Probabilistic assignment of design undrained shear strength using quantile regression.

In offshore geotechnical site characterization, it is common practice, for subsequent design of foundation systems, to characterize lower- and upper-bound design profiles to address bearing capacity and penetration resistance, respectively. Such profiles are most often assigned subjectively from penetration data using engineering judgment. Subjective assignment does not allow the direct assessment of the associated probability of exceedance. Quantile regression is a statistical method which allows the assignment of regression functions which are directly and quantitatively associated with levels of exceedance. The paper provides an example application of quantile regression to Undrained shear strength profiles from an offshore site. The benefits of this technique in a geotechnical engineering framework are discussed.