Retaining Wall

[cypriotxx]

what would be the specs drawing or details for 2.5m high and 5m long retaining wall with hollow concrete blocks ?

i have found this online but this is for much less height ..
http://www.diynot.com/diy/media/untitled.57650/full?d=1362404801

 

[russellsmiler]

A retaing wall of 2500mm ideally needs the input of a structural engineer, the ultimate design depends on its retaining situation and ground conditions.
the link and spec shown would not be suitable for a 2500mm high wall, that is assuming you are asking it to retain to its full height!!
if its fully retaining 2500mm of earth behind it, with hydrostatic pressure a cosideration then a solid in situ placed reinforced concrete wall and base would most probably be the preferred solution, remember the interlinked base playes a big part in the walls potential to roll over, again there may be ground conditions were the wall would potentially slip forward on the base and thus a "root" or toe needs to be incorporated below the wall, either directly or at the end of the base.

If you can give a good description of what you are trying to retain i could probably pull together a good solution, however theres no short cuts to a suitable retaing wall, all walls have some ability to retain... but in true essence a retaining wall can only be described as thus when it is retaining the loads in its specific location.

 

[noseall]

As above, I'd be inclined to seek some professional input on a retaining wall of that height.

 

[^woody^]

I've built them 9" with just some exmet in the bed joints.

I don't think that SE's need to be involved unless it's some extravagant situation.

But asking for "the specs" is a bit of a non starter. There are several site specific factors to consider.

 

[noseall]

I've built them 9" with just some exmet in the bed joints.

......and I've built them 9 inches without brick tor.

2.5m though Woodrack.....trés tall.

 

[^woody^]

..... only 300mm high measured from the back.

 

[themiddleagedun]

Just done one recently the same height as that (engineer designed) this was the make up:

100mm block, 160mm cavity, 140mm block.

It was built off a raft with starter bars in the cavity. One wall was built, mesh was then tied to the starter bars, and packed off, then the remaining wall built, and the cavity was filled with conc.. the 100mm block was too thin IMO.

 

[RonnyRaygun]

Just done one recently the same height as that (engineer designed) this was the make up:

100mm block, 160mm cavity, 140mm block.

It was built off a raft with starter bars in the cavity. One wall was built, mesh was then tied to the starter bars, and packed off, then the remaining wall built, and the cavity was filled with conc.. the 100mm block was too thin IMO.

I take it the 100mm block was the back face of the wall? If so it's just acting as a formwork for the concrete so the thickness of the block is pretty much irrelevant.
The wall sounds about right for 2.5m depending on soil conditions, surcharge etc, but for the OP it's important to also ensure that the foundation is the correct width, thickness, and suitably reinforced.
For the wall the size and position of the rebar is also important.

 

[theprinceofdarkness]

When you build a retaining wall it can take decades for the wall to take up its final position, so any wall that is less then 5 years old cannot be taken as an example.
For instance, I built in 1985 a tiny earth retaining wall on 9" by 9" concrete foundation about 12" deep in clay, I then built a little single skin wall which stood up three bricks high along the edge of a path. The problem was the the other side of this wall had an earth bank about 4' high going back 4'. By 2000 the wall was intact but out of plumb by about an inch. I then moved house. I reckon that the whole thing just rotated.
Frank

 

[^woody^]

Lol. The wall should not move. That's the whole idea of it, to retain.

 

[RonnyRaygun]

When you build a retaining wall it can take decades for the wall to take up its final position, so any wall that is less then 5 years old cannot be taken as an example.
For instance, I built in 1985 a tiny earth retaining wall on 9" by 9" concrete foundation about 12" deep in clay, I then built a little single skin wall which stood up three bricks high along the edge of a path. The problem was the the other side of this wall had an earth bank about 4' high going back 4'. By 2000 the wall was intact but out of plumb by about an inch. I then moved house. I reckon that the whole thing just rotated.
Frank

If it's rotated it's either not been designed properly or has had additional forced applied (surcharge from vehicles, storage of materials etc) which shouldn't have been applied...

 

[themiddleagedun]

Just done one recently the same height as that (engineer designed) this was the make up:

100mm block, 160mm cavity, 140mm block.

It was built off a raft with starter bars in the cavity. One wall was built, mesh was then tied to the starter bars, and packed off, then the remaining wall built, and the cavity was filled with conc.. the 100mm block was too thin IMO.

I take it the 100mm block was the back face of the wall? If so it's just acting as a formwork for the concrete so the thickness of the block is pretty much irrelevant.
The wall sounds about right for 2.5m depending on soil conditions, surcharge etc, but for the OP it's important to also ensure that the foundation is the correct width, thickness, and suitably reinforced.
For the wall the size and position of the rebar is also important.

Yes the 100mm block was to the back face and acting mainly as formwork. The blocks cracked in a couple of places though, despite filling in two pours and being propped, where as the 140's never budged.