n3xt:


Baba, I proposed a different solution for your terrain which is on the receiving end of a very steep slope.

If you'll remember the pictures attached below. I made the drawing in 2013 to explain the solution. A v-ditch collects the water and takes it away from your property further down into communal drain.
The aim is to stop the inflow of water coming from uphill.

It's not a cheap solution because you'll have to take care of your property and all beside you to get result. The solution can mean acquiring the next plot to you to protect your property since no one is building after you and you're at the receiving end.

n3xt:
The building in question was 1m higher than the natural ground level at completion of the DPC that we had to use planks to climb into the building. I can remember the first day the wife of the client visited she cannot enter into the building and the client had to back her on the platform provided.

What ate up the foundation? Uncontrolled water dammed up on the land.

abdulwastecx:


The height of the foundation is adequate. The major problem is settlement which result from water entering the foundation. The solution now is how to divert water away from at least 3m away from the foundation perimeter

mavverick:
Oga

Take it easy on me, I was only reading out what i found in a textbook.
Lets assume the terrain is Lekki, loose soil, swampy land
Also, the piles dont have to be that deep though, I would have thought. You are right to also say that they would need to be brazed or chained together to maintain strength.

I would still be interested in seeing the figures if you can cost it out roughly please.

Thanks.

Oga I no fit na lol... I will get back to you on Whatsapp sir

mavverick:
Oga

Take it easy on me, I was only reading out what i found in a textbook.
Lets assume the terrain is Lekki, loose soil, swampy land
Also, the piles dont have to be that deep though, I would have thought. You are right to also say that they would need to be brazed or chained together to maintain strength.

I would still be interested in seeing the figures if you can cost it out roughly please.

Thanks.

Qc1:
I know there are a lot of professionals in regard to building and property here in this forum. I have some questions for you guys...

(1) This wasn't a good land to start with, it's a swampy and sloppy down the hill, maybe 20 feet to the main road. But the slop is gradually and steady. Within a month the house sank about 3 feet. I'm thinking this was because I rushed to roofing level in less than 7 weeks. I waited for about 10 months to proceed to next level because I was scared speed the building sank into land. Although the house sank another half a feet or so again but since then it has stopped. Thank God I had 14 coaches of blocks above the raft(which has since completely disappeared) on the main floor. There was a time the DPC was below the outside perimeters and I had to re-floor it again to be at the same level with the land.

Thank you all, I'm desperately in need of advises and ideas.

Qc1:

The house seems to have stop sinking just before the roofing reinforcement.

n3xt:
@ QC1 baba, sometimes last year you wrote this


https://www.nairaland.com/2486191/ikorodu-mansion-diy-report/2#36484247

Baba, the bolded part is one of the major mistakes you're doing while trying to fix this problem. The more load you impose while trying to raise your DPC, the faster the building continue to sink. There are times the person you really don't want to hear might be the person who has the right solution to your problem.
You agree the foundation sank, right? Would it have been different if the foundation is 10 boards? NO! It'll only take much longer time but the problem will still remain and the worse part is that the building can even tilt.



I thank God you heeded my advice to do underpinning the last time I visited the site (after January 2014) when I saw how fast the building is settling. I told you, no roof until the settlement is stopped and thank God you allowed me to implement the fix and it yielded a positive result. It stopped the settlement.

I went ahead to suggest other things that needed to be done but nothing was said about it. I wonder why you agreed with me that time to implement the underpinning fix as recommended and carried out by my men to stop the sinking.

I saw a bigger challenge then and proposed a fix but you saw a man who is after 50k egunje from a carpenter when I could have just move in to the site to roof the house just like every other tradespeople who have been patronizing the structure yet unable to recommend a good fix. Even though it was just only one visit in 2 years. I was able to spot and correct a major problem.
Since then, I just heard again from you.
Whether you choose to adopt them or not, I won't stop throwing the advices from here. It's all about finding solutions.

