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Hunter/Jumper
Member
+117|5404
I am building a pool behind my house which sits on a hill of solid rock.

         There is a section of Rock were if we cast a concrete bulkhead it will dam off a sizable amount of water
         and allow entry by walking down a smooth Rock surface.

What I am looking for is any concrete formulas which will tell me the thickness we need to use told hold back (X) height of water. I can Eyeball and make what I think would be a safe cast but since the Wall will contain filter lines and electrical conduits I want to know what the minimum should be. The concrete guys are balking as it seems to be something they haven't actually done without back filling behind the wall or using Gunite. They mostly pour cast foundations. I have text books with formulas on how to calculate water pressure as a function of height.  It seems to me there should be a simple formula for the Thickness of concrete needed but I can not come across one. The only Bulkheads I have seen cast were for seawalls and back filled with tamped soil. Not quite the same.  Any body come across this problem ?

Thanks in advance for any help.
UnkleRukus
That Guy
+236|4086|Massachusetts, USA
I really wanna know what goes through your mind when you make paragraphs and such.
If the women don't find ya handsome. They should at least find ya handy.
ghettoperson
Member
+1,943|5699

Pictures? I'm trying to visualise this. TBH it will depend on the type/thickness of the rocks/gravel in the concrete, and whether you decide to re-enforce it with steel bars, so I wouldn't think there is one specific formula. What I can tell you as a fact is, at a friends house he has a pool which is elevated and comes out from the slope the house is built on, so it's entirely held together by the strength of the concrete. I'd estimate the concrete walls to be half a foot thick. It could be re-enforced though, I don't know.
mtb0minime
minimember
+2,418|5705

I've got a response prepared but you need to post more details. What are you trying to accomplish? What exactly are you building? How much water are you trying to hold back? ("X" does not suffice; this is practice, not theory). (Reminds me of the guy who came on asking for instructions on how to hack facebooks and trace IPs and what the best keyloggers are because he wants to 'protect his children' = spy on girlfriend).


And since I know you're so concerned with people's resumes... I graduated from UCLA with a degree in Civil Engineering, the courses of which included a design course on concrete with re-bar (yes, there's a specific class entirely devoted to that), a structural design and testing laboratory, and an earth dam design course.

Am I professionally licensed and qualified to endorse your project? Absolutely not. Don't sue me if your shit breaks.

Last edited by mtb0minime (2010-09-22 17:03:43)

Home
Section.80
+447|5898|Seattle, Washington, USA

damn son, mtb now owns this thread
rdx-fx
...
+955|5641
Just call in a pool contractor. He, in turn, will call in the proper licensed help he needs to build on your particular site. 
Make them do the engineering calculations.

Trying to save a few dollars by guestimating where to put the concrete, to hold back a few thousand gallons of water, uphill from your house
Not the best tactic.

Holding back the water is easy.

Anchoring the wall properly, building it so it doesn't crack under load, and making it look halfway decent... that's the hard bit.

If you're in the design process anywhere where there should be a licensed contractor, you are screwed if that pool fails and dumps 20,000 gallons of water into your living room.
Jay
Bork! Bork! Bork!
+2,003|4408|London, England

rdx-fx wrote:

Just call in a pool contractor. He, in turn, will call in the proper licensed help he needs to build on your particular site. 
Make them do the engineering calculations.

Trying to save a few dollars by guestimating where to put the concrete, to hold back a few thousand gallons of water, uphill from your house
Not the best tactic.

Holding back the water is easy.

Anchoring the wall properly, building it so it doesn't crack under load, and making it look halfway decent... that's the hard bit.

If you're in the design process anywhere where there should be a licensed contractor, you are screwed if that pool fails and dumps 20,000 gallons of water into your living room.
Why you gotta spoil the fun? It would be a fantastic story if he just set the concrete on top of the stone and called it good
"Ah, you miserable creatures! You who think that you are so great! You who judge humanity to be so small! You who wish to reform everything! Why don't you reform yourselves? That task would be sufficient enough."
-Frederick Bastiat
ghettoperson
Member
+1,943|5699

RDX makes a good point, unless you have a lot of experience in the construction industry there's a pretty good chance you're not going to anchor the wall in properly.
rdx-fx
...
+955|5641

[email protected] wrote:

Why you gotta spoil the fun? It would be a fantastic story if he just set the concrete on top of the stone and called it good
Sorry.  Old Army engineer habit.  Have the reflexive twitch to yell "Hold! Cease fire!" when someone's about to do something that could get innocent bystanders injured.
Jay
Bork! Bork! Bork!
+2,003|4408|London, England
Because rdx brings up the point that your neighbors kids might end up dead because of your shoddy workmanship, I'll give you a real answer. If this is as I am visualizing it in my head, and you're planning a retaining wall to hold back water, you not only need to brace it correctly, you're more than likely going to have to drive piles into the bedrock as well. Bracing protects it from toppling, piling protects the bottom from sliding out. This is not a project that you want to DIY.
"Ah, you miserable creatures! You who think that you are so great! You who judge humanity to be so small! You who wish to reform everything! Why don't you reform yourselves? That task would be sufficient enough."
-Frederick Bastiat
Roger Lesboules
Ah ben tabarnak!
+316|5627|Abitibi-Temiscamingue. Qu├ębec!

