Research on Frost Heave Deformation of Subgrade in Alpine Meadow Area under Different Freezing Modes

In order to study the frost heave deformation characteristics of subgrade soil of GongjueMangkang highway in alpine meadow area under different freezing modes,the frost heave deformation characteristics of subgrade soil under unidirectional freezing and surrounding freezing are analyzed based on indoor frost heave test.The test results show that there is a positive correlation between soil moisture content,fine particle content and frost heave deformation rate;under the same moisture content and fine particle content,the frost heave rate of soil under surrounding freezing is greater than that of unidirectional freezing;when designing subgrade soil gradation in practical engineering,the initial moisture content should be controlled at the optimum moisture content of about 8%,and the content of fine particles in soil should be controlled at about 9%;under unidirectional freezing,the initial moisture content and fine particle content in the soil significantly affect the frost heave deformation rate of the soil,and the initial moisture content has a more significant effect;and under surrounding freezing,the initial moisture content significantly affects the frost heave deformation rate of soil,but the content of fine particles has no significant effect on the frost heave deformation rate of soil.