi. A port with river-ocean transfer will always be needed near the mouth of the Mississippi.
Gramp I agree regarding the Mississippi delta. The Mississippi created everything south of Cairo, Il. In my view, to attempt to control it from finding its new course to the Gulf (thus bypassing New Orleans) has been detrimental to the overall health of the delta.
I agree regarding the Mississippi delta. The Mississippi created everything south of Cairo, Il. In my view, to attempt to control it from finding its new course to the Gulf (thus bypassing New Orleans) has been detrimental to the overall health of the delta.
ronrunner As far as cities in addition to weather..we have seen the implications of stress of overcrowding on citizens and those who are responsible for governance which results in mental illness corruption and death by violence by police at wits end and youth who are locked our of the economy
As far as cities in addition to weather..we have seen the implications of stress of overcrowding on citizens and those who are responsible for governance which results in mental illness corruption and death by violence by police at wits end and youth who are locked our of the economy
What was that line in "Seven Days In May"? "He does sound a little overripe."
Rick
rixflix aka Captain Video. Blessed be Jean Shepherd and all His works!!! Hooray for 1939, the all time movie year!!! I took that ride on the Reading but my Baby caught the Katy and left me a mule to ride.
I still wonder if we might stumble on a way to desalinate from ocean water that is far more efficient than drilling wells or relying on rain storms and reservoirs. Though that would not be enough to dent rising sea levels much since we are in a closed system and you would have to find a way to remove the water from circulation vs stall it's flow back to the ocean.
As for rising sea levels, I think the models are rather draconian in their out years plus they suffer from the common forecasting trend error of assuming everything else will remain constant in the longer term out years. We have found with past envionmental models that is not always the case.
ronrunner NOLA comes to mind as well as LA..MEXICO CITY AND MIAMI
NOLA comes to mind as well as LA..MEXICO CITY AND MIAMI
Most of the city of L.A. is above 10'msl, so don't think there's much risk of flooding. Miami may be a different story with the subsidence adding to the problem of rising sea levels which has been running about 2 - 3mm/yr since the mid-1800's.
The SoCal rail line most threatened by sea level rise is the section of the AT&SF Surf line along the coast in San Clemente along with the bluffs supporting the Surf line in Del Mar.
Bringing this back to rail unless railroads adapt via building more short lines the mega one size fits all will not work. I see a future for hyperlink tubes not for people but for freight ,stuff and work will come to us at home we won't have to go to it
And then there's Paterson, and Detroit, and half the cities in the Rust Belt. What cities will do poorly with the upcoming changes?
We actually export more grain and beans then we consume..If we kept the food at home grocery prices would be less expensive ...Smaller more efficiant farms growing a variety of crops under a subscriber contract system will replace large monoculture factory farms. IT and computers will plan what and who needs what.The idea out there is to have micro contracts be traded on the Chicago and other Commdities Markets.We are already seeing a trend now with grass fed beef local food to fork programs.I want to go back to the days of small family and co-op farms and tech will bring us there. We have less people BTW as birth control and a series of pandemics and wars will push us into a reset...Look to the Amish for answers..
I guess every place high numbers of people are actually living are unsafe - so relocate them to flyover country to replace the wheat, corn and beans that inhabit that country. [/sarcasm]
Never too old to have a happy childhood!
NOLA makes no sense to me..how the French and Spanish made a city that is on a tidal mud flat and then expanded it by infill and the use of pumps and canals and tunnels that run 24 hours a day pumping out millions of gallons a day..MIAMI is built on a sand spit that any tall buildings like N0LA have to go deep to hit bedrock.MEXICO CITY is built on a old lake bed so no surprise that there EL collapsed. Chicago was built on a swamp and there been flooding of the tube system and the city that we see now is built on pilings of the old city pre fire. The freight tube system is the backbone of the fiber optics network for the region. San Fran and LA Sit on a fault line and SF is land locked. BOSTON is expanded by fill dating to 1700s and its sewage system is plagued with problems.Manhatten will be underwater in 100 years...Pheonix will run outta of way water and the baby busters after the baby boomers pass on will cause a real estate glut...My prediction is that city's like Montreal and Quebec will grow to warmer climate..Cleveland and Detroit will come back as Midwest hubs and a new megacity will sprout in Maine and Prince Rupert BC or mega city's will just go away in favor of small cluster towns in a virtual world that does not need anyone to commute
Before u poo on me for this there are plenty of anciant ancient city's underwater or buried by 50 feet of sand. What made sense to have a city then may not make sense now.NOLA comes to mind as well as LA..MEXICO CITY AND MIAMI
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