2016 年 9 月 28 號，梅姬颱風挾帶的豪雨侵襲，引發一起位於高雄市燕巢山區的泥岩崩塌事件，損毀一棟民宅且活埋三人，也因此引起政府對於泥岩的關注，計畫將泥岩劃入崩塌潛勢區內，進行深入探究崩塌事件。
透過傳統邊坡分析法，如極限平衡法，較難以被分析崩塌原因與過程，本研究利用現地調查了解邊坡之工程地質條件，且進行土壤試驗分析材料特性，鏈結有限元素分析(FEA)和離散元素(DEA)個別探究破壞機制與動態移動過程。
於探討破壞機制中，本研究著重於觀察降水過程中孔隙水壓、飽和度及位移之變化，且透過位移之斜率瞬間變化，探討可能崩塌時間，其研究結果顯示靠近地表面之監測點由於最快受到雨水入滲影響，孔隙水壓和飽和度之反應較其他監測點快速，較快進入浸潤帶；根據位移之斜率瞬間變化，可能崩塌時間是在颱風降雨期間的第 28 小時。於分析動態移動過程中，初始滲流力得透過鏈結有限元素分析結果。依據摩擦力之變化，探討水入滲對動態移動過程之影響及重建崩塌之動態移動過程。分析結果指出水入滲與地形起伏對動態移動過程有著相當大之影響，在動態移動過程中，滑動最大速度為 4.41 m/s，之後主要受到地形坡度較緩之影響，可觀察出崩塌塊體呈現明顯之減速行為。總體而言，本研究表明透過結合有限元素分析和離散元素分析可以用來調查山崩的破壞機制並提供實用的見解。這個方法可以應用於分析其他地質災害且幫助我們對於破壞機制有著更深一層的了解。

On September 28, 2016, due to the typhoon Megi, mudstone slope failed in in Yanchao district, Kaohsiung city, which damaged a building and buried three lives. To investigate the mechanism of the rainfall-induced mudstone landsliding, the field investigation was used to evaluate the geological conditions of the study area and the experiments were conducted to obtain the characteristics of geomaterials. Then, finite element analysis (FEA) and discrete element analysis (DEA) were employed to explore the driving mechanism in the prefailure regime and the dynamic runout process in the postfailure regime, respectively.
In FEA, the driving mechanism was revealed in terms of the pore water pressures, saturations, and displacement of the sliding zone. The onset of the rainfall-induced landsliding was found by the rapid change of source displacement (RCSD). The result indicated that the variation of saturation and pore water pressure at the monitor points near the surface was earlier than other locations, because rainfall first passes through the monitoring points near the surface; The likely failure timing was ascertained as 28 hr from the beginning of the typhoon rainfall. In DEA, based on the result of the FEA, the estimated seepage force was obtained. To account for water infiltration associated with the dynamic runout process of the landsliding and reconstruct the dynamic runout process of the landsliding, the reduced sliding friction coefficient in DEA was examined. Based on the results, satisfactory agreement between the numerical analysis and landslide behavior was realized. Water infiltration and transition in steepness play significant roles in the behavior of the dynamic runout process. The landsliding exhibited a maximum speed of 4.41 m/s and decelerated as it reached a gentler slope. Overall, the study indicated that the combination of FEA and DEA can be utilized to investigate the failure mechanism of landslides and provide useful insights. The approach can be a high potential to investigate many other geotechnical problems and help us better understand their mechanism.

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