湿陷性黄土地区一种雨水收集装置——埋深对变形影响的试验研究

Experimental study on the effect of buried depth of a rainwater collecting device on deformation in collapsible loess area

黄土地区城市建设,地面雨水集中补充地下的过程中极易诱发黄土湿陷,产生局部不均匀沉降,引起地面塌陷并威胁周边建筑物安全。针对湿陷性黄土地区城市建设,设计了一种路面雨水收集补充地下水系统,采用透水混凝土转移雨水,利用土工膜和三七灰土的弱透水性阻止雨水与湿陷性土层接触,通过蓄水结构收集、存储雨水,多余水量过滤后经砂井导入地下,以削弱雨洪峰值,避免湿陷和土壤干化等问题。根据现场试验,研究了砂井埋深与变形的关系,得出较大埋深可以减缓水分到达土体的时间,同时减少变形的结论,从而服务于黄土地区海绵城市建设。

The process of urbanization changes the conditions of infiltration of the original ground,causing the problems of urban waterlogging and dry groundwater.Sponge City is to make full use of the functions of building,roads,green spaces and water systems to absorb,store and release rainwater.It can achieve natural accumulation,infiltration and purification by effectively control surface runoff.To develop sponge city in the loess area will face local loess collapsibility caused by concentrative infiltration,result in collapse and uneven settlement,and threaten the safety of surrounding buildings.Based on the theory of transferring adhesive water and the principle of soil water potential,a rainwater harvesting and drainage system is designed to adapt to the application of the Loess area,which can use porous concrete to transfer rainwater.Simultaneously,the weak permeability of geomembrane and the lime soil is used to prevent rainwater infiltrating into collapsible soil strata.Then storage structure collect rainwater,the rest of quantity is filtered and then drain off by drainage structure to reduce the peak of rain and to avoid problems such as collapsibility and soil drying.According to the field test,the relationship between the deep and deformation of the sand well was studies,which shows that the larger burial depth can slow down the time of water to reach the soil,and reduce the deformation.