地下水位变化的数值模拟新方法

A NEW NUMERICAL METHOD FOR MODELING GROUNDWATER LEVEL VARIATION

尽管地下水数值计算技术和计算方法发展很快,地下水数值模拟仍然存在着大量的理论问题和实际问题需要研究解决,仍有很多局限性,由此可知,地下水模拟过程中充满了各种各样的不确定因素。如何利用和改进现有技术,减少模型的不确定性,提高数值模拟过程的有效性和预测结果的可靠性,是该研究领域具有挑战性的问题之一。在传统地下水数值模拟的基础上,提出一种预测地下水位变化的新的方法。该方法可以在拥有较少现场资料的情况下,对地下水水位的变化直接进行的预测。本研究的创新点在于减少模拟过程及模型校正过程中对输入数据的需求,简化边界条件;同时引入反复迭代方法求解控制方程,减少计算误差。该研究成果应用到实践中去,可以大大提高对地下水位的预测能力,此项研究及其成果将对水资源管理产生重大影响,对岩土工程设计及施工提供指导。

Although there is a vast development of the calculation methods and techniques of groundwater numerical simulation,it has some limitations in theories and practicalities and needs to be further researched and resolved. Therefore,the groundwater modeling process is still permeated with all kinds of uncertain factors. It is one of the largest challenges in this research field to fully utilize and improve the technologies on hand to eliminate the modeling uncertainty,to promote the validity of the numerical simulation process and the reliability of the forecasted results. Based on the traditional groundwater numerical modeling,a new groundwater model to make direct predictions on the groundwater level changes caused by the local stress fluctuations is developed. The variation governing equations related to confined and unconfined aquifers have been developed. It is verified that the simulation process for confined aquifer is as the same as those of traditional numerical simulation process. Otherwise,it is only approximation for unconfined aquifer. The predicted error will be increased as long as the increase of the absolute value of net change. This study introduces an iteration scheme,which can improve the perturbation results. The proposed new modeling reduces the requirements of input data in the modeling processes,and it can also simplify the boundary conditions and,at the same time,introduce the iteration scheme in solving the governing equation. When putting the results into practical use,it will increase prediction accuracy. This research will bring potential contributions to the water resources management and provide guidance for design and construction of geotechnical engineering.