对偶反滤回灌井室内稳定流试验研究

Research on the Laboratory Steady Flow Test of Dual Recharge Well with Filter Layer

反滤回灌井是山东半岛地下水回灌中常用的回灌设施,它由普通回灌井和回灌池组成。在分析现有反滤回灌井存在问题的基础上,设计了3种新型对偶反滤回灌井,研制了室内稳定流回灌试验装置,进行了普通回灌井、现有反滤回灌井和3种对偶反滤回灌井的室内稳定流回灌试验,分析了回灌井口类型对单井回灌量的影响。得出以下结论：对偶回灌井口的不透水下壁,可防止雨洪初期劣质水回灌含水层;如果在对偶回灌井口外套一层土工膜,则可预防污染河水回灌含水层。在试验条件下,同现有反滤回灌井相比,对偶反滤回灌井的单井回灌量增加了395%~414%,并具有较强的抗冲能力。反滤回灌井初次回灌试验的单井回灌量最大,随回灌试验次数的增加,其单井回灌量逐渐减小,并趋向稳定。回灌井口类型影响单井回灌量,与方形和台形对偶回灌井口相比,圆形对偶回灌井口进水水流流态较好,单井回灌量较大。

Recharge well with filter layer is a common device used for recharging groundwater in Shandong Peninsula, and it is com- posed of recharge well and recharge pool. By analyzing the problems of existing recharge well with filter layer, three dual recharge wells with filter layer are designed, the laboratory steady state flow recharge test device is developed, an experimental study is con- ducted on laboratory steady state flow recharging of the ordinary recharge wells, the existing recharge well with filter layer and three dual recharge wells with filter layer, and the effect of the shape of wellhead on single-well recharge volume was also analyzed, draw the following conclusions： The lower impervious wall of dual recharge wellhead which can prevent inferior water from flowing into aquifer when water level was lower at beginning stage of rainfall flood; covering geomembrane on external wall of dual recharge well- head which prevent polluted river water from recharging into aquifer. At the same experiment conditions, compared to the existing recharge well with filter layer, the single-well recharge volume of dual recharge wells with filter layer had increased 395%~414%, and the dual recharge wells also had stronger anti-rush capability. The single-well recharge volume of recharge wells with filter layer was the largest in the first test, and decreased with an increased in test times, then tend to be stable. Round dual recharge wellhead had a better inlet flow pattern and a bigger single-well recharge volume compared with square dual recharge wellhead and square table dual recharge wellhead, since the shape of recharge wellhead affected single-well recharge volume.