Holdfast Training Services Trial Blog

The sub-contractor wants to backfill the core (big hole in the picture) with spoil from on site to support the slab on ground that will be locked into the lift core. The core is currently open with 1.5 m benches down the base footing and the backfill will be approximately 3 m deep.

The material is crushed phyllite which has ended up like brown clayey GRAVEL. I needed a CBR of 15 the CBR rating indicates 20, what did I miss.  CBR link.

I was talking to the Geotechnical Engineer when I discovered that I am idiot (we already know that my subbie is an idiot).  Hint the core is likely to be wet.