|
Posted by Troppo on November 17, 2007, 6:31 am
>
>> Here is S.Africa, where they had a burglary over a 1 meter high wall,
>> they have highened the wall to 3 m. with old-used [but good quality]
>> bricks which they had lying around.
>>
>> I have heard of free-standing walls collapsing and killing persons,
>> eg. in a storm.
>
> It happens.
>
>> Apparently free-standing walls should have 'posts' built from eg.
>> 4-bricks at specified intervals ?
>
> "Pilasters."
>
>> Since the government building inspection department is probably
>> non-functional since the recent 'liberation take over', I'd like
>> some international advice.
>>
>> The bricks are British imperial sized: 75x 110x 230 mm.
>> The wall is double bricked, with 'cross-layed' at the top.
>>
>> [...]
>
> Another variable to consider is the straight length of the masonry
> wall. Walls with jogs, spaced closely enough, buttress themselves.
> (Our code here calls for intersecting walls or buttresses (pilasters)
> at no more than 36x the wall thickness for non-loadbearing walls.)
The UK codes have something similar - can't remember the ratio, 25 years
since I last had to use it - but that code didn't have seismic
requirements, or much in the way of wind-loading for free-standing, as I
recall.
Avoidance of pilasters would require some form of reinforced bond beam
coping, maybe post-tensioned rods, foundation to coping at ?? spacing.
Easier to do it in hollow masonry block. Keep the bricks for decorative
paving. Or crush into pea-gravel for the same purpose :-)
> At 3m high and presumably 230 thickness you are at 13x thickness which
> is a bit higher than my engineer would permit...If you are concerned,
> you should have a pro look at it, or stay away from it, especially in
> a good wind or if people are operating vehicles near it.
Once saw an example of something like this - free-standing wall at the
side of a fire station. The wall was post-tensioned, eg threaded rods
from top to foundation. A fire truck is capable of packing a punch ...
|