Need some DEEP French Drains, how can I do this or hire someone?

[Egon]

What you see is the engineer recommending putting piers under 3/4 of the house to match the side that is HIGHER. The low side is because of all the heaving on the LEFT side in the diagram (the E> marks).

The uneven nature of the slab is interesting. Has one side been elevated by swollen clay or has the other side subsided due to improper compaction of materials used to build the area up or the rotting of organic material?

Are the soils on different sides of the house different?

Neither of the previous Engineers did any core samples I gather?

If the soil is the same under the house and there is lots of water the expansion should be the same under the whole house?

I would suggest core samples will be required and I am suggesting that once the soil is dewatered the floor will still not be level.

Sort of negative questions and statements but I fear the solution may be costly.

There should be a Structural engineer and a Geotechnical engineer involved.

Note: I've no credentials to my name

 

[mancho]

I have tried to answer you questions:

Has one side been elevated by swollen clay or has the other side subsided due to improper compaction of materials used to build the area up or the rotting of organic material?

This could be the case, but nothing on the top soil shows any difference. It's the verbal opinions of the engineers that the heaving side is pushing down the low side. It's possible that it's lack of ground compact on the low side, but note, the two that did reports said if the clay soil is dried out, the house would eventually sit back down, maybe not perfect, but it would drop significantly.

Are the soils on different sides of the house different?

Not really... topsoil then clay.

Neither of the previous Engineers did any core samples I gather?

Nope, no soil samples.

If the soil is the same under the house and there is lots of water the expansion should be the same under the whole house?

well, perhaps, but if the water is doing a "straight" line downhill, it's possible that it won't get near the SOUTH side of the house... it would clip the EAST and NORTH side...

I would suggest core samples will be required and I am suggesting that once the soil is dewatered the floor will still not be level.

I don't know, but you might be right.

There should be a Structural engineer and a Geotechnical engineer involved.

I've hired two structural engineers, and I need a hydrologist or Geotechnical engineer next...

 

[California]

Just a simple comment based on your marked-up aerial photo: If the water is flowing into the property from the alley side, why not install a curb with a deep foundation along your boundary with the alley to shunt the water right down the alley? It would probably be a good idea to get together with neighbors and extend this curb behind everyone's house on the block at the same time.

 

[mancho]

Just a simple comment based on your marked-up aerial photo: If the water is flowing into the property from the alley side, why not install a curb with a deep foundation along your boundary with the alley to shunt the water right down the alley? It would probably be a good idea to get together with neighbors and extend this curb behind everyone's house on the block at the same time.

While I do like that idea... the alley behind has major power lines buried right there.

 

[2manyrocks]

He say's it's most likely not the utility but a tributary... but isn't all streams a tributary at some point? OK, I would like that idea, but that makes it:

.

Is there a local college with a geology dept nearby? Looked at any topo maps of the area before it was developed?

Is your house resting on one kind of clay on one side and another kind on the other that are moving at different rates?

 

[CurlyDave]

While I do like that idea... the alley behind has major power lines buried right there.

A buried power line is supposed to be able to take any amount of water in the soil.

 

[California]

I think he means he is prohibited from trenching there. (To build a curb with a substantial foundation as I suggested).

 

[Taylortractornut]

I would deal with the surface water first to rule out surface to ground infiltration. Im not knowlegable in Texas clay as our clay is different. As a dirt mover Im betting someone has filled and not compacted, or filled in a spring area. Or in the the case of my own back yard they bulldozed the trees and brush and put clay fill over them and its making a french drain bringing the water to you.

I would put a swale or berm on the high side of the property and direct the water around to the main runoff drain. I recently did a job for some folks that had a frame house that had the peirs sinking. He hadsurface water entering the ground at the top of his property and seeping under his house. we put in a berm and stopped it for now we will check a bit late

r and see if it needs drains. . My backyard when I was a kid was sinking. The back porch is still settling now. What happened back in the 70's when Mom and dad first moved back here and they bought this house it had been moved from the town that the Tenn Tom waterway was about to get. The site had been fixed by a a dozer owner to put it best. They leveled the site and all the big white oak trees and such went into the gully noth the yard. The old gully was the old stage coach road that ran though here since the 1850s. It had erroded about 10 feet deep when the trees had been put in it. The folks that had it done owned the house about 10 years till My parents had it and we didnt know what was down there.

Dad noticed the new concrete porch settling and then the yard had gotten a few sink holes here and there. dad left it to reason that there may have been a stump or 2 left there. Then one day mom was walking across the yard with me al lof a sudden she and I were eye to eye. She had fallen waste deep in the ground. Dad came home from work as their project was done and had the company backhoe waiting on the next travel order. He dug a tes hole and hit the first layer of oak trees. Some were 36 inches in diameter. He dug as deep and as wide as the 580 Case would reach and got all the trees out. I remember the stench of the old wet clay and dad cutting al lthe trees up splitting them for firewood. He arranged for the cleanup debris like loose rip rap from the the stock piles and clay from the Tenn Tom's clean up could be dumped here.

Dad the ncarefully backfilled and compacted it all back. The water came in the ground from the surface ditches.

 

[2manyrocks]

That's the voice of experience speaking right there.

I was just stumbling around thinking if you could find a former topographical map of the site, then you could figure out where they filled in.

Another idea is to go to a place like this and hope they made and still have pictures of the site as it previously existed. TerraServer - The Leader In Online Imagery - Aerial Photos & Satellite Images

 

[California]

Or the land surveyor who laid out the lots.