Evergreen LINE RAPID TRANSIT: dEEP FOUNDATION AND GROUND IMPROVEMENT SOLUTIONS - aND ANNUAL GENERAL MEETING
by Ali Azizian, September 20, 2017
The 11 km long alignment of the Evergreen Line Rapid Transit (ELRT) project through Burnaby, Coquitlam and Port Moody consists of elevated and at-grade guideway sections as well as cut-and-cover and bored tunnels. Because of the high seismicity of the region, liquefiable and soft soils posed the main challenges for the design of structures. A performance-based design approach with varying levels of performance requirements were specified for the project. Several deep foundation and ground improvement solutions were used to meet the design objectives, while satisfying cost, schedule and site constraints. Foundation types included drilled shafts and driven steel pipe piles. Ground improvement solutions included Cement Deep Soil Mixing (CDSM) and driven timber piles. The presentation will provide an overview of the subsurface ground conditions along the alignment, seismic analyses (e.g. FLAC modelling), selected foundation or ground improvement types for each section, and some of the challenges faced during construction.