[email protected] wrote:

Because rdx brings up the point that your neighbors kids might end up dead because of your shoddy workmanship, I'll give you a real answer. If this is as I am visualizing it in my head, and you're planning a retaining wall to hold back water, you not only need to brace it correctly, you're more than likely going to have to drive piles into the bedrock as well. Bracing protects it from toppling, piling protects the bottom from sliding out. This is not a project that you want to DIY.
Indeed, if we picture the same thing....you really want to have someone used to do that kind of work do it.
Dilbert_X
The X stands for
+1,746|5156|eXtreme to the maX
The strength to hold back water is the least of the problems.
Anchoring it, bracing it and sealing it are all much bigger. You can't necessarily just fix concrete to rock.
If you're burying other stuff in the concrete its much more complex again.

There are so many variables, so many critical details, you're not likely to find a substitute for getting a competent engineer on site to assess the situation and devise a solution - an engineer, not a contractor who thinks he is.

Then you need someone competent to build it to specification.
#FreeBritney
-Whiteroom-
Pineapplewhat
+572|5709|BC, Canada
working on the assumption that you already knew a gaming forum was not the proper place to ask a serious engineering question, what is the point of the thread? Also, if you felt that this was the proper place to be asking such questions, you really need to put down any tool you pick up.

Edit: also, in the EE section, instead of the serious talk section.

Edit Edit: Oh wait, I get it, this is connected to your Post your Resumes thread: You came here to search out people to help you with your DIY projects, and wanted to know our skill sets.

Last edited by Nic (2010-09-22 18:57:35)

Hunter/Jumper
Member
+117|5404

Dilbert_X wrote:

The strength to hold back water is the least of the problems.

Anchoring it, bracing it and sealing it are all much bigger. You can't necessarily just fix concrete to rock..
I have a rock drill and we are drilling into the rock for the Re bar.

Dilbert_X wrote:

If you're burying other stuff in the concrete its much more complex again.

There are so many variables, so many critical details, .
Have it down to bare rock so far. There is a Natural depression so the bulkhead will only be about 3 to 4 feet high max and only about six feet long.

Dilbert_X wrote:

you're not likely to find a substitute for getting a competent engineer on site to assess the situation and devise a solution - an engineer, not a contractor who thinks he is..
Thanks I have A guy who's gonna come up from the city but I wanted to have a basic plan to show him what I expected and wanted to do. If it could be done. The Basic plan meets the Zoning laws, I was a draftsmen at one point so I am pretty good with plans and prints. I had worked a lot of construction during college. I think its very " do-able "

Dilbert_X wrote:

Then you need someone competent to build it to specification.
This much I knew. I have Lot's people lined up, they have the equipment just never used it in quite this fashion, The pool people wanted to sell me an existing design ( one of ten that they crank out ) none were suitable or esthetically pleasing to  the eye.
So far Thanks,
Hunter/Jumper
Member
+117|5404

Nic wrote:

working on the assumption that you already knew a gaming forum was not the proper place to ask a serious engineering question, what is the point of the thread? Also, if you felt that this was the proper place to be asking such questions, you really need to put down any tool you pick up.

Edit: also, in the EE section, instead of the serious talk section.

Edit Edit: Oh wait, I get it, this is connected to your Post your Resumes thread: You came here to search out people to help you with your DIY projects, and wanted to know our skill sets.
Just asked for a formula, Don't even think we need one, just thought one might exist. When I heated my indoor ring I used a formula that showed me it would be quite feasible and it worked out well.
Hunter/Jumper
Member
+117|5404

[email protected] wrote:

Because rdx brings up the point that your neighbors.
I don't have any, I own a bit of property, A stream is down hill of my house that leads into a small lake. Worst case (* or Funniest ) The lake would rise a few inches and my driveway would be wet. We are not talking a Lap pool. Just a visual enhancement that you can cool off in and Some man made water falls. If it was 2 feet shallower in the deep part it wouldn't need a building permit.

[email protected] wrote:

kids might end up dead because of your shoddy workmanship,
My workmanship is not shoddy.

[email protected] wrote:

I'll give you a real answer. .
please do !


[email protected] wrote:

If this is as I am visualizing it in my head, .
Scary and lotsa room I bet. lol ! Sorry !


[email protected] wrote:

and you're planning a retaining wall to hold back water, you not only need to brace it correctly,.
yes


[email protected] wrote:

you're more than likely going to have to drive piles into the bedrock as well..
yes


[email protected] wrote:

Bracing protects it from toppling, piling protects the bottom from sliding out. .
yes


[email protected] wrote:

This is not a project that you want to DIY.
No its just my idea. I am throwing the money at it but I want some basic knowledge of the physical mechanics involved.

The one Engineer who was up here for an Xmas party seemed to think it was a go. But he lives a ways off and is retired.

