Abstract: As the road structure is coupled dynamically with the launching system, the impact mechanical behaviors of pavements will directly affect missile launching safety. A loading device for simulating cold launching loads is developed with compressed air as a power source. Then, an asphalt concrete pavement is paved in a three-dimensional test slot fitted with strain and soil pressure sensors. The variation laws of surface layer displacement is obtained by analyzing the response of the pavement under multiple impact loads, and the relationship between the internal pressure stress of the soil subgrade and the depth and distance from the load center is studied. The failure modes and mechanisms of the surface layer under multiple simulated cold launching loads are observed. The experimental results show a linear relationship between the impact pressure and the peak compressive stress of the soil subgrade. The peak compressive stress of the soil subgrade at different depths under different impact loads is very small at 3 300 mm away from the center of load. The surface layer is elastically deformed when the impact load is small, and radial penetrating cracks are generated on the concrete surface layer when the impact load is increased to 0.77 MPa. The cold launching load cause an integral settlement in the pavement.

Key words: cementconcretepavement, coldlaunchingload, multi-impactresponse, soilsubgradestress, surfacelayerfailure