In frigid area

with heaving bottom

slope protection project will be uplifted or pushed by ice force. Thus slope protection project will be damaged. Polystyrene board can protect the soil base from the negative temperature

and improve ground temperature

minish freezing depth

weaken frost heave. Through the test of physico-mechanical and freeze-thaw properties of polystyrene board

the effect of bulk density

water content

thermal conductivity

compressive strength

frost-thaw cycle times on insulation is analyzed. At last

an anti-freezing design method of slope protection project is proposed.