为探讨管井回灌在深基坑工程中的设计及应用,分析了基于环境控制的深基坑工程管井回灌设计的特殊性,开展了悬挂式帷幕下不同回灌滤管类型的降水回灌渗流分析及对比,探讨了影响回灌管井平面布设以及管井滤管设计的关键因素,同时针对深基坑工程回灌的特殊性,提出了"双点位流态"控制设计原则、回扬控制措施的确定方法以及回灌水质应满足的3项原则。

For the design and application of tube well recharge in deep foundation pit engineering, the analysis is made on the particularity of recharge well design for deep foundation pit engineering based on environmental control, the comparison is carried out on dewatering recharge seepage of different recharge filters for hanging curtain and the discussion is made on the key factors affecting plane layout of recharge wells and the design of tube well filter.Aiming at the recharge particularity of deep foundation pit engineering, design principles of“two points flow state” control and determination methods of the lift pump pressure control are put forward, the paper also present 3 principles that the injection water quality should meet.

针对地下水地源热泵工程回灌过程中存在铁、锰化学堵塞问题,研究了不同含量及配比的铁、锰离子在间歇回灌条件下对化学堵塞的影响。以沈阳城区为例,配制了含有不同铁、锰离子浓度的水样进行室内模拟回灌试验,对回灌前后多孔介质表面进行了SEM扫描电镜图对比。结果表明,Fe2+是影响堵塞程度的主要因素之一,其浓度越高堵塞发生时间越早且程度越严重;只存在Mn2+的试样回灌后并没有明显堵塞发生,其必须在Fe2+的协同作用下才会造成堵塞;间歇回灌会带入大量氧气使铁、锰氧化沉淀反应加快,导致堵塞加剧。回灌过程中应严格并优先控制Fe2+含量,选址时应避免高铁离子浓度的地区及铁、锰离子浓度均较高的地区,并且减少与氧气的接触,以增加回灌效率,减少洗井次数。

For the chemical clogging problem by ferrous and manganese ions in recharge of groundwater source heat pump system,studies the influence of different ferrous and manganese ion contents and ratios on the chemical clogging in intermittent recharge conditions.Taking the urban area of Shenyang as an example,conducts the laboratory test of simulative recharge process with different recharge water samples,and contrasts the SEM pictures of porous medium surface before and after recharge.The results show that Fe2+ is one of the important factors of influencing clogging degree.The higher the concentration of Fe2+ is,the earlier the clogging occurs and the more severe the degree of clogging is. There is not obvious impact on clogging with the sample that only has Mn2+ in it.Mn2+ has not obvious impact on clogging except in the synergy of Fe2+ .Intermittent recharge can bring in a lot of oxygen.That accelerates the precipitation of ferrous and manganese oxidation reaction and leads to aggravated

通过总结再生水地表入渗场地适宜性评价的相关文献发现,目前应用比较广泛的再生水地表入渗回灌方式中按回灌目的的不同可分为两种类型:一类以控制污染为目的,其中以农田灌溉方式为主,该类场地一般需要有较好的防污能力;另一类以补充地下水、获得优质回用水为目的,其中以土壤含水层处理系统为主,该类回灌场地不仅要求渗透层有很好的渗透能力,同时还要有一定的水质净化能力。以农田灌溉和土壤含水层处理系统为例,总结了不同回灌目的场地的适宜性评价模型的特征,并在此基础上提出了再生水地表入渗场地的适宜性评价模型中需要进一步研究的问题。

Based on the relevant literature,the infiltration of reclaimed water from ground surface could be divided into two classes according to the purposes. One of the purposes is to control pollution. Farmland irrigation is the main method. In general,site selection of this purpose needs high capacity to prevent groundwater contamination. The other one is to recharge groundwater in order to obtain good quality of reused water,such as soil aquifer treatment system. Site of this purpose needs high permeability and high natural attenuation ability of vadose zone. In this paper,farmland irrigation and soil aquifer treatment system were taken as examples to analyze and discuss the methods for site selection of different purpose. The question for further research was presented based on the above discussion.

人工回灌是提高水资源利用水平的重要工程措施,然而回灌过程中的堵塞问题会影响入渗效率和入渗工程的使用寿命。为了深入研究堵塞的机理,以控制堵塞问题,通过砂柱试验模拟了地下水人工回灌物理堵塞过程,通过测定含水率的变化分析了由堵塞引起的砂柱饱和非饱和状态的转化。试验中出流速率经过了迅速增大到一峰值后快速减小,然后又缓慢变小的过程,即：仅经过72 h 的回灌,砂柱的出流速率减小为2.18 m/d；72 h 后砂样出流速率的减小明显放缓；192 h 时,砂样出流速率为0.81 m/d,约为出流速率最大值的1/10。试验结果表明：回灌水悬浮物颗粒进入砂样空隙中引起渗透性减弱,和逐渐沉积在砂柱顶部形成的淤泥层是造成堵塞的直接原因,而淤泥层的形成是造成渗滤速率迅速下降的关键因素；淤泥层的弱透水性使砂样由上至下含水率发生了变化,导致了砂样导水率和水力梯度都降低,促使回灌渗滤速率迅速减小；回灌时间越长,淤泥层厚度越大,出流速率越小。由10组对比试验的结果,综合考虑引起雨洪渗滤系统堵塞的各种因素,建立了无砾石滤料雨洪水回灌过程计算渗滤速率变化的经验模型,拟合结果决定性系数为0.932。

Artificial recharge is an important engineering measure to improve the level of water resource utilization.However,the clogging in the process of injection will affect the efficiency and service life of the infiltration.In order to study the theory of the clogging and to control it,experimental sand columns were used to simulate the clogging process during groundwater artifical recharge,and the saturated-unsaturated change induced by clogging was analyzed.In the test,the outflow rate increased quickly to a peak value followed by a rapid decrease,and then decreased slowly,i.e.,only after 72 h of injection,the flow rate of sand column reduced to 2.18 m/d;the outflow rate of the sample decreased slowly after 72 h;the sample outflow rate was 0.81 m/d after 1 92 h,about 1/10 of the maximum outflow rate.The results showed that the basic reason of clogging was the permeability reduction caused by suspended matter filling the void volume of the sand and the silt layer formatted by su

实验通过对膨润土基回填材料的配比、干密度、孔隙率、含水率和环境温度等因素研究发现,膨润土基回填材料的导热性能主要是由骨料(石英砂)含量、干密度和孔隙程度共同决定的,环境温度对回填材料导热性影响较小。含水率应合理控制,适宜配比、正确回灌能有效提高导热性和地下热交换器的工作效率,工程收益率高。

Make an experiment on the influence of composition,density,porosity, water content and temperature on the borehole backfill materials.The research results indicate that the thermal conductivity of bentonite backfill material is determined by the quartz sand content,density and porosity.The thermal conductivity with temperature is slightly higher,and water content should be reasonablely controlled.Suitable composition, correct backfill can effectively improve the thermal conductivity and the underground heat exchanger efficiency,and acquire an high project benefit.