台兰河地下水库辐射井抽水过程的非稳定渗流场的有限元分析

针对台兰河地下水库大口径辐射井抽水效果的数值模拟问题，在分析了大口径辐射井渗流行为基础上，提出了应用辐射井子结构法和子结构开关器等辐射井精细模拟技术，并联用改进的截止负压法、迭代增量法和求解大型稀疏矩阵的预处理共轭梯度算法进行有辐射井影响的地下水非稳定渗流场的有限元分析。应用自主研发的三维可视化渗流有限元计算软件GWSS对台兰河地下水库辐射井抽水试验过程中的非稳定渗流场进行了数值模拟研究。研究结果表明：所有观测井计算水位的平均绝对误差为0.22 m，单井水位的平均误差最大值为 0.40 m，最小值为0.02 m，各观测井地下水位的模拟值与实测值的变化趋势吻合较好。经验证算法的合理性和程序的可靠性较好。提出的辐射井子结构法可以精细模拟辐射井的渗流行为和局部精细渗流场，可用于分析辐射井抽水过程中的地下水非稳定渗流变化及取水效率评价。

Finite Element Analysis on Unsteady Seepage Field of Groundwater Reservoir of Tailan River During the Pumping Water of the Radiation Well

With regard to the numerical simulation of the effect of pumping water from big radiation well of groundwater reservoir of Tailan River, a sophisticated numerical simulation technology of radiation well using  the radiation well substructure method and substructure switch device was proposed based on the seepage analysis of big radiation well, and a finite element analysis of unsteady seepage field of groundwater with the influence of radiation well using the improved cut off negative pressure method, incremental iteration method and the preconditioned conjugate gradients method of solving large sparse matrix was worked out. Using the 3-D visualization finite element seepage software platform GWSS, the numerical simulation of the tests of pumping water from radiation well of groundwater reservoir of Tailan River was carried out using this software platform. The study results show that for all observation wells the average absolute error of the calculation water level was 0.22 m, the maximum average absolute error of a single well water level was 0.40 m and a minimum value was 0.02 m, the calculation results and observation results of every observation well fitted well, therefore, the reliability of the program was verified. The radiation well substructure method can accurately simulate the seepage behavior and local seepage field of radiation well and it can be used for analysis of unsteady seepage field during pumping process of the radiation wells and to evaluate the effect of radiation well drainage.