Stability Analysis on Highway Slopes in Rainy Region

Rainfall infiltration is an important factor affecting slope stability. To investigate the influence of rainfall on highway slope stability, a typical cut slope of highway in rainy region has been adopted for the study. Based on saturated - unsaturated seepage theory and coupled solid-liquid analysis, the features of seepage, pore-water pressure, stress and displacement of the highway slope are analyzed under two different rainfall intensity and duration conditions. At the same time, modified Mohr-Coulomb strength criteria and 2-D limit equilibrium method are used to calculate the safety factors of the slope. The results showed that the range of unsaturated zone decreased, while the transient saturated zone enlarged, the pore-water pressure, displacements and the negative shear stress on the surface of the slope rose with increasing rainfall intensity and duration. The safety factors of the slope also decreased with rising of the rainfall intensity and duration and were all lower than 1.0. To mitigate, anchor-shotcrete reinforcement with adhesive bolt suspended net was applied to the slope. The results from field monitoring showed that the reinforced slope is stable even after continuous heavy rain. Therefore, anchor-shotcrete reinforcement is a useful method for strengthening slopes in rainy regions.