Unsuitable Soil

[JKJohn]

One situation in two different projects:
1- Area under S.O.G.. Unsuitable soil was found and removed. The testing agency proposed filling with geotextile fabric with 57 stone. The Geotechincal Engineer rejected it.
2- Area under road. Unsuitable soil was found and removed. The testing agency proposed the same solution mentioned above. The Geotechnical Engineer accepted it.

I am confused. Could someone shed a light?

Thanks in advanced!!

 

[Ron]

It depends on what was below the soil where geotextile was placed and the use. In the case of a slab on grade or similar, the structure is static and long term, thus the concern is settlement and migration of smaller particles into the No. 57 stone.

For the pavement area, the loadings are not consistent, are transient and more concern is placed on the pore pressure effect of loading than the long term loading effects.

The Geotech is correct on both.

 

[oldestguy]

For number 1 I'd ask for an explanation, because you state all the unsuitable soil was removed. The reason for rejection might be something such as insufficient width of poor soil removal. Again it is difficult to do a good job of placing fabric. Could be what Ron says, who knows.