车载引起的沥青路面内动水压力现场试验研究

为了研究移动车载引起的动水压力对沥青路面水损坏产生的影响,探究路面层内动应力变化及动水压力的长消规律,利用自主研制的耐高温动应力和动水压力传感器,对现场行车荷载引起的动应力及动水压力进行实测,获取了动水压力的实测数据;并且基于Biot固结理论,利用一种反映移动效应的车轮荷载数值模拟方法,对实测工况下路面情况进行了动态流固耦合分析,定量研究了路面层内的动水压力长消规律。发现现场实测与数值模拟结果基本一致。沥青路面在周期行车荷载作用下,路面空隙中不断产生动水压力的泵吸作用,导致沥青混合料强度下降,进而引发水损坏。该成果验证了水损坏的水力驱动机理,为水损坏研究和路面设计提供了借鉴。

Field test and research on vehicle load induced dynamic pore pressure in asphalt pavement

In order to study the influence on moisture damage of asphalt pavement caused by dynamic pore pressure due to moving vehicle loads, and explore the time histories of dynamic stress and dynamic pore pressure in the pavement surface layers, the heat-resistant dynamic stress and pore pressure sensors were developed and used to measure the dynamic stresses and pore pressures in the field, and the field measured data of dynamic pore pressure was acquired. Based on the Biot's consolidation theory, a numerical fluid-solid coupling simulation method reflecting mobile effect of wheel load was used to analyze the response of pavement under the actual condition. The time history of dynamic pore pressure in pavement was quantitatively analyzed. Numerical simulation results matched well with in situ test data. The pump-suction effect of dynamic pore pressure that continuously generated in pavement void under cyclical vehicle loads led to the reduce of the asphalt-aggregate bond strength and further triggered the moisture damage. This study verified the hydraulic drive mechanism of moisture damage, and provided a theoretical guild for the moisture damage research and pavement design.