砂石渗井在黏土地区海绵城市建设中的应用

随着社会和经济的发展,建筑物、硬化路面等不透水结构逐渐取代了大量原始天然地面,从而造成了雨水入渗面积的迅速减少和由此引起的严重城市内涝。为解决我国水资源短缺和城市季节性洪水的双重危害,提供了一种以砂石等渗透性强的粗骨料作为内置材料的黏土地层竖向增强体渗透装置。当出现强降雨时,地表径流将汇流于密布的砂石渗井中,然后沿井壁向四周的土层中渗流。由于井壁的面积远远大于井口的面积,且一般情况下黏土的水平渗透性大于其竖向渗透性,因而砂石渗井能大大增大雨水的下渗速度。进行了填充料和岩土介质的渗透测试以及在此基础上的单井和群井现场原位试验和相应的数值模拟。结果表明:该装置经济、施工简单、效果明显,是一种环境友好型低影响海绵城市建设方法,为黏土地区海绵城市建设提供了一条有效途径。

Application of sand and stone seepage wells in sponge city construction of clay area

With the development of society and economy, impervious structures such as buildings and hardened pavement gradually replace a large number of original natural ground, resulting in a rapid reduction of rain infiltration area and urban waterlogging. In order to solve the dual hazards of water shortage and seasonal urban flood in China, a vertical seepage device with sand and aggregate as internal material in clay layer was proposed. When heavy rainfall occurs, surface runoff will converge in densely packed sand seepage wells, and then seep along the wellbore into the surrounding soils. Because the area of shaft lining is much larger than that of wellhead, and the horizontal permeability of clay is generally greater than its vertical permeability, sand and stone seepage wells can greatly increase the infiltration rate of rain water. The permeability of sand and stone seepage wells with filling materials and geotechnical media was tested, based on which, the in-situ test and numerical simulation of single and group wells are established. The results showed that the device is economical, simple and effective, and it is an environment-friendly and low-impact sponge city construction method, which provides an effective way for the construction of sponge city in clay areas.