Still of likely drainage pipe, sheeting, and gravel under the spillway:
A better picture of that detail.
pg 172 of 193
Well, in fact, what is pictured does appear to be installed properly, as it appears to be nearly exactly as the design document (HYD-510.pdf) called for (excepting that the drainage was upsized to 6"). If you are actually suggesting that it wasn't designed properly, your collateral also doesn't support that conclusion for at least two reasons:Deirdre ~~~
My post above was removed,.Evidence is now provided and the installed VCP installed in the spillway was not installed properly.
what does that have to do with drains?I post this here as it relates to the underlaying conditions upon which the spillway is built. I couldn't figure out how to post a hi-res version of that image here, nor how to insert colored arrows to mark precisely this transition.
no it won't. which is why using the MB reply functions and tags is important to conversation.It appears my comment is in the quote box and might be mistaken for your content
Also, note the collection drains.
This picture has provided me with some great information about the arrangement and operation of the drains:
You can see in the photo 2 of the lateral drains exiting under the sidewall grade-beam - I surmise that the longitudinal drain here is missing due to damage - it likely exists upstream under the debris as noted.
This view and the one directly above, in post #177, appear to show a line on the outside of the sidewall from the drain tile in the backfill to the fitting through the wall. I am guessing it is a construction line to show the level of backfill prior to placing the connecting pipe to the wall drain.
Could the angle between that line and the top of the wall be determined to see if it resembles the angle that the spillway decends the hillside?
The "pencil line" on the wall between the pipe in the fill and the elbow on the wall is almost exactly parallel to my estimate of hoizontal.
... I would say that the mismatch between the "pencil line" and your line could easily describe the necessary slope for the pipe to get the water to the wall drain properly. I believe you have shown that the "pencil line" is actually a guide line for the original construction crew as they placed the backfill for the pipe to rest on when it was installed. ...
It also looks like an extension of your line would intersect the vertical pipe farther upslope about at the bottom of the spillway. Very nice work.
The drawings in the CA State Water Project report
appear to indicate the longitudinal drains run in the exterior corner between the wall and slab.
Not only this! If there's a continuous downhill collector, inner pressure will eject water in all directions beneath the actual water level, both into the outlets and into the intakes (perforated sections). The water will flood the under-slab space, and at some lower elevation it will act as a water-jetting device.As mentioned earlier in this thread, a continuous downhill collector run would allow very large pressures to develop, something the clay pipe is not so great at dealing with.
"Estimated horizontal" appears off. Based on the photo (post # 180 Orville Dam Drains Thread ) of the scaffolding in the spillway, assuming the scaffolding is vertical , true horizontal diverges from spillway top at ~ 15 degrees (+ - 2 degrees). The "estimated horizontal" diverges from the spillway top at ~ 30 degrees (+ - 5 degrees). Based on this the estimated horizontal is rising ~ 15 degrees towards the downstream.Slope of the spillway ... applicable to the top of the sidewall, to preclude the need to estimate the horizontal in post#180.
Anyway, these pipes don't seem to fit with each other.
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