34 CFA piles 600 mm diameter x 20.0 m deep
1220 CMC – 340 mm diameter x 18.0 m deep
The Vancouver International Airport Authority is expanding the international terminal with additional
gates at Pier D.
The site’s subsurface stratigraphy consisted of the following:
Approx. 3m of compact to medium dense sand fill with some silt and gravel;
Underlain by 1m of soft to firm clay to silty clay;
Underlain by 14m of loose to compact silty sand to sand susceptible to liquefaction;
Over firm to stiff marine silt.
Groundwater was encountered at approximately 1.5m from the ground surface.
Vibro Replacement stone column densification was required beneath the new building in order to
prevent settlement caused by soil liquefaction in the event of an earthquake.
Menard utilized dry-bottom-feed stone column installation techniques which was the preferred
method of the General Contractor. Stone columns were installed to 15m 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.
Special precautions were implemented to avoid distress to an existing jet fuel line located within 2m
of densification limits. Menard first pre-bored and cased the upper 3m of the nearest stone
columns, and coordinated with the Engineer who monitored vibration, settlement and pressure of
the fuel line during stone column installation.