Soil erosion?

[RAZZELL]

There are a few cheap houses near me in Lat Krabang - bank repossessions.

 

They all seem to be suffering from soil erosion (see pics)

 

I "think" it is where the land has not been compacted properly. The main house stuctures are not affected ie no cracks.

 

Can anyone shed light on what exactly has happened?

 

RAZZ

Edited February 7, 2018 by RAZZELL

[johng]

That looks pretty bad. There might be a sink hole under there or a big stormwater/sewage pipe broke and soi is leaching away.
Maybe even water main burst.

Are these houses rasied up in relation to the road or nearby houses ? If possible walk round the perimeter of the estate and see if you can spot flowing water.

Might be "difficult" to get any one to take responsibility for a fix of the problem.

[Halfaboy]

I would call it subsidence. The sand brought in as landfill did not get enough time to compact resulting in what you see on the picture. The houses themself will not subside too much as these are built on piles.

 

Note easy to sell I think....

[RAZZELL]

So you just have to "relevel"  or raise the surrounding garden/soil?

 

There are about 20 houses or more on the estate like this.

 

All structurally sound apart from this.

 

RAZZ

 

 

[johng]

7 minutes ago, RAZZELL said:

So you just have to "relevel"  or raise the surrounding garden/soil?

Maybe  .. but maybe the new soil will just go the same way as the old soil  so you need to find the cause first...or wait for someone else to "relevel" and watch what happens  If a year or so later ( one rainy season) the soil is still there then you'll maybe /probably be ok-issshh !

 

Another thing to worry about these "raised up" land plots is what was used to bulk out the soil,  on a lot of plots I've seen household rubbish

and building rubble + god knows what else.

Edited February 9, 2018 by johng

[Halfaboy]

Maybe I am wrong, but isn't Latkrabang close to the airport ? This area used to be a swamp area. That means that also the layer below the refill layer (the underground) might be unstable / weak / swampy.

 

You will need an experienced engineer coming up with a solution (if any).

[Morch]

On 2/7/2018 at 1:41 PM, Halfaboy said:

I would call it subsidence. The sand brought in as landfill did not get enough time to compact resulting in what you see on the picture. The houses themself will not subside too much as these are built on piles.

 

Note easy to sell I think....

 

Seen a lot of that on quite a few projects. One house we were really interested in was dropped off the list on these grounds, although BiL (construction engineer) opined that it's probably not a big deal, provided piles and footings are checked and ok'ed. House was bought by someone else, who promptly did a paint job, sealed the gap and flipped the house for a bit extra. 

[RAZZELL]

On 09/02/2018 at 5:56 AM, Morch said:

 

Seen a lot of that on quite a few projects. One house we were really interested in was dropped off the list on these grounds, although BiL (construction engineer) opined that it's probably not a big deal, provided piles and footings are checked and ok'ed. House was bought by someone else, who promptly did a paint job, sealed the gap and flipped the house for a bit extra. 

 

Exactly.

 

There must be about 20+ houses or more like this.

 

None have horizontal/vertical structural cracks. I'm not really sure if it's that big a deal?

 

RAZZ

[MaeJoMTB]

they put foundations under the house, but not under the patio/driveway.

Nothing to worry about, the house looks fine.

Mine is the same.

 

As others have said, the garden fill soil erodes/sinks, but the house is sitting on the lower compacted soil levels is unaffected.

Edited February 12, 2018 by MaeJoMTB

[Pib]

As already mentioned the house itself probably has a solid foundation....expect the foundation is laid on numerous concrete & rebar poles approx 20 meters in the length driven into the ground until they hit solid ground/bedrock....then the foundation was laid on those poles.   The Bangkok area generally requires poles that long for good house foundations.  

 

However, the carport area obviously was not laid on long poles....they may have not have used any poles driven in the ground or used much shorter poles of only 2 to 3 meters in length.  And no poles in the ground were used around the house as no foundation was needed there.

 

I will have to say that's the most land subsistence I've seen around a house in the Bangkok area.  I have a 10 year house (bought new by the wife and I)in the western Bangkok area (house foundation laid on long poles in the ground).  I was told by the builder the poles used for the houses in the moobaan were approx 21 meters in length....that's how deep they had to be driven. 

 

Over those 10 year the house has developed no wall cracks or subsided....but the carport and a patio on the back of the house has subsided around one-half (1/2) of an inch which some re-grouting fixed (did that just a few months ago) to where it looks new since it didn't subside below the sounding concrete of the house structure.    Don't know how long the poles were for the carport....and the patio was laid after the house was built using 2 meter in length poles in the ground. 

 

Yeap, I expect the house in the pictures above is solid with a foundation of  "l......o........n.......g" concrete poles supporting it.   The carport foundation would need to be redone....broken up and the a solid foundation built under it before resurfacing.  The ground surrounding house is just going to need some truck loads of dirt brought in.