以電氣探測法分析向陽森林遊樂區遊客中心地下含水情形

Analysis of Groundwater Content in Tourist Center of Xiangyang Forest Recreation Area by Ground Resistance Detection

許中立(Chung-Li Hsu) ； 黃靚文(Ching-Wen Huang) ； 江佳燕(Jia-Yan Jiang) ； 陳淑慈(Shu-Tzu Chen)

《中華水土保持學報》 51卷3期 (2020/09) Pp. 95-108

https://doi.org/10.29417/JCSWC.202009_51(3).0002

摘要

向陽森林遊樂區周邊本就存在大規模崩塌潛勢，於2009年因莫拉克颱風更造成遊樂設施區及營林區損害嚴重，其中遊客中心地層地下水位長年偏高，為防止地下水影響邊坡之穩定性，本文利用地球物理探測的電氣探測法，對此區地層特性進行調查分析。共在研究區域內設置5條測線、29個測點，每個測點深度可達9-33 m，利用探測所得之資料繪製成ρa-a曲線圖分析其特性，再將探測所得數據繪製成二維地層電性剖面圖，並將研究結果與傾度管資料及鑽探資料進行比對確認。本文分析結果顯示遊客中心下主要地層結構為棕灰色砂岩及板岩所集結的崩積層及破碎板岩帶為主，其結構為較不良之破碎板岩夾石英為區域內高含水層主要分佈區域，藉由與地中位移量比對發現遊客中心地層之位移型態幾乎以地層擠壓為主，變化區間主要發生高含水地區，故建議應利用橫向集水管工程來排除不利於地層穩定之淺層及較深處之地下水，以增加該區邊坡之穩定性。

關鍵字

電氣探測法 ； 大規模崩塌 ； 地下水 ； 邊坡穩定

並列摘要

Xiangyang Forest Recreation Area is a large-scale landslide potential area which groundwater of the tourist center was high for a long time. In order to prevent the groundwater from affecting the slope stability, this paper uses the earth electrical logging method to investigate and analyze the stratum characteristics. A total of 5 lines and 29 measuring points are set. The depth of each measuring point can reach 9-33m. The data obtained by the detection is used to analyze the characteristics of ρa-a curve, plotted as 2D electrical stratum profile, and compared with the dip tube and drilling data. The results show that the main stratum structure is mainly composed of brown-gray sandstone and slate aggregated fractured layer and fractured slate belt. The structure is characterized by poor fractured slate and quartz as the main distribution area of high aquifer in the area. By comparing with the displacement in the ground, the displacement pattern of the tourist center stratum is almost dominated by stratigraphic compression, and the variation interval mainly occurs in high water-bearing areas. Therefore, it is recommended that the horizontal water collection pipe project should be used to eliminate the groundwater, so as to increase the slope stability.

並列關鍵字

earth electrical logging method ； large-scale landslide ； groundwater ； slope stability