天母地區受壓水層水理之研析

The Study of Confined Aquifer Hydraulic in Tianmu Area

林正浚(Cheng-Chun Lin)

指導教授 ： 倪至寬

國立臺北科技大學/工程學院/土木與防災研究所/碩士(2008年)

https://doi.org/10.6841/NTUT.2008.00226

摘要

一般具有深開挖之營繕工程，於工程建造初期，必定會對基地地質特性詳加調查，了解地質之組成狀況，評估深開挖時可能遭遇之風險性，並藉此慎選合適的工法及施工機具，以期在進度如期、成本如度、安全無虞的狀況下順利完成此工程。天母地區位於台北盆地的北側，係由軟弱的黏土層及安山岩塊層所組成，而安山岩塊層為一受限含水層，因此在此地區施作的深開挖營繕工程，必須詳加檢討開挖後其黏土層的重量是否足以克服受壓水層上舉的水壓，以防止開挖面隆起，造成上舉破壞。本研究係針對位於天母地區的建築基地，藉由現場抽水試驗的方法，配合水井學理論，求出正確的水理參數，規劃基地抽水井數量及位置，推估其影響範圍及沉陷量，於基礎深開挖的過程中，抽降安山岩塊層的受壓水層水位，以期達到安全施工的目的，並作為天母地區日後採抽水降壓施作基礎開挖時之參考。

關鍵字

軟弱黏土層 ； 安山岩塊層 ； 抽水試驗 ； 水理參數 ； 上舉破壞 ； 沉陷

並列摘要

For a construction project that involves deep excavation, it is generally a common practice to conduct an thorough in-situ geologic investigation of its underground soil at the initial stage, as to get a picture of the composition of the soil, and to evaluate the risk that might be encountered during excavation period, and to come up with the right choices of construction methods, equipments and machines as well, so as to finish the project as scheduled, within budget, and without safety problems.
The Tianmu area is located at the north side of Taipei basin. The soils under Tianmu area are mainly weakly clay layer and Ansan rock layer. The Ansan rock layer is itself a confined aquifer. Therefore, It must be evaluated whether the weight of clay above Ansan rock layer will overcome the uplifting water pressure in the confined aquifer while work of deep excavation is underway in this area, so as to avoid construction failure caused by heaving and uplifting.
This research is focusing on getting the correct hydraulic parameters and planning the quantity and position of pumping wells through pumping test in site and the well theory for the construction project executed in Tianmu area. Hopefully, the possible influence range and settlement due to dewatering of Ansan rock layer can be obtained, and the safety of construction can be improved. The results of this research could also be used as references for construction projects with deep excavation and by dewatering method in Tianmu area.

並列關鍵字

Weakly clay layer ； Ansan rock layer ； pumping test ； hydraulic parameter ； heaving damage ； settlement

參考文獻

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[12] 亞新工程顧問股份有限公司，「國泰天母購物中心抽水試驗服務工作報告」(1999)。

[2] Theis, C. V. (1935),The relation between the lowering of the piezometric surface and the rate and discharge of a well using ground water storage, Transactions of the American Geophysical Union 16th Annual Meeting.

[3] Jacob, C.E. (1940), On the flow of water in an elastic artesian aquifer, Transaction, American Geophysical Union.