海绵城市透水砖铺装雨水入渗模型及产流分析

INFILTRATION MODEL AND RUNOFF ANALYSIS FOR POROUS BRICK PAVEMENT FOR SPONGE CITY CONSTRUCTION

透水砖铺装系统的入渗特征是海绵城市建设中产流控制的重要影响因素。以海绵城市试点庄河市为例,通过渗流试验,构建不同地基层土水特征曲线,建立适用于透水砖铺装系统各层的入渗模型,揭示系统雨水入渗规律,阐明结构层厚度和地基层土壤特性对产流控制的影响。研究表明:土壤粒径对产流控制影响程度最大;特大暴雨时,粗砂土壤作为地基层,相比细砂土壤和粉质黏土作为地基层,可以延长产流时间,但随着雨强继续增大,产流时间延长作用逐渐减弱;以粉质黏土作为地基层,基层与垫层厚度比约为3 ∶2,以砂质土壤作为地基层时,基层与垫层厚度比约为4 ∶1时,透水砖铺装系统产流控制效果最好。

The infiltration characteristics of the porous brick pavement system is an important factor effecting the runoff control in the construction of sponge cities.Taking Zhuanghe,a pilot city in the sponge city constrction in China as an example,through the seepage test,the soil-water characteristic curves of different foundation layers were constructed,and the infiltration model suitable for each layer of the porous brick pavement system was established.Thus,the rainwater infiltration law of the system was revealed,and illustrating the effect of structural layer thickness and soil properties of the foundation layer on the runoff control.The results showed that the soil particle size had the greatest effect on the runoff control;when the heavy rain occurred,the coarse sand soil could be used as the foundation layer to reduce the runoff time,but as the rain intensity continued to increase,the extended runoff time gradually weakened;when the silty clay was used as the foundation layer,the ratio of the thickness of the foundation layer to the cushion layer needed to be controlled at about 3 ∶2,and when the sandy soil was used as the ground layer,the ratio of the thickness of the base layer to the cushion layer needed to be controlled at about 4 ∶1,then the porous brick pavement system runoff control effect was the best.