1,160m² of Vibro Replacement stone column densification to a treatment depth of 12m

Fraser Health Authority is constructing a two-storey building as the expansion of Delta Hospital, Delta.

The site’s subsurface stratigraphy consisted of the following:

• Approximate 1.5m of loose to compact Fill comprised of sand with variable amounts of silt and some gravel;
• Underlain by 1 to 2m of soft to firm sandy silt/clayey silt;
• Underlain by 4 to 5m of soft to firm sandy silt/silty sand.

Underlain by 9m of loose to compact sand and silty sand.

The subject building would be a post-disaster facility and should remain in service following or shortly after a major earthquake. As such, in order to reduce the anticipated post-seismic ground displacements caused by liquefaction of the native soft silt and loose sand, stone columns are required to mitigate the seismic hazard during major earthquake event.

Menard utilized dry bottom feed Vibro Replacement equipment and techniques to install stone columns to a depth of 12m below site grades.

Cone Penetration Testing confirmed the ground densification program achieved the specified performance criteria.