Seepage Characteristics of a Single Ascending Relief Well Dewatering an Overlying Aquifer

Water

Boris Faybishenko¹  Jinyu Dong²  Tong Jiang²  Wenxue Wang²  Yang Li³ 

[1] Energy Geosciences Division, Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720, USA;Henan Province Key Laboratory of Rock and Soil Mechanics and Structural Engineering, North China University of Water Resources and Electric Power, 136 Jinshui East Rd, Zhengzhou 450045, China;Hydrology and Water Resources Bureau of Henan Province, Zhengzhou 450003, China;

关键词: ascending relief well;    groundwater;    seepage;    sand-tank;    modeling;    dupuit formula;    dupuit-thiem formula;   

DOI  :  10.3390/w12030919

来源: DOAJ

【 摘 要 】

The application of groundwater relief, i.e., dewatering, ascending wells, drilled upward from the mining tunnel into the overlying aquifer, is common in underground mining engineering. In this study, the seepage characteristics of single ascending partially and fully penetrating relief wells are investigated using a series of laboratory sand-tank experiments and numerical simulations. The seepage characteristics of ascending wells dewatering an overlying aquifer are different from those of conventional pumping wells descending from the ground surface into the underlying aquifer, because of the pronounced influence of the seepage face boundary condition along the seepage boundary of the ascending dewatering well. The seepage face of the ascending well is formed as the well casing remains open and water is discharged under the action of gravity through the well casing. The results of laboratory sand-tank experiments and modeling show that when the degree of penetration of an ascending relief well does not exceed a critical value, the effect of the seepage face cannot be ignored. In particular, the seepage flux increases as the degree of penetration increases following an exponential function, and the relationship between the seepage flux and the well radius can be described using a power law function. The results of numerical simulations are used to develop a series of type curves to evaluate the effects of the critical degree of penetration for different well radii and different aquifer water levels. Modified versions of the Dupuit and Dupuit−Thiem formulae for a single ascending partially well for the degree of penetration less than the critical one for the unconfined, confined, and confined-unconfined aquifers are developed.

【 授权许可】

Unknown