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Groundwork & Foundations Question
Just wondering if someone could advise on a retaining wall that would be a nip under 4ft and about 10m with a slight curve. This is to make a flat area to park on in the driveway.
I posted a job but haven't had any responses yet so was going to call a few professionals in my area and wanted a little guidance in advance to check what I am being offered is good enough.
Would this type of method suffice for what I am after http://www.readersdigest.com.au/retaining-wall?
Thanks for any help
It sounds as though the retaining wall will be required to hold some significant weight, with live loads from vehicles.
We would suggest a reinforced concrete gravity retaining wall (basically an L shaped cast in-situ unit, with L facing inwards to the car park) that runs the height/ length you require. The bottom of the L faces the high area of ground / car park, and stops the wall toppling outwards by virtue of the weight on itself, hence the name "gravity wall".
The outside face of the L shape acts as a solid wall to vertically retain the earth or fill material, and can then be hidden by a brickwork wall or other finish, or if its a utility or commercial property perhaps just left as concrete.
Sometimes these L shaped items can be bought pre-cast and installed on a level base of hardcore, then backfilled. This would likely be cheaper and quicker than forming the units on site.
The gravity wall is a very strong system with a design life of over 50 years.
There are other systems, such as inserting steel "i" beams into the ground and using railway sleepers in between, or extra thick brickwork filled with concrete, all on a deep foundation, but the concrete gravity system I described above is the most durable and cost effective in our experience.
Any queries, please let me know. Thanks
Answered 18th May 2012
4Ft is not a lot of earth to retain but I am not sure if the car is to be parked on the high side or the low side.
I would do as Blackat described but use solid 7N concrete blocks laid flat (9" wide) to form the retaining wall.
I would place a land drain behind the wall and a few weep holes at lower level to ease the pressure of water build up.
I would face the retaining wall with Brickwork for asthetics.
It is important to design the retaining wall with a "TOE" as above so the first course of blocks would be laid perpendicular so as to have a 18" footprint.
Answered 28th May 2012