多次模拟弹射载荷作用下水泥混凝土路面动态响应

道路结构作为承载基础，与发射装备构成了动力耦合系统，冲击载荷作用下路面的响应特性将直接影响到导弹发射安全性。为研究多次弹射载荷下水泥混凝土道路结构的动态响应，以压缩空气为动力源搭建模拟弹射载荷生成装置，在三维试槽中铺筑水泥混凝土路面，面层中铺设应变传感器，土基中埋设土压力传感器，通过多次冲击加载试验获取模拟弹射载荷作用下土基压应力和面层应变变化规律，分析土基内压应力与深度及载荷作用面中心点距离间的关系，得到多次模拟弹射载荷下面层破坏形式及破坏机理。研究结果表明：冲击压力与土基峰值压应力呈线性关系；距离载荷中心点3 300 mm处，不同模拟弹射载荷下各深度处的土基压应力峰值已经非常小，模拟弹射载荷的径向影响范围为3 300 mm以内；模拟弹射载荷较小时面层为弹性变形，模拟弹射载荷增加到0.77 MPa时混凝土面层产生辐射状贯穿裂缝；弹射载荷作用下路面出现整体沉降。

Simulation of the Dynamic Response of Cement Concrete Pavement under Multiple Cold Launch Loads

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.