松散岩类承压含水层影响半径计算方法

发布时间：2018-11-08 15:46

【摘要】：在研究地下水污染修复、确定群井抽水的井间距、矿坑涌水量和渠道排水等问题时,需要采用稳定流公式进行相关参数的计算。在稳定流公式中,当抽水试验的观测井数量大于2时,计算的影响半径和含水层参数是比较接近真实值的。但在实际工作中,很少有抽水试验设专门观测井,因此只能利用单井抽水试验非稳定流的影响半径公式进行求参,然而该时间变量函数包含了多个未知参数。为了简化影响半径的计算方法,将函数中的抽水稳定时长t和贮水系数μ*用工程试验的经验值进行替换,得到一个影响半径与含水层导水系数的简单函数,然后将Dupuit公式中的影响半径用此函数替代,最后通过牛顿迭代法能够同时得到影响半径和含水层导水系数的值。利用该简便公式计算的影响半径值与带2个观测井的Dupuit公式和Theis公式计算的值进行对比,发现误差都在可接受范围之内,并且该值与Modflow水流模型模拟的抽水试验最大影响半径接近。因此,可以认为该简化后的影响半径公式适用于松散岩类承压含水层抽水试验求参。
[Abstract]:In order to study the problems of groundwater pollution remediation, well spacing, pit discharge and drainage, it is necessary to use the formula of steady flow to calculate the relevant parameters. In the steady flow formula, when the number of observation wells in pumping test is more than 2, the calculated influence radius and aquifer parameters are close to the true values. However, in practice, there are few special observation wells in pumping tests, so the parameters can only be obtained by using the influence radius formula of unsteady flow in single well pumping test. However, the time variable function contains many unknown parameters. In order to simplify the calculation method of the influence radius, the pumping stability time t and the water storage coefficient 渭 * in the function are replaced by the experimental values of the engineering test, and a simple function of influencing the radius and the water conductivity of the aquifer is obtained. Then the influence radius in Dupuit formula is replaced by this function, and the influence radius and aquifer conductivity can be obtained simultaneously by Newton iteration method. The influence radius calculated by this simple formula is compared with the values calculated by Dupuit formula and Theis formula with two observation wells. It is found that the errors are within the acceptable range. And this value is close to the maximum influence radius of pumping test simulated by Modflow model. Therefore, it can be considered that the simplified formula of influence radius is suitable for pumping test of loose rock confined aquifer.
【作者单位】：中国地质大学(北京)水资源与环境学院;中国地质环境监测院;中国地质调查局水文地质环境地质调查中心;河北地质大学;
【基金】：国土资源部公益性行业科研专项(201411074,201411083) 中央财政专项(1210800000022)
【分类号】：P641.73

【相似文献】