The causes necessitating slope protection for high highway embankments include:
- The foundation beneath the roadbed consists of an unstable natural sliding mass;
- The slopes on both sides of the highway are excessively steep;
- The embankment was constructed using an improper method of inclined layering;
- The soil is excessively moist, thereby reducing its cohesion and internal friction;
- The toe of the slope has been eroded by water.
- Instability in specific rock sections-arising subsequent to highway construction-particularly occurs when rock strata dip toward the road cut and are subsequently subjected to the destructive effects of water or seismic activity.
- The inherent geological structure and composition of the mountain slopes adjacent to the highway are unstable.
- Damage caused by debris flows.