Diversion of Existing River

[bnard]

An existing river 3m wide with recorded water elevation at 1.25m during dry season and 2.5 during rainy season was diverted to give way for the subdivision development. Backfilling was made but compaction requirements were not observed w/c is at every 6". Residential houses built on top of the former river line shows signs of slab and wall cracking.
Surveys were conducted and found out that settlement indeed occurs. Remedial measures were made like injecting grouts within the perimeter wall foundation. There are 10 houses constructed on top of the former river line and only 3 shows signs of significant cracks.
Will there be any other applicable measures aside from grouts? Your assistance is very much appreciated.

 

[Maury]

It's unlikely tht the houses will settle uniformly, and the differential settlement of each house is going to cause structural problems that won't be remedied by patching. I'm afraid that the worst is yet to come.

 

[bnard]

Thanks Maury, based from soil test that was conducted, water is still flowing underneath at a depth of 5m. Is there any way to shut off the floe from the upstream end where the river was diverted?

 

[Maury]

A slurry wall might do the job, but you'll need a significant number of soil borings to identify the extent of the permeable soil and determine where the water will go once it is dammed. You don't want to just shift the problem to other houses. I suggest that you employ a very good soils engineer.