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PROJECTDESCRIPTION

DEEP SOIL MIXING GROUNDIMPROVEMENT

GAIA Contractors has successfully completed on schedule the stabilization of theground at the City of Nanaimos Vancouver Island Conference Center (VICC).GAIAs approach, using state-of-the-art deep soil mixing (DSM) equipment,resulted in final construction costs substantially lower than would have been thecase using one of the more traditional methods previously considered.

This part of old downtown Nanaimo is built on an area that was once a sandstoneinlet complete with harbour and docks. Now in-filled with material varying fromsandy soils to wood debris to blast rock, the site of the VICC was susceptible toliquefaction and large scale movement in the event of an earthquake, posing asignificant risk of settlement or even collapse of the proposed structure.

GAIA proposed and implemented a three-fold solution consisting of preliminaryground densification using rapid impact compaction, shallow soil mixing at selectfooting locations, and deep soil mixing using state-of-the-art Cutter Soil Mixer(CSM).

This project represents the first ever North American application of this type ofdeep soil mixing technology, and possibly the first application of this designapproach for a commercial application in an urban environment anywhere. Byconstructing soil-cement walls through the underlying loose soils and keying theminto competent ground at depth the design prevents large lateral movements ofthe liquefiable soils and provides vertical foundation support onto the underlyingtill.

Sheet #58, Project n 061-7000-031 of 1

KEY-ELEMENTS

CLIENT

City of Nanaimo, British Columbia

LOCATION

Nanaimo, BC

SERVICE

Ground improvement using rapidimpact compaction (RIC), shallowsoil mixing and deep soil mixingusing a Cutter Soil Mixer (CSM)

DURATION

March 2006 to August 2006

GAIA PROJECT VALUE

$3 Million

OVERALL PROJECT VALUE

$ 72.5 Million

KEY PROJECT PERSONNEL

- Project Director: Brian Wilson

- Project Manager: John Scholte

Through the use of innovative constructiontechniques and teaming with localcontractors and services, GAIA was ableto keep project costs down, finish onschedule and participate in the local

economy on this flagship project for theCity of Nanaimo. Golder Associates Ltd,concurrent with GAIA activities, alsoinvestigated and completed environmentalsite remediation.

With the soils successfully remediated,construction on site is moving briskly. ITC,the general contractors, report that theproject is on schedule for an anticipatedsubstantial completion in spring 2008.