Study on mechanical behavior of non-wettable sands

It is well known that the existence of meniscus water affects the shear strength for unsaturated soils. Although natural soils exist as wettable (hydrophilic) soils generally, it is possible that the natural soils become non-wettable (hydrophobic) soils due to an organic pollutant, natural hazards such as forest fire, and environmental pollution accidents such as oil spill. The non-wettability in soils affects physio-mechanical behaviors, the contact angle and the capillary pressure. The accumulated geotechnical knowledge so far tends to be somewhat limited to wettable soils in the field of unsaturated soil mechanics. Among several research subjects for hydrophobic and hydrophilic sands, this paper presents the empirical verification on which the existence of meniscus water affects the shear behavior for unsaturated soils using artificially synthesized hydrophobic sands. In addition, the obtained shear strengths are discussed by means of the application of the suction stress.