________
Bros, again the damn fence on the left must carry a very big drain or require you digging a big trench to collect all waters before channeling them down to the govt drainage because that side has always been the receiving end and that's where the larger water comes from. Interestingly, this fix doesn't have to be overly expensive. You can use earthbag to construct the trench and fill with construction wastes and Rubbles or sharp sands.

And a V-ditch on the right side to about 1.2m depth is very necessary. This will take care of any leaky pipes and re-routed pipes directinbf water into your foundation. You're not living there yet so you can't tell what might have happened overnight especially now that your building has been fenced out.

In a waterlogged terrain or flood zones, the fix is never ending. You need to constantly monitor the water level; clear the drainages; observe; check and check everything.

Qc1:



It's like you don't get it!


I DO NOT NEED ANY DAMN ADVICE, I NEED A FIX !!!


DON'T STAY HERE AND GIMME A LOAD OF CRAP, GO THERE TO FIX IT!

skimanski:
Hmmm!!! These pictures are just too scary. These land looks like an erosion settlement. I'm not sure the soil is good enough to hold your house, regardless of the water that flows in from drains. You better go an do a soil test before trouble shooting blindly. Because if the land is as bad as it looks to me, in simple English, your house will keep on trying to find a steady soil surface underneath the ground to stand on, that will cause it sinking further until it finds it.

Once you do a soil test, and find where the steady soil is, then a professional can give u a proper solution. I highly doubt that your major problem is that water coming into your land. Just go and do a soil test first.

n3xt:
@ Skimanski, I completely understand your point about soil test. And also I'm actually responding to this in case there are people who might be experiencing a similar situation so as to know exactly what causes and how best you can fix the problem.


Before anything, let's do a simple diagnosis or try to recreate the problem. You can't fix what you don't understand.

Let's put a ball in bowl filled with sand up to 1/2 of the bowl and water up to 1/4 of the bowl. The ball will stay despite having water underneath the sand.
Now, let's start to apply pressure (put more loads in case of structure) on the ball. The sand will witness upward lift on all sides.

Again, let's start to put more water without a drain off point up to 3/4 of the bowl, what happens the ball will be lifted. Now, if the ball is under a pressure that suppresses the upward lift, water will find a way into the structure through cracks and holes on the slab.

Now, let's do the same experiments using granite as the base, if water level continues to increase in the bowl, there may be uplift or total disconnection of the footing from the bearing soil.

I hope this simple analogy will make any meaning to us now to be able to diagnose the problem and the fixes.

But just like you rightly recommended, I think an independent water/foundation expert should take a look and recommend a fix.
I believe it can be fixed. It just shouldn't be too long and work must stop at least for the time being.

_______
As it is, the ponding water is causing upward lift of the slab. That's the reason why water is found in the building and not outside because the slab is resisting the water.
Such a challenge can only be fixed by reducing the water level or keeping an eye on the flood level.

n3xt:
@ Qc1

Can we take this to private chat? Who will be at the site?
Also have you been able to complete your septic tank? Cos I may need it for a different purpose.

n3xt:
I'll visit but I'm tempted to ask this question bros.

What part of the house is that? Is it the private lounge? Or the guest bedroom? Or the main lounge?

The private lounge at the void section and guest bedroom are highly susceptible based on what I saw during my last visit. Especially the guest bedroom.

From the last pictures, I know you won't have such issue in the kitchen, dining and the bedrooms at the back.

Qc1:



I'm thinking settling in the guest room/ante room since it's the most affected in the house. I'm not trying to put any weight, just the painting and tiles.

n3xt:


I guess as much cos those areas were stepped down by one board. And I am not leaving out the possibility of seepage or water ingress from the wall.

Qc1:



Those pics were of resent, If you want to go there and do your ditch, the time is now. Moreover, it wont hurt you to go there yourself!

n3xt:


I'll be there. I just need to get more info. I'm sure you know nobody can do better explanation than yourself cos we're both in it from the beginning. And you'll understand everything I'm saying faster than anyone else.

