Probability Approach for Ground and Structure Response to GSC 2015 Seismic Hazard Including Crustal and Subduction Earthquake Sources

by Guoxi Wu, Tuesday, November 14, 2017

This presentation will provide an overview on how to make use of crustal, in-slab, and interface subduction hazard values from the 2015 GSC Model for the 13148 grid points (10 km by 10 km) in southwestern Canada (southern BC and western Alberta). USH spectra for crustal/in-slab earthquakes and USH spectra for Cascadia subduction interface earthquake can be derived at a couple of probability levels. Structure performance assessment can then be determined separately for the two main earthquake sources at a couple of probability levels. The overall probability at a given performance level (displacement, liquefaction or others) can then be determined by adding the probabilities from each of the two individual performance hazard curves.  The overall performance (displacement, liquefaction or others) at a target probability level (e.g., 2%/50 years) is then determined from the overall combined performance hazard curve. Examples for determining seismic slope displacements from empirical equations (Bray and Travasarou 2007, Macedo et al. 2017) and for assessing site response and liquefaction using nonlinear finite element time history analyses (VERSAT, Wutec 2016) will be shown to illustrate the proposed procedure. 


Advances in Dam Design - 2017 Fall Cross Canada Lecture

by Jean-Marie Konrad, Wednesday, October 25, 2017

Embankment dam performance and life span are closely related to the hydric, thermal and mechanical behaviour of materials used during its construction. The apparent simplicity of embankment dams hides complex and often poorly known behaviours resulting from thermo-hydro-mechanical coupling phenomena. Understanding the different behaviours as well as their interrelationships is of paramount importance to optimize the life cycle of these structures.

Hydro-Québec Production obtained the necessary approvals to build a 1,550-MW hydroelectric complex on the Rivière Romaine, north of the municipality of Havre-Saint-Pierre on the north shore of the St. Lawrence. The complex will consist of four hydropower generating stations with average annual output of 8.0 TWh.

Construction of the Romaine-2 development began in 2009. Romaine-2 was commissioned in 2014 and the Romaine-1 development was commissioned in 2015. Work on the Romaine-3 and Romaine-4 developments, which will be operational in 2017 and 2020, respectively is underway.

Since 2009, the NSERC/HQ industrial research chair in Life Cycle Optimization for Embankment Dams contributed to the advancement of various aspects in dam design.  Major developments for seepage induced erosion are presented.  The use of centrifuge testing for predicting deformation of Romaine 2 are discussed.  Rockfill properties are viewed from a fractal perspective.

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.