大規模崩塌區橫向集水管地下排水之水位洩降面推估

Estimation of Groundwater Drawdown Due to Subsurface Horizontal Drains for Large Landslides

林德貴(Der-Guey Lin) ； 黃郁博(Yu-Po Huang) ； 朱家勁(Eugene Choo)

《中華水土保持學報》 53卷3期 (2022/09) Pp. 146-166

https://doi.org/10.29417/JCSWC.202209_53(3).0002

摘要

本研究採用三維數值方法及經驗方法，針對坡地橫向集水管地下排水工程，進行定水頭補注情況下之穩態排水分析，並推算地下排水後之地下水水位洩降面。採用數值方法計算之水位洩降面高度與Crenshaw & Santi（2004）經驗方法求得者相當吻合。正規化補注率乃影響地下水水位面洩降型態之重要參數，其僅為集水管打設間距及上邊坡邊界定水頭高之函數。集水管設置於透水性較佳之地層或集水管打設間距較小時，其降低並維持水位處於安全深度位置之能力較高，排水強度也較大。

關鍵字

橫向集水管 ； 地下排水 ； 正規化補注率 ； 地下水水位洩降面

並列摘要

Using 3-D numerical analysis and empirical methods, this study performed a series of steady-state drainage analyses under a constant groundwater recharge rate to estimate the groundwater drawdown attributable to subsurface drainage of horizontal drains for large landslides. The levels of groundwater drawdown calculated through the numerical method and through the empirical method, as proposed by Crenshaw and Santi (2004), coincided. The normalized groundwater recharge rate is the most crucial parameter influencing the drawdown pattern of groundwater levels and is alternately related to the spacing of horizontal drains and the groundwater constant head boundary at the upper slope. The horizontal drains will promote drawdown and will maintain the groundwater level at a safe depth under a larger drainage intensity if they are configured with a smaller spacing and are installed in a permeable soil stratum.

並列關鍵字

Horizontal drain ； Subsurface drainage ； Normalized recharge rate ； Groundwater drawdown surface

參考文獻

朱家勁 (2018)，「利用三維數值分析技術探討大規模地滑區地下排水系統之排水運作行為」，碩士論文，國立中興大學水土保持學系。(Choo, E. (2018). Investigation on the Performance of Subsurface Drainage System for Large Landslide Using Three-Dimensional Numerical Analyses. Master Thesis, Department of Soil and Water Conservation, National Chung Hsing University. (in Chinese))

林德貴 (2018)，「邊坡穩定地下横向排水工法設計指引－理論與實務」，水土保持局南投分局。(Lin, D.G. (2018). “Design Guidelines of Subsurface Horizontal Drains Used for Slope Stabilization-Theory and Practice.” Soil and Water Conservation Bureau, Nan Tau Branch Office. (in Chinese))

林德貴、張國欽、朱家勁、蘇苗彬 (2018)，「大規模地滑區地下排水穩定工法之效益評估」，中華水土保持學報，49(4)，199-213。Lin, D.G., Chang, K.C., Choo, E., and Su, M.B. (2018). “Evaluating the Efficiency of Subsurface Drainage Systems during Large Landslides.” Journal of Chinese Soil and Water Conservation, 49(4), 199-213. (in Chinese))

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