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
http://www.americancontractingllc.com/plans/ "US CORPS CHATFIELD DAM SUBDRAIAGE"An extensive system of sub-drainage and collector pipes (over 21,000 feet) exist beneath the approach slab, the ogee weir, the chute slab and stilling basin and behind the chute walls.
The pipes range in diameter from 3 to 12 inches. Pipe material types include solid and perforated PVC, solid and perforated vitrified clay pipe, solid asbestos cement pipe and perforated CMP. 1.3
Objectives: The overall objective of this contract is to thoroughly document the current condition of the sub-surface drains and collector pipes of the spillway structure. 1.4
Scope: Work generally consists of visual inspecting the drainage pipe (both vertical and horizontal) with remote-operated camera equipment and producing a detailed formal report to thoroughly document the condition of these features. To enable visual inspection of the vertical chute slab foundation drains (18 total), mechanical cleaning (brushing and flushing with water) will be required for these pipes. Deliverables from this work will include DVD(s) of the inspection footage and a report that summarizes the procedures and findings of all inspections and includes individual inspection logs that summarizes the condition each pipe segment and documents the location of any significant observation.
The Contractor shall perform these services as noted in this PWS. All work shall be conducted in accordance with current professional standards, Corps of Engineers policies, regulations, and procedures. The Contractor is responsible for supplying all equipment, supplies, materials and personnel necessary for the completion of this work. 1.5 Scope Period of Performance: The period of performance for the PWS shall be
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.