I don't wanna hassle him. Thanks so far

* sorry about those  troublesome Italics
Hunter/Jumper
Member
+117|5404

UnkleRukus wrote:

I really wanna know what goes through your mind when you make paragraphs and such.
Something tells me this wont be anything on your to do list soon, Am I correct ? We don't have the same problems do we ?
Hunter/Jumper
Member
+117|5404

mtb0minime wrote:

I've got a response prepared but you need to post more details. What are you trying to accomplish? What exactly are you building? How much water are you trying to hold back? ("X" does not suffice; this is practice, not theory). (Reminds me of the guy who came on asking for instructions on how to hack facebooks and trace IPs and what the best keyloggers are because he wants to 'protect his children' = spy on girlfriend).


And since I know you're so concerned with people's resumes... I graduated from UCLA with a degree in Civil Engineering, the courses of which included a design course on concrete with re-bar (yes, there's a specific class entirely devoted to that), a structural design and testing laboratory, and an earth dam design course.

Am I professionally licensed and qualified to endorse your project? Absolutely not. Don't sue me if your shit breaks.
I wont n thanks !
13urnzz
Banned
+5,830|5547

c-c-c-c-combo breaker!
Hunter/Jumper
Member
+117|5404
I have run all kinds of equipment and even some pretty huge stuff for the RR way back. I have an Articulated Loader and a track Hoe now and they are intimidating to me. It takes me an hour or so before I feel comfortable. I am aware of the scope of this project. When its done I will try and post a pic or two. Right now I'm still Clearing. If I knock some thing over or flatten a car I will keep everyone posted because I know that's what you Want to hear.
" It's always funny till  some one gets hurt and then its F-n hilarious "
Dilbert_X
The X stands for
+1,746|5156|eXtreme to the maX

Hunter/Jumper wrote:

Dilbert_X wrote:

you're not likely to find a substitute for getting a competent engineer on site to assess the situation and devise a solution - an engineer, not a contractor who thinks he is..
Thanks I have A guy who's gonna come up from the city but I wanted to have a basic plan to show him what I expected and wanted to do. If it could be done. The Basic plan meets the Zoning laws, I was a draftsmen at one point so I am pretty good with plans and prints. I had worked a lot of construction during college. I think its very " do-able "

Dilbert_X wrote:

Then you need someone competent to build it to specification.
This much I knew. I have Lot's people lined up, they have the equipment just never used it in quite this fashion, The pool people wanted to sell me an existing design ( one of ten that they crank out ) none were suitable or esthetically pleasing to  the eye.
So far Thanks,
Just get a proper specification from your city guy, don't deviate from it, you should be OK.
How are you fixing the rebar to the rock?

Over-engineering in civil is usually the cheapest option, its just material cost really - provided you're sure any changes you make really are strengthening the design.

Last edited by Dilbert_X (2010-09-22 21:09:27)

#FreeBritney
UnkleRukus
That Guy
+236|4086|Massachusetts, USA

Hunter/Jumper wrote:

UnkleRukus wrote:

I really wanna know what goes through your mind when you make paragraphs and such.
Something tells me this wont be anything on your to do list soon, Am I correct ? We don't have the same problems do we ?
Something tells me you're a dumb twat, probably as dumb as pace51.
If the women don't find ya handsome. They should at least find ya handy.
PrivateVendetta
I DEMAND XMAS THEME
+704|5241|Roma
Where did this guy come from all of a sudden anyway posting in EE?
Been hiding in D&ST or has he just come out of the woodwork to troll with 'serious questions'?
https://static.bf2s.com/files/user/29388/stopped%20scrolling%21.png
krazed
Admiral of the Bathtub
+619|5830|Great Brown North
D&ST trawler captain
Hunter/Jumper
Member
+117|5404

Dilbert_X wrote:

Hunter/Jumper wrote:

Dilbert_X wrote:

you're not likely to find a substitute for getting a competent engineer on site to assess the situation and devise a solution - an engineer, not a contractor who thinks he is..
Thanks I have A guy who's gonna come up from the city but I wanted to have a basic plan to show him what I expected and wanted to do. If it could be done. The Basic plan meets the Zoning laws, I was a draftsmen at one point so I am pretty good with plans and prints. I had worked a lot of construction during college. I think its very " do-able "

Dilbert_X wrote:

Then you need someone competent to build it to specification.
This much I knew. I have Lot's people lined up, they have the equipment just never used it in quite this fashion, The pool people wanted to sell me an existing design ( one of ten that they crank out ) none were suitable or esthetically pleasing to  the eye.
So far Thanks,
Just get a proper specification from your city guy, don't deviate from it, you should be OK.
How are you fixing the rebar to the rock?

Over-engineering in civil is usually the cheapest option, its just material cost really - provided you're sure any changes you make really are strengthening the design.
Thanks !
I am not doing the ReBar but I'll ask him. Out of curiosity. I always saw them tie Re bar together with heavy wire spot welded.  How do they Ground that Green plastic covered Re Bar ? also is The Green Re Bar falling out of Favor ? I don't see it on big jobs anymore ? The new Stuff looks like SS or Aluminum ?

Last edited by Hunter/Jumper (2010-09-23 05:07:39)

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