指導教授:賈儀平臺灣大學:地質科學研究所詹宛真Chan, Wan-ChenWan-ChenChan2014-11-262018-06-282014-11-262018-06-282014http://ntur.lib.ntu.edu.tw//handle/246246/262012裂隙岩層中地下水流及汙染傳輸主要受控於少數的透水性較佳的裂隙,然而裂隙水流分布複雜,調查極為不易。岩芯分析與傳統井測不易判釋透水裂隙,而水力試驗難以估算裂隙的水文地質參數,常用的示蹤劑試驗在裂隙岩層中經常失靈,因此本研究嘗試整合運用複井水力試驗、熱脈衝流速儀量測及示蹤劑試驗,在研究井場進行現地試驗,探討偵測裂隙岩層中優勢水流路徑的方法,期能對岩層地下水資源調查與地下水污染傳輸過程等議題,建立有效的調查方式。 本研究之試驗井場位於南投縣信義鄉台大實驗林和社營林區內,鑽取的岩芯主要是輕度變質的頁岩或粉砂岩,岩層多處呈現破裂,地表裂隙調查指出井場附近的砂岩層至少存在三組裂隙。本研究首先進行熱脈衝流速試驗,偵測各個井孔中透水性較佳的岩層裂隙所在位置,試驗結果指出岩層中裂隙的透水性與裂隙密度大小並無絕對關係。然後進行複井抽水試驗,確認井孔之間的水力連通程度,再依據水力試驗所得之初步調查結果,選取水力連通性較佳的兩個井孔進行示蹤劑試驗。繼而改良過去的示蹤劑試驗方法及材料,分別使用奈米鐵及氯化鈉水溶液,運用灌注方式製造強制流場,調查井孔之間岩層裂隙水力連通性。研究結果發現,氯化鈉示蹤劑可以證實兩個井孔的水力連通性,然而氯化鈉的高擴散性難以定位透水裂隙所在;具磁性的奈米鐵示蹤劑,則可成功偵測出監測井與投注井水力連通裂隙的位置,因此奈米鐵示蹤劑試驗材料與方法有潛力發展成為未來調查岩層優勢地下水流路徑工具之一。Groundwater flow in the fractured rock is mainly controlled by a few permeable fracture. Core analysis and acoustic televiewer can be used to examine the fracture density and orientation, but difficult to characterize whether rock fractures are permeable. In this study, we integrate a variety of field tests, including tracer test, hydraulic test, and heat-pulse flowmeter test, to locate the permeable fractures and to detect the hydraulic connections between boreholes. The field study was conducted at Heshe hydrogeological experimental well station in central Taiwan. There are eight test wells and two observation wells at the site where the in-situ rock below the overburden is primarily shale and siltstone. Surface geological survey shows three sets of joint planes. In order to detect the preferential pathway of groundwater flow, heat-pulse flowmeter measurement was adopted to identify the depth of permeable fractures in the boreholes. It was followed by the multi-well pumping test for investigating the hydraulic connectivity between these wells. The tracer tests were then used to detect the hydraulic connectivity of permeable fractures between two wells. By injecting saltwater or nano zero-valent iron into one well, it is possible to detect the variation of tracer in the nearby wells. We found nano zero-valent iron adsorbed by a magnet array in the detection well in two tracer tests. The adsorbed nano iron can specifically locate the position of permeable fractures connecting to the injection well. Our study results show that the nano iron tracer test is a potential useful tool to investigate the preferential groundwater flow in the fractured rock.口試委員會審定書 # 致謝 i 摘要 ii 目錄 iv 第一章 前言 1 1.1 研究動機及目的 1 1.2 文獻回顧. ..1 第二章 示蹤劑 3 2.1 奈米鐵示蹤劑 3 2.1.1 奈米鐵示蹤劑的製備 3 2.1.2 奈米鐵示蹤劑物理及化學性質 6 2.1.3 奈米鐵示蹤劑試驗設計方法 7 2.2 氯化鈉示蹤劑 9 2.2.1 氯化鈉示蹤劑的製備 9 2.2.2 氯化鈉示蹤劑物理及化學性質 9 2.2.3 氯化鈉示蹤劑試驗設計方法 9 第三章 和社水文地質試驗井場 10 3.1 地質背景.. 10 3.2 複井抽水試驗 15 3.2.1 四號井複井抽水試驗結果 16 3.2.2 三號井複井抽水試驗結果 18 3.3 前期地質調查資料分析 20 3.3.1 三號井 21 3.3.2 四號井 22 3.3.3 六號井 23 3.3.4 七號井 24 3.3.5 八號井 25 第四章 和社井場示蹤劑試驗 27 4.1 B井群示蹤劑試驗 27 4.1.1 示蹤劑試驗規劃 27 4.1.2 奈米鐵示蹤劑試驗結果 30 4.1.2.1 水位變化 30 4.1.2.2 電導率變化 31 4.1.2.3磁鐵陣列吸附量 33 4.2 A井群示蹤劑試驗設計與結果 34 4.2.1 示蹤劑試驗規劃 34 4.2.2 氯化鈉示蹤劑試驗 36 4.2.2.1 水位變化 36 4.2.2.2 電導率變化 37 4.2.3 奈米鐵示蹤劑試驗 39 4.2.3.1 水位變化 39 4.2.3.2 電導率變化 40 4.2.3.3 磁鐵陣列吸附量 42 4.3 示蹤劑試驗結果分析與解釋 43 4.3.1 B井群示蹤劑試驗分析 43 4.3.2 A井群示蹤劑試驗分析 45 4.3.3 氯化鈉與奈米鐵示蹤劑試驗比較 47 第五章 討論 50 5.1 反向示蹤劑試驗結果 50 5.2 示蹤劑阻塞裂隙及沉降效應 53 5.2.1 三號井複井抽水試驗 53 5.2.2 室內奈米鐵示蹤劑試驗 55 第六章 結論與建議 58 參考文獻 602404101 bytesapplication/pdf論文公開時間:2019/09/03論文使用權限:同意有償授權(權利金給回饋本人)裂隙岩層地下水示蹤劑試驗奈米鐵應用示蹤劑試驗調查裂隙岩層中優勢地下水流路徑Tracer Tests in the Fractured Rock for Investigating Groundwater Flow Pathwaythesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/262012/1/ntu-103-R00224212-1.pdf