Cast-in-place concrete caisson for a wastewater lift station wet well, sunk and excavated from inside the shaft.
The caisson was formed and poured at grade with the cage left standing for the next lift, then advanced by digging inside the shaft with a long-reach machine and letting the structure sink under its own weight. Spoil came out over the wall, mats carried the excavator on the working platform, and every lift was shot for plumb before the next pour.
What we did
- Caisson forming and pour
- Reinforcing cage
- Excavation inside the shaft
- Plumb survey per lift
- Spoil handling and haul-off
- Working platform and matting
How we kept it safe
Nobody in the shaft while it is being dug — every bucket is handled from the surface. Spotters on the swing radius, matting under the machine, and edge protection on the collar between lifts.
Client
Municipal utility
County
Trinity, TX
Structure
Cast-in-place caisson
Method
Sunk from inside
Status
Active
Scope
Lift station wet well