Slurry walls can provide groundwater cutoffs or structural support of excavations.
- Control groundwater
- Reinforce excavations and structures
The construction of slurry walls begins with excavating the trench with the use of either bentonite slurry or cement-bentonite to avoid collapse. For cement-bentonite walls specifically, it hardens in the trench to create the wall. For soil-bentonite slurry walls, the bentonite is mixed with the excavated soil and then put back into the trench. The completed wall creates a low permeability groundwater barrier.
When constructing a structural diaphragm slurry wall, individual panels are excavated using a clam-shell bucket to create the design depth wall. Bentonite slurry is added during excavation to prevent caving. Once design depth is reached, concrete is pumped to the bottom through a tremie pipe to displace the slurry and then steel reinforcement is added.
Slurry cut-off walls can also be constructed using a non-traditional, vibrating beam method. Steel beams are driven to design depth along the slurry wall alignment using a vibratory hammer. During insertion and removal of the beam, cement-bentonite slurry is added. A continuous barrier is created by overlapping each penetration. The finished product is a low permeability, groundwater barrier.