The leaning Tower of Isaan

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Re: The leaning Tower of Isaan

Postby geordie » Tue Sep 18, 2012 3:38 pm

Just an opinion as ever :)
Before catastrophic failure the rebar will have to snap in the beams and masonary will start falling or crumbling before that giving further warning
At this stage serious monitoring is needed to see if it is on the move as well as some test holes next to footings an see whats gone wrong
If the pillar at the back is leaning inwards there must be a lean corresponding elwhere towards the front
The picture with the pipe is i suspect mostly the render although the smaller crack may indicate a deeper problem
The slab at the back lifting ? could it be its dropped, but because the colum has a lean its getting the blame for lifting when in reality its stationary
Underpinning may cure the problem but its dependant on the ground conditions it might pay to sacrifice the ground floor completely and pour a raft foundation ""under"" the ground beams
And a couple of large rebars drilled through the colums tied into the new concret as well
It maybe purely a case of inadequate footings poured in the first place i have seen an example of that two doors away a two floor extension and they dug down less than a meter round holes 600mm across ? can,t wait to see how long that lasts
If you were to find something similar the cure is simple dig down one footing at a time drill into the existin footing for rebar and enlarge it
Non of the above suggestions will help the "cosmetics that will be a seperate issue
my comments may be wrong but never deliberately
If it aint broke, dont fix it
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Re: The leaning Tower of Isaan

Postby Roger Ramjet » Tue Sep 18, 2012 4:29 pm

I agree with Geordie, but I would add this; verandas breakaway from houses because the veranda's footings are not sufficient or the house footings are not sufficient and the weight of the concrete and rebar in the veranda is greater than the support of the footings.
The cracking doesn't look good. If you can, drill into the crack and look at what's inside and to the sides. You should find rebar of a certain size. It would be nice to see that rebar and if there are hairline cracks running in either direction in the concrete. Don't leave the rebar exposed, render over the top or otherwise the exposed rebar will start to rust and add more problems.
As the slab has already broken away downstairs, it would pay to see how thick it is and again what's in it. I suspect they just free floated it without tie ins and forgot to add rebar and trench mesh, otherwise it would be in the air as the house slopes away from it.
It's time to start digging near the footings if you are going to save the structure, but I think it might just be a little too late.
If they should see cracks appearing where the beams join the columns, or hear "groans" or grating it's time to leave the house.
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Re: The leaning Tower of Isaan

Postby geordie » Tue Sep 18, 2012 6:08 pm

Looking again at the picture the verrand crack seems to me to be caused by the veranda being stable and the house wall dropping the crack runs the wrong way for it to be the verandah mobile
If i was the verandah i would expect the break directly on top of the colum and forward of it
Any remedial work should be done a meter at a time rather than all at once if piles are not required ?? if they are getting a rig small enough to drill inside will be an issue
my comments may be wrong but never deliberately
If it aint broke, dont fix it
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Re: The leaning Tower of Isaan

Postby ratsima » Thu Sep 20, 2012 7:52 pm

Thanks again for all the input, especially Geordie and Roger.

In the short term, I'm going to encourage the following things be done.
1. NOW - Some reference points built to track any movement over the coming months/years.
2. NOW - Dig up the ground slabs at corners B and C, including rerouting the drain at corner C. See what can be seen of the underground piles, footings. Assess the build quality of the slabs (as a rough and ready indicator of the general build quality, perhaps?).
3. When money and time allows, dig down externally below the columns B and C for detailed assessment of the build standard and prognosis for the columns. Extrapolate for the rest of the columns, footings.
4. If felt to be necessary, dig down at other columns for further assessment
5. Make a plan for fixing the footings and columns; if that can't be done, make a plan for eventual demolition.

Please advise of there are any important steps I have missed. The plan needs to be brief-ish, as low cost as possible until the big decisions have to be made otherwise the owners will go into denial and/or panic.
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