賈儀平2006-07-252018-06-282006-07-252018-06-282000http://ntur.lib.ntu.edu.tw//handle/246246/11746穿越山區岩層的隧道施工往往會遭遇 湧水及地下水枯竭的問題。興建中的坪林 隧道頭城段即在四稜砂岩中屢遭湧水困 擾；因此亟需對該區之水文地質及地下水 系統有所瞭解。本計畫研究結果顯示四稜 砂岩具中低度的儲水能力，但岩層破裂面 則具良好的導水能力，所以開挖至破碎帶 時，初期的湧水量可能很大，由於四稜砂 岩中破碎帶的連通性頗佳，可匯集廣大地 區之地下水，且隧道低於地下水面約兩百 至五百公尺，湧水維持甚久。 本區調查研究結果所建立之水文地質 架構，以數值模擬方法分別探討隧道施工 前後的變化情況。施工前自然地下水流模 擬結果可初步提供研究地區的水流方向及 隧道沿線之水壓分佈情況；而開挖後的模 擬結果顯示，隧道沿線附近地區地下水流 有向導坑集中的現象，且開挖面附近的地 下水位變化較大，並可應用於初步評估施 工對附近地區水資源的影響。 本研究嘗試研發利用流速儀量測井孔 中垂直方向上地層之透水性，在實驗室完 成校正後，並於兩口觀測井進行現地試 驗。配合定量抽水，流速儀可量測每公尺 範圍之流量變化，再藉由單井水位回升試 驗量測之導水係數，可分別估算不同深度 地層之水力傳導係數，預期此項技術將有 助於隧道湧水潛勢之調查。The construction of Pinglin tunnel has often encountered large quantities of ground water. Dewatering in the tunnel could reduce the ground water level in the Sezleng Sandstone and spring flow in the nearby area. Hence, it is essential to understand hydrogeologic conditions and ground water flow in the area. The study results provided a preliminary hydrogeologic framework. Modeling of natural ground water flow and ground water seepage around the tunnel would provide hydrogeologic information for evaluating ground water flow and water pressure before the tunnel construction and the impact of construction on local water use. Moreover, the research adopted a heat pulse flowmeter and an impeller flowmeter to conduct continuous measurement of the variation of flow rate in two boreholes. Combining the measured flow rates and the overall hydraulic conductivity calculated from the recovery test, the detailed distribution of formation hydraulic conductivity in the vertical direction can be delineated. It is anticipated that further research would enhance the resolution of investigating the potential ground water seepage problems due to tunnel construction in the future.application/pdf24309 bytesapplication/pdfzh-TW國立臺灣大學地質科學系暨研究所四稜砂岩地下水水文地質流速儀Sezleng SandstoneGround WaterHydrogeologyFlowmeterreporthttp://ntur.lib.ntu.edu.tw/bitstream/246246/11746/1/892116M002012.pdf