The freezing-thawing experiments were performed to investigate the effect of pre-freezing moisture content and dry density on the compression and water migration in Qinghai-Tibet silty clay under double-direction freezing and one-direction thawing. The results show that (1) under large thermal gradients

the compressibility of the soil decreases at low initial densities and increases at high initial densities after freeze-thaw cycles

whereas under small thermal gradients

the soil compressibility constantly decreases; (2) As the pre-freezing moisture content increases

the soil compressibility under larger thermal gradients increases and approaches to a stable value

whereas it remains practically unchanged under small thermal gradients; (3) As the thermal gradient increases

all the compressibility coefficients of melted soils at different densities decrease first

and then increase

and the compressibility coefficients of melted soils under different pre-freezing water contents increase; (4) The water contents in the frozen specimen first increase

then decrease and finally increase from the top to the bottom. As the thermal gradient descends

the water content in the middle part of the specimen increases first and then decreases.