路面不等厚排水层设计

Improved design of pavement drainage layer with varying cross-width thickness

基于饱和渗流理论,结合高速公路排水实际情况,提出一种提高排水层排水能力的设计方法。该设计方法建立面层与等厚排水层,面层与不等厚排水层之间的水量交换计算模型,获得等厚排水层不同横向位置断面处的流量计算公式和不等厚排水层不同横向位置断面处的流量计算公式,对比分析等厚和不等厚排水层的排水能力。结果表明:在排水层横向截面积相等的情况下,不等厚排水层的排水能力大于等厚排水层的排水能力。不等厚排水层的厚度渐变坡度对排水层的排水能力的提高有显著作用,其厚度对排水能力影响不显著。因此,排水材料的渗透系数以及不等厚排水层厚度渐变坡度应为不等厚排水层设计的主要控制参数。

Based on the saturated flow theory,a method was presented for improving the design of drainage layer of pavement.Meanwhile,the mathematical models were established to calculate the water exchange in drainage layer with a constant cross-width thickness and with a varying cross-width thickness respectively.Then,the analytical solutions of flux distribution in drainage layer with a constant cross-width thickness and with a varying cross-width thickness were obtained respectively to evaluate the improvement of drainage capacity of proposed drainage layer.Further,the drainage capacity of drainage layers was analyzed.The results show that the drainage layer with a varying cross-width thickness can improve the water drainage capacity well compared with the drainage layer with a constant cross-width thickness for the same cross-section area.Moreover,the parameter n（i.e.,slope of drainage layer with a varying cross-width thickness） plays a significant role in improving the drainage capacity of drainage layer,while the parameter H＇（thickness of drainage layer） has no obvious effect on the drainage capacity of drainage layer.Therefore,the permeability of drainage material as well as the slope of drainage layer should be the key controllers for the design of drainage layer with a varying cross-width thickness.