The seepage characteristics of a single well dewatering from an unconfined aquifer bottom

Authors

LI Yang, Henan Province Bureau of Hydrology and Water Resources, Zhengzhou 450003, China
WANG Wenxue, Henan Province Key Laboratory of Rock and Soil Mechanics and Structural Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450045, ChinaFollow
XIAO Hang, Henan Province Bureau of Hydrology and Water Resources, Zhengzhou 450003, China
SUN Yi, Henan Province Geology and Mining Construction Engineering LTD, Zhengzhou 450007, China
WANG Yun, Henan Province Geology and Mining Construction Engineering LTD, Zhengzhou 450007, China
DI Mengna, Henan Province Geology and Mining Construction Engineering LTD, Zhengzhou 450007, China

Abstract

Dewatering from an aquifer bottom for drain and depressurization is one common method to ensure safety mining. This method is significantly different from pumping from the ground. In order to study the seepage characteristics of the dewatering hole(well), the seepage characteristics of a single well dewatering from an unconfined aquifer bottom was taken as an example and studied using numerical simulation method. The results show that when l_w<l_c, the pore water pressure above the dewatering well is greater than zero, which presents the rule of increasing first then decreasing from bottom to top, and the seepage flow increases with well length following an exponential function relationship. When l_w ≥ l_c, the seepage characteristics and seepage flow of the incomplete dewatering well is the same with the complete dewatering well. The seepage flow increases with the well radius following a power relationship with the exponent less than 1. By substituting s+l_w into Dupuit formula for unconfined complete wells instead of drawdown s, a revised formula was proposed which could be used to cal_culate water flow for uncomplete dewatering wells with a more accurate result. This study will provide an important theoretical basis for understanding the seepage characteristics and more effectively drilling of the dewatering wells.

Keywords

aquifer, dewatering well, seepage flow, Dupuit formula

DOI

10.3969/j.issn.1001-1986.2019.03.024

Recommended Citation

LI Yang, WANG Wenxue, XIAO Hang, et al. (2019) "The seepage characteristics of a single well dewatering from an unconfined aquifer bottom," Coal Geology & Exploration: Vol. 47: Iss. 3, Article 25.
DOI: 10.3969/j.issn.1001-1986.2019.03.024
Available at: https://cge.researchcommons.org/journal/vol47/iss3/25

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