Manitoba, Canada: Cement-Bentonite Slurry Wall Installation, Dam Upgrade
This project included the construction of a full scale cement-bentonite slurry wall after Geo-Solutions performed a pilot constructability test section in 2012. Geo-Solutions installed the cement-bentonite slurry wall through the slag overburden material used to construct a dam. The project involved a railway dam constructed to support a planned raise in the water level of a tailings basin. The dam was constructed using two waste rock filled berms spaced approximately 120 feet apart and the area between was filled with slag. For this project, a cement-bentonite slurry wall was installed through the slag overburden and anchored into the native clay or into bedrock. The purpose of the wall was to create an impermeable barrier through the slag filled portion of the dam.
For the construction effort, GSI provided technical assistance services for the installation of the cement-bentonite cutoff wall. The technical assistance services included a mixing plant operator, slurry specialist, Quality Control technician, and specialty equipment. GSI's specialty equipment included; a custom long stick attachment to fit a Komatsu PC 400 excavator, a cement-bentonite continuous mixing plant, bentonite slurry mix plant and associated pumps.
The cement-bentonite slurry wall exceeded the expectations of the 28-day strength (unconfined compressive strength) of 30 PSI and met the permeability requirements in the 10-6 cm/sec range. The project was completed with zero incidents, on time and within budget.