Mechanical properties of clay reinforced with Bermuda grass root under drying–wetting cycles

Abstract

The mechanical properties of the clay slope gradually weaken after the drying–wetting (D–W) cycles, which increases the possibility of landslides. Therefore, the variation of mechanical properties of the root–soil composite during D–W cycles was studied in this paper. Through unconsolidated undrained triaxial test (UU test), the effect of D–W cycles on vegetation slope engineering under different confining pressures was studied. UU tests measured the shear strength parameters of the root–soil composite after each cycle. The results show that under different D–W cyclic numbers and confining pressures, with the increase of axial strain, the deviatoric stress increases sharply at first\xa0(elastic stage). Then grows slowly (elastopplastic stage)\xa0and finally decreases gradually\xa0(failure stage). After D–W cycles, the weakening trend of shear strength parameters (including cohesion and internal friction angle) of the root–soil composite is the same, while the weakening ratio of cohesion is higher than that of internal friction angle. Among them, the weakening range of cohesion and internal friction angle is 48.1% and 5.4%, respectively. Also, with the increase of D–W cyclic numbers, both of them decrease linearly.