寬口井降水對地下空間結構的長期穩定性控制研究-以清洲淨水場為例

The research in the long-term stability control of the precipitation of the wide well to the structure of the underground space -According to Kiyosu water treatment

王群賀(Chun-Ho Wang)

指導教授 ： 張達德

中原大學/工學院/土木工程研究所/碩士(2012年)

https://doi.org/10.6840/cycu201200607

摘要

臨海岸地區的地下水位受到海水潮汐漲落的影響而產生上下起伏，於執行抽水試驗時，此周期性的變動對地下水位洩降是否有明顯的影響，在不具有局限水層的卵礫石地層是否更為明顯，仍值得進一步探討。
本研究藉由工程案例「清洲淨水廠新建工程」執行現場抽水試驗進一步瞭解，此類地層的水理特性，包含導水係數T、儲水係數S，滲透係數K等，參考Moench（1997）推求洩降錐型曲線及影響半徑，並用數值程式SEEP/W 建立群井洩降模型，依據單井抽水試驗的數據推估群井洩降的機制，藉此規劃地下結構洩壓井抽降水系統，以達到結構物長期穩定的控制需求。
研究規劃利用程式模擬三種抽水量分別為18CMH、36CMH、72CMH，並考慮地下水位暫時狀態及穩定狀態的水位高程，同時考量工程新建階段與完工營運階段不同的結構穩定條件，為數值模型建立的依據。分析結果為，小抽水量（18CMH）的模型無論是開挖階段或營運階段均無法滿足穩定需求，抽水量（36CMH）的模型在開挖施工階段能滿足安全需求，但是於營運階段時卻無法達到穩定的需求，抽水量（72CMH）的模型在開挖施工階段於地下水位穩定狀態時降水深度大於預定深度，而在營運階段則此抽水量則滿足穩定需求。

關鍵字

數值SEEP/W 群井洩降模型 ； 導水係數T ； 卵礫石地層 ； 現場抽水試驗 ； 儲水係數S ； 滲透係數K

並列摘要

The fluctuations of the groundwater level in the coastal area directly affected by the ocean tide. In study of pumping test, whether the periodically variation of ocean tide has a significant effect on groundwater drawdown and more significant effect in the condition of gravel formation without confined aquifer is worthy of further investigation.
For hydrodynamics evaluation of gravel formation without confined aquifer, a pumping test in the new project of Kiyosu water treatment was studied to estimate the aquifer parameters transmissivity, coefficient of storativity, and hydraulic conductivity. Calculate the cone of depression and radius following Moench (1997), and construct the drawdown behavior model of group of wells through numerical simulation by available software SEEP/W. The hydraulic coefficient obtained from pumping test to adjust the design of relief wells in order to maintain the structure stabilization in the long run.
The paper used three level of pumping volume settings 18CMH, 36CMH, and 72CMH in numerical analysis. Several conditions such as groundwater level in transient state and equilibrium, structure stabilization in construction phase and operation phase are considered to construct the drawdown model. No matter in construction phase or operation, we find that groundwater level does not meet the safety requirement in lower pumping level (18CMH). In medium pumping volume (36CMH), the groundwater level does meet the safety requirement in construction phase but does not meet the stable requirement in operation. In the model of higher pumping volume (72CMH), given that groundwater level achieves the equilibrium, results shows that groundwater drawdown exceed the expectation in construction phase, but meet the stable requirement in operation.

並列關鍵字

Hydraulic conductivity（K） ； Pumping test ； SEEP/W Model ； coefficient of storativity（S） ； Transmissivity（T） ； Gravel formation

參考文獻

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