Research on the Failure Mechanism and Prevention Technology of Loess Railway Embankment Landslide
On July 20,2021,Henan Province experienced an extreme rainstorm,triggering numerous subgrade water damage incidents. Through on-site investigations of subgrade water damage,the re-gional topography,geomorphology,and hydrogeological conditions within the affected area were iden-tified. A failure mode for loess embankment landslide was proposed,and the failure mechanism of the embankment landslide was analyzed through numerical simulations. The prevention technology of mul-tiple segmented control grouting with perforated steel pipes was used to stabilize the embankment slope. Excavation investigations and high-density electrical methods were used to explore the grouting effectiveness of perforated steel pipes in reinforcing the loess embankment,and numerical simulations were used to analyze the stability of the loess embankment slopes before and after grouting reinforce-ment. The research results indicate that:(1) Embankment landslides differ from superficial slope sur-face slides,often caused by low-lying terrain at the slope foot where precipitation accumulates at the foot or lower part of the embankment slope,soaking and softening the embankment slope,resulting in insufficient shear strength of the slope and causing landslides. (2) The numerical simulation results indi-cate that the depth of accumulated water at the slope foot has no significant effect on the vertical stress field of the embankment slope but significantly impacts the horizontal stress field and displacement field of the side slope with accumulated water. As the depth of accumulated water increases,the maxi-mum shear strain value of the embankment slope increases,and the stability coefficient decreases. (3) Excavation investigation and high-density electrical method results indicate that the perforated steel pipe grouting technology achieves good splitting grouting results in the loess strata,filling the internal pores of the loess slope with cement slurry,thereby isolating the internal water flow channels and sup-pressing internal water erosion. (4) The numerical simulation results after the perforated steel pipe grouting reinforcement indicate that the stability of the embankment is significantly improved. The re-search results provide a reference for the railway system engineering department in water damage pre-vention and control work.
subgraderailway water damageembankment landslidefailure mechanismprevention technology