17 foot High Block Wall?

[aztecaa]

I have a lot that is on the side of the hill.
I have excavated and cut into the hill.
It is about 17 feet high at the back.
At the bottom of where I plan to pour cement onto a rock bed compacted down into the dirt trench. (lots of rock in the hill and floor)

WILL... 15X20X40cm cinder blocks with rebar every 40cm (cement Fill cores) apart and (rebar/rings wired) pilaster erected every 6-7 feet apart and another (rebar/ring wired) horizontal joint reinforcement every 5 feet high.(will back fill also)
An L at each end approximately 12' end to end.
A 2' wide rebar footings every 40 cm wired to horizontal (rebar/rings wired), laid on a level, compacted CEMENT base 8"X4" (cement form) to set the first level of blocks on.
Suffient enough to hold the dirt back?

Also ...WHERE or how high do I set the perforated 4" Tube behind the the block retaining wall?

 

[stuart45]

Your Building Regs are different to ours because of your earthquake problem. Are you using 8 or 12 inch blocks? What part of California is it?

 

[aztecaa]

15X20X40 cm r the blocks I am using. I believe US would be 6X8X16 to be exact 5.9X7.9X15.7
Also the blocks r high strength.
Actually it is a vacation home project in Baja near the ocean.

 

[Norcon]

I would say forget about blocks and use reinforced concrete. A retaining wall shuttered with concrete the height of a bank that size will be in the region of 450mm wide double reinforced. The pressure behind will be collossal.
3/4" on the bank side spaced every 200mm and 5/8" starter bars on the front with matching spacing and 4' in height.
The bank side will have finishing 3/4" bars the full height with 5/8 horizontal runs spaced at 300mm centers.
The front can be finished with 10mm mesh the full height also.
Cost you about £500 per meter.
Look something like this when its finished......... real purdy innit?
You can waste a few grand on a SE or employ a firm like us and we will use our own spec.
Ain't had a collapse yet! Though we don't have earthquakes here in the UK.
We have our own Peri shuttering to do this so it aint a problem though crossing the pond might be so I would say find someone local and dig deep into the ole pockets.

 

[aztecaa]

I have 500 blocks, 40 - 3/8" rebar sitting on the lot!
That wall in the photo is about 40' high.
But I understand what your saying.

 

[stuart45]

I not an SE but I would not think that the wall you are building will be thick enough to hold that amount of earth back, even with reinforcment.

 

[Norcon]

aztecaa wrote

A 2' wide rebar footings

We would be making the foundation for this about 3m wide. 400mm deep, double reinforced also. The excavation for the foundaton would leave an abutment against hard till to act against the push effect of the structure caused by the huge pressure of the backfill.

 

[Shytalkz]

And I bet you your base will be insufficient to resist sliding.

 

[noseall]

Secant bored pile walls may be cheaper, but would require finishing.

 

[Norcon]

 

[aztecaa]

Secant bored pile walls may be cheaper, but would require finishing.

Can you show me a picture of what one looks like.
Thanks

 

[noseall]

Secant bored pile walls may be cheaper, but would require finishing.

Can you show me a picture of what one looks like.
Thanks

 

[stuart45]

Blockwork will look better. If you see a photo you will know what I mean. You probably need to lay the blocks to form a 16 inch thick wall. Did you buy the blocks in Tijuana?

 

[aztecaa]

Blockwork will look better. If you see a photo you will know what I mean. You probably need to lay the blocks to form a 16 inch thick wall. Did you buy the blocks in Tijuana?

They were bought about an hour further south from a company who blasts mountains there and makes these blocks from the granite, rock.

 

[aztecaa]

The Secant bored pile walls are going to cost more after calculating! But thanks for the option.