Geotechnical Risk Management and Reliability Based Design-Lessons Learned

Effective management of geotechnical risk is a requirement for successful geotechnical engineering design. The paper presents a brief overview of the development and current implementation of reliability based codes in Canada for foundations and geotechnical systems. Implementation challenges such as selection of suitable target reliability index, appropriate selection of geotechnical characteristic values, and geotechnical resistance factors for uplift resistance due to frost action are described through project examples. Lessons learned are identified and discussed. Lack of sufficient understanding of fundamental concepts, training and education are factors that contribute to the identified implementation issues. Reliability based design is not meant to be a substitute for good understanding of geology, geological processes, fundamental ground behaviour, failure mechanisms, and engineering judgement and experience. The paper demonstrates that enhanced effective risk management is obtained through close collaboration between the owner and their consultant.