Pre-Cast Foundation Pads for small structures
Pre-Cast Foundation Pads for small structures
(OP)
Hi,
I am trying to find technical design information on the use of pre-cast, ie above ground, concrete pads to support small lightly loaded structures. Something similar to temporary road barriers.
Of my concerns with employing such a structural foundation is:
1) soil settlement
2) soil movement due to shrinkage and swelling
I was also interested in whether anyone was aware of soil nails/anchors used in such an application to improve load capacity and reduce the impacts of the factors mentioned above.
Cheers Rich
I am trying to find technical design information on the use of pre-cast, ie above ground, concrete pads to support small lightly loaded structures. Something similar to temporary road barriers.
Of my concerns with employing such a structural foundation is:
1) soil settlement
2) soil movement due to shrinkage and swelling
I was also interested in whether anyone was aware of soil nails/anchors used in such an application to improve load capacity and reduce the impacts of the factors mentioned above.
Cheers Rich





RE: Pre-Cast Foundation Pads for small structures
RE: Pre-Cast Foundation Pads for small structures
Just out of curiosity, what type of road barrier uses concrete pads?
Hope this helps.
RE: Pre-Cast Foundation Pads for small structures
By lightly loaded I meant something similar to a pole mounted street sign, only with a larger swept area and therefore higher wind loads.
Preliminary design for such an above ground pad estimates a requirement of a square pre-cast pad ~700x700mm and ~150mm thick. Giving ~175kg of weight to support the attached structure.
Current geotech for the area of concern indicates potential seasonal movement of up to ~40mm, which for the application is of concern, as this is not a temporary installation, and this amount of movement may affect other aspects of the design.
In my limited knowledge of soil mechanics I understand that the first ~200mm of soil should be regarded as providing no bearing support for applied forces.
I am concerned that in addition to ground movement the structure will 'sink' over time. And so was interested in how to determine this?
And with respect to resisting environmental loads (ie wind) I was interested in possibly incorporating moulded-in stakes (i am currently calling them soil nails) to the pre-cast pad. These would be driven into the ground on installation beyond the ~200m top soil depth, primarily to reduce the amount of concrete required and size of the pad to improve on shipping costs etc.
At this stage looking for any similar applications and to expand my knowledge in this area...
Thanks again...Rich
RE: Pre-Cast Foundation Pads for small structures
RE: Pre-Cast Foundation Pads for small structures
In addition to the small pre-cast pad idea I was also pursuing screw piles / auger anchors? Possibly to be used in conjuction with a precast pad to increase load capacity. But again have no references to designing and utilising these products. Do these have to conform to any standards etc?
Rich
RE: Pre-Cast Foundation Pads for small structures
http://www.abchance.com/
As to the top 200mm, my guess is that is the typical thickness of topsoil in your area, this should be removed from below structural slabs and footings anyway.
Good luck.
RE: Pre-Cast Foundation Pads for small structures
http://www.pinfoundations.com/
It may be sutible to your application.
Steve
RE: Pre-Cast Foundation Pads for small structures
Abchance had some really good info and that pre-cast pin foundation is very interesting.
I passed some interlocked road barriers in the street the other day. Another potential solution that I am considering...
http://www.t-lok.com/
Rich