以不同試驗求取臺中都會區卵礫石層透水係數之探討

THE COEFFICIENTS OF PERMEABILITY OF GRAVELLY BOULDER DEPOSIT IN TAICHUNG METROPOLITAN AREA BY DIFFERENT EXPERIMENTS

鄧源昌(Yuan- Chang Deng) ； 黃俊鴻(Jin- Hung Hwang) ； 高世鍊(Shi-Lien Gao) ； 周坤賢(Kun-Hsien Chou) ； 林廷芳(Ting-Fung Lin)

《中國土木水利工程學刊》 35卷7期 (2023/11) Pp. 681-694

https://doi.org/10.6652/JoCICHE.202311_35(7).0006

摘要

抽水井設計為臺中都會區卵礫石層深開挖工程的重要課題，而卵礫石層的透水係數為設計之關鍵參數。本研究於某一大型深開挖工程基地，規劃試坑開挖、鑽探取樣、現地抽水試驗、鑽孔內透水試驗與卵礫石基質透水試驗，探討不同試驗方法所求參數之差異，並探討其在抽水系統設計之適用性。研究結果顯示定流量與變流量抽水試驗所得透水係數K_r相近，其範圍約為2.0 × 10^(-2) ～ 3.6 ×10^(-2)（cm/s），以此設計之抽水控制方案，於後續施工已證實其合理性。主抽水井單井分析之參數與多井分析結果差異不大。鑽孔內透水試驗之參數遠較抽水試驗為小，不適用於抽水井設計。基質透水試驗之參數較抽水試驗小，但差異小於一個量級，經過經驗修正後，可應用於小規模深開挖工程。最後總結各種透水試驗應用在卵礫石地層之優缺點與適用性，供工程界參考應用。

關鍵字

卵礫石層 ； 基質 ； 透水係數 ； 抽水試驗

並列摘要

The design of the pumping well is an important subject of the deep excavation project constructed in the gravelly boulder deposit in Taichung metropolitan area, and the permeability coefficient of the deposit is the key parameter of the design. This study planned pit excavation, drilling and sampling, in-situ pumping test, borehole slug test and laboratory permeability test on the matrix of gravelly boulder deposit in a large-scale deep excavation site to explore the discrepancies of the coefficient of permeability derived by different test methods, and to explore their applicability in pumping system design. The research results show that the coefficients of permeability K_r obtained from the constant flow and variable flow pumping tests are similar, and their range is about 2.0 × 10^(-2) ~ 3.6 × 10^(-2) (cm/s). The pumping control scheme designed in this coefficient has been confirmed as rationale in the subsequent construction. The parameters from the single-well analysis of the main pumping well are close to the results of the multi-well analysis. The parameters of the borehole slug test are much smaller than those of the pumping tests, and are not suitable for the design of pumping wells. The parameters of the matrix permeability test are smaller than those of the pumping tests, but the difference is less than one order of magnitude. After modification by experience, it can be applied to small-scale deep excavation projects. Finally, the advantages, disadvantages and applicability of various permeability tests in the gravelly boulder deposit are summarized for reference and application in the engineering community.

並列關鍵字

gravelly boulder ； matrix ； coefficient of permeability ； pumping test ； slug test

參考文獻

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