降雨引至地下水位變化及坡地變位之案例探討

A case study on groundwater variation and slop displacement induced by rainfall

鄭清江(Ching-Jiang Jheng) ； 楊嘉瑜(Chi-Yu Yang)

《華梵藝術與設計學報》 10期 (2015/07) Pp. 141-155

摘要

本研究以華梵大學校區之坡地作為主要研究區域，為了永續發展，設置多種監測儀器，依據傾斜觀測管歷年位移滑動資料，結合颱風警報期間之雨量資料，整理出對於未來研判坡地潛在滑動安全警戒值。而本文著重探討地下水位與坡地變位間之關係，首先根據自動水位量測資料，整理出地下水位與雨量之間的關係，其次利用地下水檢層之試驗來測定地下水含水層之特性或水脈位置，其結果顯示若能減少地下水位高度則能減少變位量的產生，為此本校於今年設置兩口集水井，期望能減緩地下水位造成之坡地變位，在整治的過程中亦使用SAA 即時量測位移量，以監測在集水井施作中所產生之位移量，以作為坡地防災與維護管理之參考依據，進而減少與防止坡地之災害發生。

關鍵字

降雨 ； 水位變化 ； 警戒值 ； 坡地變位 ； 集水井

並列摘要

Considering variations in the groundwater level owing to rainfall, and analyzing and comparing displacement and subsidence amount with various monitoring data recorded by observation stations on the ground surface are significant. According to the displacement and slide data measured in the inclinometers over the years, safety warning values for the potential of slope sliding are defined, by combining rainfall data recorded by weather stations during typhoon alerting. The warning values are then to be references of management for slope safety influenced by typhoon storms within Huafan University in the future. This study focuses on the relationship between the groundwater level and slope displacement. First, relationship between groundwater level and rainfall is concluded, such as delay effect and changes in depth of groundwater level, based on the data of automatic measuring of groundwater level. Second, aquifer features or positions of groundwater channels and maximum groundwater level within the monitoring area are detected by groundwater logging. The results show that the displacement amount decreases when the groundwater level lowers. Accordingly, two water collecting wells were set at the campus to minimize the slope displacement resulting from ground water rising and to boost the slop stability. During the remediation the displacement is measured by real time SAA to monitor displacement when the water collecting wells were mounting. Finally, the results and progresses of the remediation applying tapping wells are introduced to be references of disaster prevention and management of slope, and to minimize and prevent occurrence of slope disasters.

並列關鍵字

Rainfall ； Water level changes ； Warning value ； Slope displacement ； Water collecting well