強降雨會升高山坡地地下水位及產生地下水滲流，導致土壤流失及邊坡滑動。本研究驗證洪耀明(2019)所建立之建立深層崩塌臨界地下水位及臨界滲流沖蝕長度理論及計算模式。首先選擇梨山地滑地，透過室內試驗，包括夯實試驗、達西定律之K值試驗、壓密排水三軸試驗，獲取理論所需參數，再帶入邊坡破壞理論公式，計算發生崩塌之臨界地下水位及臨界滲流沖蝕長度，並與水土保持局之分析成果比較，發現臨界地下水位預測與實際發生位置相符，滲流沖蝕位置較水土保持局模式估算位置短，可進一步至現場確認。 Heavy rainfall will increase the groundwater level and induce groundwater seepage erosion to result in soil loss and landside. This study validates the theory and calculation model established by Hong(2019) to establish the critical groundwater level and critical seepage erosion length of deep-seated landslide. First, Lishan landslide was selected. Through laboratory experiment, including the compaction test, the K value test of Darcy's law, and the triaxial test of compacted drainage, the parameters required by the theory are obtained, and then brought into the theoretical formula of slope failure to calculate the criticality of deep-seated landslide. Groundwater level and critical seepage erosion length are compared with the analysis results of the Bureau of Soil and Water Conservation. Prediction of the critical groundwater level is consistent with the actual location. The seepage erosion position is shorter than the estimated position of the model of the Soil and Water Conservation Bureau, which can be further confirmed on site.
