Column footings

Almost everything that needs to be said about concrete, cement, hand-mixing, uses and prices has been said on this forum. Please check out the contributions before posting new questions.

Moderators: Sometimewoodworker, MGV12, BKKBILL, pattayapope

Re: Column footings

Postby Roger Ramjet » Sun Dec 18, 2011 4:51 pm

Trader,
Just for your information my house is built off the ground over one metre and I have 51 bore piles. If you would care to look at Dozer's build he was building at ground level, which is where his beams sat....on the ground, which is where the weight would have been carried. The columns would have carried the weight of the roof, the weight of the beams would or should have been carried by the ground.... if he used them.
User avatar
Roger Ramjet
 
Posts: 5251
Joined: Tue Apr 27, 2010 12:55 pm

Re: Column footings

Postby trader » Sun Dec 18, 2011 5:03 pm

Roger Ramjet wrote:Trader,
Just for your info.


r/r :D mgv12 addressed the question to you not me :)

have a nice day :D
trader
 
Posts: 94
Joined: Sun Oct 30, 2011 3:44 pm

Re: Column footings

Postby Roger Ramjet » Sun Dec 18, 2011 7:00 pm

trader,
I am well aware MGV12 addressed the question to me and like his pond I chose to ignore it for the same reasons I just stated.
User avatar
Roger Ramjet
 
Posts: 5251
Joined: Tue Apr 27, 2010 12:55 pm

Re: Column footings

Postby MGV12 » Sun Dec 18, 2011 10:37 pm

Roger Ramjet wrote:trader,
I am well aware MGV12 addressed the question to me and like his pond I chose to ignore it for the same reasons I just stated.


Have a chat with your engineer RR as he should be able to clarify the situation; I don't see this diversion being of any value to the OP.

“Some days I am an optimistic pessimist ... other days I am a pessimistic optimist”
User avatar
MGV12
 
Posts: 5349
Joined: Wed Jan 23, 2008 4:23 pm
Location: Chiang Mai

Re: Column footings

Postby Roger Ramjet » Mon Dec 19, 2011 6:43 am

MGV12,
To be honest I haven't seen anything that even relates to Dozer's build and the question about his footings in the last 10 posts.
User avatar
Roger Ramjet
 
Posts: 5251
Joined: Tue Apr 27, 2010 12:55 pm

Re: Column footings

Postby MGV12 » Mon Dec 19, 2011 6:52 am

Can we get back on track now gentlemen ... if there is anything more to add ... 'Column Footings'

“Some days I am an optimistic pessimist ... other days I am a pessimistic optimist”
User avatar
MGV12
 
Posts: 5349
Joined: Wed Jan 23, 2008 4:23 pm
Location: Chiang Mai

Re: Column footings

Postby John » Mon Dec 19, 2011 7:29 pm

Roger Ramjet wrote:Trader,
Just for your information my house is built off the ground over one metre and I have 51 bore piles. If you would care to look at Dozer's build he was building at ground level, which is where his beams sat....on the ground, which is where the weight would have been carried. The columns would have carried the weight of the roof, the weight of the beams would or should have been carried by the ground.... if he used them.


Then please explain why if I remove all of the dirt form under Dozer's beams his walls will not collapse. I think MGV12's idea is good, have a chat with an engineer.

It's not good to leave topics hanging with information that might later give others the wrong idea.
John
 
Posts: 171
Joined: Sat Jul 30, 2005 4:33 pm
Location: UK And Thailand

Re: Column footings

Postby Roger Ramjet » Mon Dec 19, 2011 9:03 pm

John,
It's as I said earlier...does Dozer have beams? Do the beams rest on the ground? If they do, and please take into consideration the size of the columns, then would that column solely support the weight of both the beams and the roof, or would the ground also displace some of the weight?
User avatar
Roger Ramjet
 
Posts: 5251
Joined: Tue Apr 27, 2010 12:55 pm

Re: Column footings

Postby geordie » Tue Dec 20, 2011 8:33 am

John i think you know RR was being faceasious when he made the statement he is in fact right though you can use purely a beam to support a wall !! just not using the thai material generally available! As you know in the uk we do it daily and bury it a meter plus :lol:
The way the houses are engineered over there with a frame construction its all tied in anyway
but the one certanty is using their cement blocks and no colums would make for a very low roof ""about ground level""So the main aim of the colums is to keep the roof up where it works better its really a daft discusion anyway because without the footings nothing will stand up for any length of time Not the walls or the roof !
There are exceptions if you can convince the builder you could using the right blocks or bricks build without any need for the colums but i only know of one success on that score
my comments may be wrong but never deliberately
If it aint broke, dont fix it
User avatar
geordie
 
Posts: 3867
Joined: Sun Oct 12, 2008 4:39 am

Re: Column footings

Postby MGV12 » Tue Dec 20, 2011 1:19 pm

I can only imagine the confusion in the minds of those who have never built before; let alone in Thailand.

There are many different practices employed around the World for house building ... here it's predominantly the skeletal beam and column system; where every part of the structure is supported via posts/footings.

Yes a load-bearing wall structure, where everything is supported off a continuous trench footing, can be be built here successfully; I am currently living in such a dwelling.

