Effects of Drying and Wetting Cycles on the Shrinkage Characteristics of Loess in Landslide Area
The purpose was to investigate the shrinkage characteristics and regularity of collapsible loess during drying process in the loess landslide disaster area in the northern foothills of Mt.Tianshan,China.Based on the shrinkage tests of three soils with different initial moisture content under 9 cycles of drying and wetting,the relationship curves of shrinkage rate and moisture content with cycling time were obtained.By fitting the similar trend of soil shrinkage curve under different cycles,the equations of loess shrinkage curve under different cycles in this area were obtained,the results show that the linear shrinkage of a certain moisture content is exponential with the number of cycles,and the final linear shrinkage decreases with the increase of the number of wet and dry cycles.The linear shrinkage of soil occurs mainly in the stage of linear shrinkage,and the linear regression equation which characterizes the relationship between the number of drying and wetting cycles and the shrinkage coefficient is obtained by fitting this stage.Results show that the contraction coefficient decreases with the increase of cycle times,and they show a good exponential relationship;The dehumidification deformation of loess can be divided into crack deformation and shrinkage deformation.The law of surface crack of soil sample under drying and wetting cycle is analyzed by PCAS software.It is concluded that the cracks appear at the edge of the specimen in the first three cycles,and the cracks and shrinkage deformations are obvious in the fifth cycle,and the shrinkage deformations enter a stable state after the seventh cycle.
loess in landslide area of northern foothills of Mt.Tianshandrying and wetting cycleshrinkage characteristicsPCAS image processing
万方数据
维普
