Stone Columns with Vibroflot
258 Wet Top Feed Stone Columns
Molson Peak Brewery in Chilliwack (BC) needed to have a wastewater treatment plant facility built. Liquefaction treatment was required under the structure.
The site’s subsurface stratigraphy consisted of the following:
• Approx. 0.5m of compact to organic ground;
• Underlain by 4m of soft to firm clay to silty clay;
• Underlain by 7m of loose to compact silty sand to sand susceptible to liquefaction;
Groundwater was encountered at approximately 2m from the ground surface.
Vibro Replacement stone column densification was required beneath the new wastewater treatment plant in order to prevent settlement caused by soil liquefaction in the event of an earthquake.
Menard utilized Wet-top-feed stone column installation techniques which was the preferred method of the General Contractor. Stone columns were installed to 11m depth on a regular grid pattern to meet the specified CPT tip resistance performance-based requirements.
Densification work began with an initial trial area consisting of 20 stone columns to assess the effectiveness of the proposed methods and stone column spacing. Production work applied similar methodologies to those proven successful in the trial area.