 |
Re: Oroville Dam,
Author: Ed Workman
Date: 02-14-2017 - 11:37
Well Harris- are you a enguneer?
I wonder how a level waterway would work?????
I myself took and passed the plumber test:
Hot on the left, Cold on the right, and S*** runs downhill.
The spectacular videos are of the regular spillway.
First use was 1969.
A spillway inlet is just below the top of a dam, so it starts flowing before the water gets to the top of the dam. Nobody has to remember to check a valve in the middle of the nite , it just works, tuhhDAAAAA
There was a 5.7 quake just south of Oroville in 1975. EVERYTHING was inspected, measured etc. The only damage to the spillway was some bumping against the inlet- not enough to even cost out or fix. There was a little settlement/consolidation in the dam itself.
Then there is an emergency spillway- it's not the one in the videos.
It's intake is well below the top of the dam and the regular spillway intake,
that's the reason there is no water now in the regular spillway and folks are walking around and dumping rock- The emergency spillway is 50 ft or more below the regular one [IF one believes the news]
The news doesn't get it, and uses the two things interchangeably- veerrrrry helpful.
As to cracks in the concrete- Concrete is made with water. The water that isn't chemically combined with the cement, to glue the aggregate together, evaporates in time.
The spaces left cause shrinkage, and shrinkage causes cracks- not Micro cracks, visible cracks. Avoiding cracking in anything larger than about 6x6 feet is just about impossible.
About the time the spillway was built a prof at UC Berkeley was investigating/inventing shrinkage compensating cement. I doubt very much that the DWR used it in its infancy, but WHo KNows. The dam itself has drains. The water that squeezes thru the pores in the clay core was around 90 gal/minute. I can't say how much water flowed thru cracks in the spillway- but in any particular area it had to be much less. COncrete with SCC actually shrinks, THEN expands.
Reinforcing in concrete must strain to work. Strain means stretch [in this case],
concrete does that poorly, so to make the reinforcing effective, concrete must crack.
Now if one adds a LOT of rebar, the cracks, due to shrinkage and other strains,
can be reduced in width and crack spacing decreased.
AND the news cites some enviroturds that said "told you so". I am loathe to spend time chasing down what they said, but I doubt very much that their prophecy holds water
[ yes I wrote that on purpose]
So if they paid me The BigBucks to figure out What Happened Mr. Smarty Pants, what would I do?
I'd somehow get aholt of the earliest recent videos of the working spillway and see if the water overtopped the chute wall, eroding the support- I probly should compare the previous flows before doing that hard work- Did this outflow exceed by a significant amount the outflows of 1969, 1979 and any others?
Anyone want a lesson on soil compaction?
I wonder how a level waterway would work?????
I myself took and passed the plumber test:
Hot on the left, Cold on the right, and S*** runs downhill.
The spectacular videos are of the regular spillway.
First use was 1969.
A spillway inlet is just below the top of a dam, so it starts flowing before the water gets to the top of the dam. Nobody has to remember to check a valve in the middle of the nite , it just works, tuhhDAAAAA
There was a 5.7 quake just south of Oroville in 1975. EVERYTHING was inspected, measured etc. The only damage to the spillway was some bumping against the inlet- not enough to even cost out or fix. There was a little settlement/consolidation in the dam itself.
Then there is an emergency spillway- it's not the one in the videos.
It's intake is well below the top of the dam and the regular spillway intake,
that's the reason there is no water now in the regular spillway and folks are walking around and dumping rock- The emergency spillway is 50 ft or more below the regular one [IF one believes the news]
The news doesn't get it, and uses the two things interchangeably- veerrrrry helpful.
As to cracks in the concrete- Concrete is made with water. The water that isn't chemically combined with the cement, to glue the aggregate together, evaporates in time.
The spaces left cause shrinkage, and shrinkage causes cracks- not Micro cracks, visible cracks. Avoiding cracking in anything larger than about 6x6 feet is just about impossible.
About the time the spillway was built a prof at UC Berkeley was investigating/inventing shrinkage compensating cement. I doubt very much that the DWR used it in its infancy, but WHo KNows. The dam itself has drains. The water that squeezes thru the pores in the clay core was around 90 gal/minute. I can't say how much water flowed thru cracks in the spillway- but in any particular area it had to be much less. COncrete with SCC actually shrinks, THEN expands.
Reinforcing in concrete must strain to work. Strain means stretch [in this case],
concrete does that poorly, so to make the reinforcing effective, concrete must crack.
Now if one adds a LOT of rebar, the cracks, due to shrinkage and other strains,
can be reduced in width and crack spacing decreased.
AND the news cites some enviroturds that said "told you so". I am loathe to spend time chasing down what they said, but I doubt very much that their prophecy holds water
[ yes I wrote that on purpose]
So if they paid me The BigBucks to figure out What Happened Mr. Smarty Pants, what would I do?
I'd somehow get aholt of the earliest recent videos of the working spillway and see if the water overtopped the chute wall, eroding the support- I probly should compare the previous flows before doing that hard work- Did this outflow exceed by a significant amount the outflows of 1969, 1979 and any others?
Anyone want a lesson on soil compaction?
