Research conclusions:(1)The single-slop is the mostly type of the rocky heap in the projection，anchor pile is the main reinforcement measure of the unstable rocky heaps caused by the subgrade engineering: ( 2 ) There is a layer of low liquid limit clay folder gravel on top of the rocky heap,and lower stone soil folder low liquid limit clay on the bottom，it has obvious layered characteristics，the interface of the soil-rock and the different soil layer are the mostly potential sliding surface:(3)The groundwater is well developed，the drainage of slop and underground water of the rock heaps should be strengthened:(4) The research results can provide references for the similar projects.