If the picture you posted yesterday is from any of those two areas mentioned (private lounge or guest bedroom, or underneath the stairwell, let me congratulate you and ask you to put your mind at rest.

Those areas have already gone beyond flood level when I last visited and that's What made me to quickly suggest underpinning.

So if you're seeing water in those areas, I can understand.

Qc1:



YES to the bolded.

n3xt:


Ok. If that's the case, the fix been applied is not the final solution. The walls equally need to be replaced with impermeable solutions 600mm down the DPC and 600mm above the DPC.

I saw blocks and slurry concrete in one of the fixes done. That won't work. Anything that will not allow water to flow is what we need.

Meanwhile, let me check and see what I can come up with after my visit.

Thanks for your understanding bro.

mavverick:
Is this the way forward, and I wonder how much it will cost for a 60 x 120 standard plot. Using this short bored pile vs 2 board raft all the way around.



EFFICIENT TO USE SHORT BORED PILES FOR PERIMETER FENCING IN SWAMPY AREAS?


It makes more economic sense to use short bored piles for perimeter fencing in swampy areas than to use raft or deep strip foundation which is in common use, it has been observed. However it is important to do it the right way. Generally, perimeter fence consists of non-load bearing walls or partially load-bearing walls depending on its use and configuration; hence the use of short bored piles is structurally permissible. By constructing reinforced concrete piles with adequate spacing, usually not more than 6m apart and capping them together longitudinally, fence walls of up to 4m can be built directly over the cap (or longitudinal bearing) saving the volume of concrete by up to 50%. Apart from being economical to use short bored piles capped together, it is equally structurally efficient.

Short bored piles are so called because they are constructed by boring the ground and then filling with reinforced concrete or mass concrete and they normally do not exceed 5-metres in depth. They are relatively easier and quicker to construct unlike the longer ones. Once the depth of suitable soil strata is established, rather than constructing raft or strip which consumes cost associated with trench excavation, formwork consisting of several boards lapped together with a lot of bracing as well as heavy reinforcement accompanying the concrete in foundation which is the common practice, it is faster and cheaper to use short bored piles.

Once the fencing layer is filled, prepared and the boring points are marked, the boring is done simultaneously with the insertion of the reinforcing steel piles (usually no casing is required) and concrete in an operation that may not usually do not last more than 30 minutes per point depending on the nature of the soil beneath. When the piles are set, a network of steel reinforcement is used to cap the starter bars of all the piles together. Te set up is casted in concrete and is now set to receive the blocks or bricks for the fence. Presently, it cost an average of 10,000 NGN (depending on the area) to bore and fill a point. Hence for a 36m length which could be one face of a standard plot, only about 7 points is required and the volume of concrete is therefore minimal. With the cost per cubic metre of concrete still hovering around 30,000 NGN, it is more than logical to conclude that short bored pile foundation for perimeter fencing in swampy or water-logged areas is the way to go especially for large areas like residential estates, industrial complexes, etc.

Culled from Castles Magazine.
Article by Engr. Osaz ENOBAKHARE

agarawu23:
Quack engineers everywhere. https://www.nairaland.com/3102738/shopping-complex-collapses-itoku-abeokuta

I will rada put "baba mufu" with 30 years of experience in my site than some engineers that will be blowing grammar I don't understand.

Hahahaha, l can supervise your site if you are ready to pay me good money, mind you, before we start, you will sign an agreement with me, deposit 90% of the fund in my account, you must not question my professional competence all through the project, l will deliver your building within 90 days, if you agree, drop your number here and lets take it from there, Lol, just kidding with you , you have a point though

Lol @ the bold, l wont blow big grammar, l will get hausa, igbo, french, Japanese, Arabic, yoruba interpreters to explain to you in whatever language of your choice

jeftalene:



Thanks Mavverick for putting my article forward to enlighten people.