【摘要】 为实现路面结构快速有效排水,基于非饱和渗流理论,提出采用复合土工合成排水材料的新型路面排水系统,该系统由三部分组成,从上而下依次为水力传导层、毛细防渗层和隔离层。开展了新型路面排水系统模型试验和数值模拟分析以研究降雨入渗条件下新型路面排水系统性能;模型试验通过在路面结构的基层和路基分别设置张力计,实时监测基层和路基基质吸力变化;采用控制变量方法,建立考虑非饱和渗流的数值分析模型,分析新型路面排水系统设置位置、厚度、坡度对排水性能的影响。研究结果表明:新型路面排水系统可将入渗水快速有效排除,基层材料在试验过程始终处于非饱和状态,并在降雨停止后第10min基层的基质吸力开始回升;新型路面排水系统能够防止水下渗至路基,降雨过程中路基土的吸力始终保持在初始吸力值;采用新型路面排水系统时,基层体积含水率在降雨过程中不断上升但未达到饱和体积含水率,在降雨停止后基层体积含水率呈现小幅下降,路基体积含水率则保持不变;在面层和基层之间、基层和路基之间均设置新型路面排水系统更有利于控制基层吸力和体积含水率;增加新型路面排水系统厚度和坡度可在一定程度上减小基层材料的含水量,提高基层承载比;研究成果可为新型路面排水系统工程应用提供理论依据。更多还原

【Abstract】 In order to ensure the fast and effective drainage of pavement structure,a new drainage system of pavement structure made up of geocomposite drainage materials was proposed based on unsaturated seepage theory,including the hydraulic transport layer,capillary barrier layer and isolation layer from top to bottom.The model test and numerical simulation analysis of new pavement drainage system were carried out to investigate the drainage performance of new pavement drainage system under the condition of rainfall infiltration.In the model test,tensiometers in the base and subgrade monitored the suction change.An unsaturated seepage numerical analysis model was established to analyse the effects of thickness,slope and position of new drainage system on the drainage performance of pavement structure by the control variable method.The results show that water seeping through the pavement is drained away quickly andeffectively by new drainage system.Base material has always been unsaturated in the whole test process and base suction starts to rise ten minutes after the rain stops.The new drainage system can prevent the water infiltration to subgrade with subgrade suction keeping at the initial value.In terms of the new drainage system,the volumetric water content of the base increases constantly in the rainfall without reaching the saturation volume moisture content.After the rain stops,the volumetric water content of the subgrade decreases slightly while the volumetric water content of subgrade remains the same.The construction of new pavement drainage systems between surface course and base,base and subgrade respectively has advantage of controlling the suction and volumetric water content of base.The water content of the base material decreases and the bearing capacity of the base increases to a certain extent with the increase of the thickness and slope of the new drainage system.The results provide the theoretical basis for application of the new pavement drainage system.更多还原