Study On Design And Application Of Porous Asphalt And Bioretention Combined System

This paper studies two parts:the mechanism of permeable pavement runoff, drainage systems design and hydrology design of the permeable pavement-bioretention combination system; experimental research of the enrichment migration law of deicing salts in the bioretention facilities.The first part of the study obtained the following results:(1)This chapter first describes the mechanism of permeable pavement runoff, and the runoff coefficient of drainage type permeable pavement are discussed. Ranieri model is introduced and example applications Ranieri model for larger longitudinal sections of permeable pavement design. The interior drainage system of the permeable pavement design is studied.(2)The connection types of permeable pavement-bioretention combination systems are classified and compared, and proposed a simplified model of different connection types, combined permeable pavement and bioretention hydrological models, a hydrologic analysis model of the combination system can be built.(3)The design idea of the permeable pavement-bioretention combination system based on optimal control effect has been put forward.The second part of the experiment the following conclusions:(1)Resulted in a significant increase in the use of deicing device planted in the soil and the dielectric layer deicing salt. With increasing soil depth, deicing salt content increased slightly before, after significantly reduced,10-20cm deicing salt content in the soil was slightly lower than in the shallow soil0-5cm, which is much higher than40cm of the dielectric layer deicing salt content;(2)As the cumulative number of experiments, the soil column of different dielectric materials in the sodium ion content of each sampling point were elevated to some extent, the trend remained elevated after the first drop, and deicing salt is still mainly the rich set in the planting depth range of0-20cm soil. Contrast media of different thicknesses slag soil column, obtained in each experiment sodium content of the sample points at the same depth with increasing thickness of the slag layer is reduced;(3)Comparison of slag, sand and soil column three types of dielectric material original soil in the early spring watering analog sodium ion content of each sampling point after the experiments, watered leaching the role of the soil column will appear in the deicing salt down phenomenon, in the same medium as the water poured slag planting soil in the soil column deicing easier leached out, indicating the stronger permeable soils, deicing salt accumulated in the soil more susceptible to shower wash;(4) The amount of deicing facilities sown exchange surface conditions under30g per square meter, at the annual snowfall-the rain period, in order to deicing salt slag and sand as a medium layer and not located inside the aquifer bioretention after all of the facility will continue to be enriched leaching facility exclusion process, but in the winter and early rainy about this time, will accumulate a large amount of deicing salt, plant growth will be affected.