Development of a geotechnical design standard for buildings in Canada

Canadians are in the enviable position of having created a world-leading reliability-based geotechnical design code for bridges, namely Section 6 Foundations and Geotechnical Systems of CSA S6:19, Canadian highway bridge design code (CHBDC). Further research is now required to develop similar design provisions for the buildings, where a minimum geotechnical standard is currently lacking in Canada. It is anticipated that such design provisions would be beneficial and could be considered for a future standard.

This report summarizes the findings of a study that investigated target reliability levels for geotechnical systems and the resulting resistance factors required to achieve these reliability targets within a load and resistance factor design (LRFD) framework. The geotechnical problems considered include:

Seismic design of deep foundations;
Seismic and wind loading design of shallow foundations;
Sliding resistance of shallow foundations; and
Sliding and overturning resistance of retaining walls.
This report also summarizes the results of an investigation into direct reliability-based design as an alternative to the LRFD approach.

While most of the unknown resistance factors needed to develop a geotechnical design standard for buildings in Canada are calibrated in this report, areas that require additional research for the calibration of geotechnical resistance factors are identified in the summary.