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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。
In order to realize the rapid and effective drainage of pavement structure, a new type of pavement drainage system using composite geosynthetic drainage material is proposed based on unsaturated seepage theory. The system consists of three parts: hydraulic conducting layer, capillary impervious layer and isolation Floor. A new type of pavement drainage system model test and numerical simulation analysis were carried out to study the performance of a new type of pavement drainage system under rainfall infiltration conditions. The model test was conducted to measure the change of suction of subgrade and subgrade in real time by setting tension gauges in the grassroots and subgrade respectively. The method of controlling variables is established and numerical analysis model considering unsaturated seepage is established. The influence of the location, thickness and slope of the new pavement drainage system on drainage performance is analyzed. The results show that the new type of pavement drainage system can quickly and effectively eliminate the infiltration water, and the base material is in a non-saturated state during the test, and the substrate suction of the grass roots starts to pick up 10 minutes after the rainfall stops. The new pavement drainage system can prevent water infiltration To the embankment, the suction of subgrade soil in the process of rainfall is always kept at the initial suction value. When the new type of pavement drainage system is adopted, the water vapor content of grassroots unit increases continuously during the rainfall but does not reach the saturated volumetric water content. After the rainfall stops, Showing a slight decline in subgrade moisture content remained unchanged; between the surface layer and the grass-roots level, grassroots and roadbed between the new road drainage system is more conducive to control the grass roots suction and volumetric water content; increase the thickness of the new road drainage system and The slope can reduce the water content of grassroots materials to a certain extent and improve the bearing ratio of grassroots. The research results can provide a theoretical basis for the application of the new pavement drainage system engineering.