Use of probabilistic methods in geotechnical engineeringKeynote Address

Due to the intrinsic inhomogeneous nature of soils and rocks, the minimal site investigations, and the need to extrapolate available information over a large domain, geotechnical designs have inevitable uncertainties. To be conservative, geotechnical engineers traditionally use a safety factor to account for uncertainties. A more rigorous way of considering uncertainties is to use probabilistic methods. To promote the use of probabilistic methods in geotechnical engineering, this paper tries to address the following commonly encountered questions:

1. Why do we need to use probabilistic methods?
2. How can we use probabilistic methods if we don’t have enough test data?
3. How much field/test data do we need?
4. How can we use multiple sources of information?
5. How can we use monitoring data to predict future performance?