The widespread practice is however columns and beams. To attempt to have 'floating' walls or beams within that structure is both unsafe and will inevitably lead to major cracks developing; or worse. Whether the 'ground' beam actually sits on the ground or not is irrelevant, it is engineered within the structure to support the walls via the columns and posts/footings. I have never encountered a situation where a competent engineer discounts the loadings of the walls and ground beam from his/her calculation; and suggest the Tessaban would not approve it for a building permit if he/she did. A ground beam is sometimes actually sat on the ground to reduce the amount of formwork, aesthetics or other considerations .. it's never intended to solely support any part of the structure by any contractor/engineer who knows what they are doing.

“Some days I am an optimistic pessimist ... other days I am a pessimistic optimist”
User avatar
MGV12
 
Posts: 5349
Joined: Wed Jan 23, 2008 4:23 pm
Location: Chiang Mai

Re: Column footings

Postby Roger Ramjet » Tue Dec 20, 2011 3:12 pm

MGV12,
Then how would you describe a free floating slab construction with neither footings, beams nor columns? And the walls supporting the roof.
User avatar
Roger Ramjet
 
Posts: 5251
Joined: Tue Apr 27, 2010 12:55 pm

Re: Column footings

Postby MGV12 » Tue Dec 20, 2011 3:48 pm

Roger Ramjet wrote:MGV12,
Then how would you describe a free floating slab construction with neither footings, beams nor columns? And the walls supporting the roof.


Not dissimilar in many regards to the continuous strip trench approach; and even less applicable to this thread which is about Column Footings

“Some days I am an optimistic pessimist ... other days I am a pessimistic optimist”
User avatar
MGV12
 
Posts: 5349
Joined: Wed Jan 23, 2008 4:23 pm
Location: Chiang Mai

Re: Column footings

Postby otis-a » Tue Dec 20, 2011 4:27 pm

were i setting the inputs to a structural analysis program:
i would ignore any support of ground beam sitting on unconcolidated earth.
Reason: predicting settlement of earth consolidated for 3to24 month is just too dodgey
rr is correct
ground beams will recieve some support from earth
however it would be imprudent to count that support:
engineer all support to column FootingS
my educated guess as non structural engineer who aced his structures class but ''c''d his steel design under promise to not engineer any more steel but using tested rot's as they do not conform exactly to aisc codes.
where to park dog when in town? A barking lot... :-)))
User avatar
otis-a
 
Posts: 1206
Joined: Sat Jun 19, 2010 8:26 am
Location: thai/usa

Re: Column footings

Postby MGV12 » Tue Dec 20, 2011 6:33 pm

otis-a wrote:were i setting the inputs to a structural analysis program:
i would ignore any support of ground beam sitting on unconcolidated earth.
Reason: predicting settlement of earth consolidated for 3to24 month is just too dodgey
rr is correct
ground beams will recieve some support from earth
however it would be imprudent to count that support:
engineer all support to column FootingS
my educated guess as non structural engineer who aced his structures class but ''c''d his steel design under promise to not engineer any more steel but using tested rot's as they do not conform exactly to aisc codes.


As you say Otis "it would be imprudent to count that support" ... when engineering a house construction you never rely on the unreliable; especially in a 'developing country'.

RR ... for a guy who is consciously and intentionally over-engineering your build I fail to see where you are coming from on this 'debate'.

“Some days I am an optimistic pessimist ... other days I am a pessimistic optimist”
User avatar
MGV12
 
Posts: 5349
Joined: Wed Jan 23, 2008 4:23 pm
Location: Chiang Mai

Re: Column footings

Postby geordie » Tue Dec 20, 2011 6:51 pm

otis-a wrote:were i setting the inputs to a structural analysis program:
i would ignore any support of ground beam sitting on """"" unconcolidated earth."""""""""""
Reason: predicting settlement of earth consolidated for 3to24 month is just too dodgey
rr is correct
ground beams will recieve some support from earth
however it would be imprudent to count that support:
engineer all support to column FootingS
my educated guess as non structural engineer who aced his structures class but ''c''d his steel design under promise to not engineer any more steel but using tested rot's as they do not conform exactly to aisc codes.


If you were dealing with consolidated earth reality says the weight will disapate to the footings anyway through the colums the aim being exactly that an even spread of the various loads onto reasonable compacted ground

The situation alters with the use of a raft foundation where the aim is to spread the load evenly over a larger area reducing the ground pressure at any given point
a stilleto heel or snow shoe situation
But equally important when considering a raft is the load on it has to have an even distribution you would not for instance make a 30 mtr 10 mtr raft then build a 10x10mtr two story house at the back of the slab ?? not without the risk of tilting it but another consideration when building a raft is the location of walls and disapation of the weight from them normally you can reduce the non load bearing beams and enhance the load bearers but generally you woul ensure than any and every beam would resist flexing with the weight
my comments may be wrong but never deliberately
If it aint broke, dont fix it
User avatar
geordie
 
Posts: 3867
Joined: Sun Oct 12, 2008 4:39 am

PreviousNext

Return to cement, concrete and mortar

Who is online

Users browsing this forum: No registered users and 1 guest