【摘要】 根据放射性同位素探测到的垂向流速及示踪剂浓度变化对含水层进行了完整的分类,全面总结了稀释公式的适用性,指出对涌水含水层不能用其测得地下水水平渗透流速。论证了对具有天然水力坡度的含水层,其涌水量仍可用相关井流公式来计算。提出采用钻孔示踪技术与注水试验相结合的方法获取涌水含水层的渗透系数。首先测量天然状态下示踪剂随时间的浓度变化,计算含水层在孔中的垂向流速(包括大小及方向)、流量,然后向孔内注水产生不同的水头,得到另一种状态下该含水层的垂向流速、流量,进而求出含水层的渗透系数。分别给出了在稳定流与非稳定流状态下,计算渗透系数的表达式。该方法简单易行,同样适用吸水含水层,扩大了示踪技术的应用范围。最后将该方法应用于工程实例,并得到检验。更多还原

【Abstract】 Aquifers are fully classified according to vertical velocity and the change of tracer’s concentration de- tected by radioactive isotope in borehole, and the applicability of the dilution formula is summarized completely. It is pointed that the horizontal seepage velocity in gushing aquifer can’t be obtained by the formula. For the aquifer with natural hydraulic gradient, its discharge can still be calculated by correlative well flow formulae. A method is ad- vanced to gain the coefficient of permeability with combining tracer technique and water injection experiment in a borehole. Firstly, we can measure the concentration of the tracer in the borehole along with time in natural condition, and calculate the vertical velocity and discharge. Then, we inject water in the borehole and obtain a different level in the borehole, and gain a set of value about velocity and discharge in the state. Finally, the coefficient of permeability in the aquifer is got. Moreover, the calculating formulae concerning steady flow and unsteady flow are discussed re- spectively. This simple and practical method can also be applied to sopping aquifers as such as gushing aquifers, which extends the applied range of tracer technique. At last, the effective application of this method is docu- mented by a practical example.更多还原