Variation of Matric Suction in Unsaturated Loess Soils

摘要

It is well-known that natural loess soil occurs in unsaturated state.Hence,its shear strength is largely controlled by the matric suction presented in the unsaturated soils.To explore variation characteristics of matric suction within loess soils and its influencing factors apart from moisture content,an experimental study was performed using the loess soils collected from Lanzhou city,China.The results showed that structure,mineral compositions and soluble salts were the most important three factors controlling the variation of the matric suction in the loess soils.It seems that variation of the matric suction,particularly the residual moisture content,had inverse correlations with density of the soils,the abundance of interlayered smectite and illite (I/S) within the soils,while they had somewhat linear relations with abundance of soluble salts present in the soils.