In order to analyze the stability of soaked subgrade filled with weathered phyllite

wetting deformation and resilient modulus of the subgrade are tested in field at Ankang eastern section of Shiyan-Tianshui expressway. Based on physico-mechanical property analysis of weathered phyllite

filling scheme of subgrade is put forward: for subgrade filled material with weathered phyllite California bearing ratio (CBR) >3%

the weathered phyllite is filled into the subgrade directly; for CBR<3%

the weathered phyllite is filled into the subgrade after improved with additive 3% cement. Through bearing plate field tests before and after immersion on the test road

the influence of soaking amount

soaking time on wetting deformation

rate of wetting deformation and resilient modulus of subgrade are analyzed. Combined with water content test of the test points in different depths

relationships between water content

seepage depth and wetting deformation are analyzed. The results indicate that soaking amount and soaking time are key factors that affect the seepage depth and water content; the wetting deformation of soaked common subgrade is more obvious than that of soaked improved subgrade. When both soaking amount and soaking time are equal

the resilient modulus attenuation of common subgrade is larger than that of improved subgrade.