Experimental investigation on the settlement of fills under saturated and unsaturated conditions

The aviation industry in mainland china is growing rapidly and to cater to this growing demand numerous airports have been planned and constructed in the hilly and mountainous regions of mainland China. The formation of the airport is commonly based on a high embankment. The filling material for the high embankment possesses large self-weight and experiences seasonal variation in water content and temperature, and various external loadings. The variation in water content renders the fill material to be unsaturated. This paper presents the experimental results obtained by performing a series of tests on a poorly-graded sandy gravel using a newly designed suction controlled oedometer apparatus. Special emphasis is given to study the stress-strain behavior of fills for different stress paths. Particularly, the creep behavior of fills is investigated under different stress state variables. The results show that the matric suction increases the soil strength until the plastic deformation state is reached. Several important observations and findings from the study are presented and discussed in detail.