Geotechnical problems and case histories from the perspective of unsaturated soil mechanics

This document consists of three major parts. In the first part, a total of eight and nine papers under the themes "Geotechnical problems" and "Case histories" are highlighted, respectively. In the second part, some state-of-the-art (SOA ) findings revealing non-liquefied slide and liquefied flow mechanisms of man-made loose fill slopes are presented. These findings are based on a series of comprehensive triaxial tests on saturated and unsaturated loose decomposed geomaterials and centrifuge model tests conducted on loose and dense fill slopes. In the last part, some SOA findings on possible landslide triggering mechanisms of a natural hillslope are described and reported. These findings are obtained from laboratory and field tests and a comprehensive field monitoring programme of a natural saprolitic hillslope (decomposed tuff) in Hong Kong. The field monitoring programme is designed specifically to investigate the influence of two constitutive variables (i.e., matrix suction and net stress) on the natural hillslope. The responses of the hillslope subjected to the interaction between matrix suction and net stress resulting from seasonal climatic variations are explored and discussed in this paper.