Based on one-dimensional freezing test at five different top cooling temperatures in an open system

the freezing behaviors of the saturated Qinghai-Tibet silty clay are studied experimentally. Combining with digital image acquisition technology and routine data measure system in laboratory

the temperature distribution and development

cryostructure profile development

frost heave development

water supplement process and water content profile are analyzed during one-dimensional freezing of soil sample. Some conclusions are drawn as follows. Firstly

the freezing front in sample reaches a stable state after 26 hours. After that

the longitudinal cryostructure of soil samples can be divided into four belts

including tiny thin layer structural belt

thin layer structural belt

thick layer structural belt and overall structure belt from the cold end to warm end. The frost heave development contains three stages

i. e. fast frost heave stage

stable frost heave stage and linear frost heave stage. The ice lens segregation at the bottom of thin layer structural belt and thick layer structural belt are the main source of frost heave. After tests

the water content profiles of the soil sample indicate that the water content increases in frozen part and decreases in unfrozen part. Meanwhile

the layers in which having the highest water content are located at the location of thick ice lenses. Because of the consolidation of the unfrozen part and water migration from unfrozen part to freezing front and frozen part

the water content of the unfrozen part has decreased and induced a drying phenomenon. The conclusions have provided the dynamic processes of the development of cryostructure and frost heave of the Qinghai-Tibet silty clay under one-dimensional freezing. It is expected that this study will provide a test basis for future study of more reasonable frost heave models.