CAJ | 학술논문

弱透水层以黏性土为主，其渗流通常表现出低速非达西特性。开采条件下，弱透水层中咸水下移问题是典型的渗流-固结-溶质运移耦合问题。本文以华北平原典型的“上咸下淡”含水层系统为研究对象，采用修正的多场耦合模型，研究了弱透水层中非达西渗流固结过程对咸水下移的影响。研究结果表明，非达西渗流不仅增加了黏性土层的固结时间，而且，在一定程度上，减缓了咸水下移速度。同时，非达西渗流条件下流速具有削峰拖尾特征，天然水力梯度越大，拖尾越不明显，而削峰始终存在。咸水下移前期，不考虑固结过程时其运移速度更快，而在中后期，情况相反。阻滞因子决定了弱透水层渗流固结过程对咸水下移的影响程度。
약투수층이점성토위주，기삼류통상표현출저속비체서특성。개채조건하，약투수층중함수하이문제시전형적삼류-고결-용질운이우합문제。본문이화북평원전형적“상함하담”함수층계통위연구대상，채용수정적다장우합모형，연구료약투수층중비체서삼류고결과정대함수하이적영향。연구결과표명，비체서삼류불부증가료점성토층적고결시간，이차，재일정정도상，감완료함수하이속도。동시，비체서삼류조건하류속구유삭봉타미특정，천연수력제도월대，타미월불명현，이삭봉시종존재。함수하이전기，불고필고결과정시기운이속도경쾌，이재중후기，정황상반。조체인자결정료약투수층삼류고결과정대함수하이적영향정도。
Seepages in aquitard composed mainly of clay usually show the features of low-velocity non-Dar-cy flow. The downward migration of saltwater in aquitard is a typical problem of coupling fluid flow,soil consolidation and solute transport. This paper takes the example of a typical aquifer-aquitard system whose upper layer has salt water and lower layer has fresh water in the North China Plain. A modified coupling model has been used to study the influence of non-Darcy flow on vertically downward migration of saltwa-ter. The results show that the non-Darcy flow not only increases the consolidation time,but also slows down saltwater migration. Moreover,the velocity distribution of non-Darcy flow has peak cutting and tailing effect. In early phase of saltwater migration,its velocity without considering consolidation is faster than that with considering consolidation. However,it is opposite in latter. The retardation factor shows prominent effects on how the Darcy and the non-Darcy flow in the aquitard influences the downward migration of saltwater.