邊坡崩塌災害發生時不論於緊急搶修或長期整治,均須調查滑動面深度,若在未確切掌握之滑動面深度情形下,即進行緊急搶修或整治工程,往往由於地錨長度或排樁深度不足,而再次造成邊坡滑動,故掌握滑動面深度對崩塌地整治成功與否有著決定性的影響。 一般滑動面深度之判釋方法,大致可分為(1)由滑動規模之推估方法(2)岩心檢視之經驗方法(3)監測之定量分析方法三種,本研究係對於滑動面判釋方法加以綜合整理,以一代表性案例,運用滑動規模、岩心檢視及監測等方法研判滑動面深度,其中針對實務界常用於邊坡滑動面監測之傾斜觀測管,以觀測累積位移量相互關係,對其監測之滑動面深度有較準確之判釋;並以STABL及SLOPE/W邊坡穩定分析軟體,進行滑動面深度判釋,以試驗結果及反推分析方法求得參數,經分析後研判滑動面位置,期藉以瞭解邊坡穩定分析方法在監測資料不足時,如何設法研判邊坡滑動面之可行性。
When a slope slide occurs, the depth of rupture of surface must be investigated no matter for the purpose of emergency rescue or long-term control. If the emergency rescue or control construction is executed without knowing the exact information of the depth of rupture surface, the slope slide is likely to occur again due to insufficient length of ground anchors or soldier piles. Therefore, there is decisive influence in knowing the information regarding the depth of rupture surface to the success of control construction. In general, there are 3 ways to identify the depth of the rupture surface, and they are (1) estimation from the scale of the slide; (2) empirical method by examining the rock core samples; and (3) quantitative analysis by monitoring. In this study, the method of identifying the surface of rupture will be summarized and the depth of the surface of rupture in a representative case will be examined using scale of slide, rock core sample examination and monitoring. In those 3 methods, the inclinometers that are commonly used in the practice of monitoring the rupture surface in a slope to observe the relativity of the accumulated displacement is more accurate in examining the monitored depth of rupture surface. Also, the slope stability analysis software, STABL and SLOPE/W, is used to obtain the necessary parameters using the result of experiments and back analysis. The location of the surface of rupture is identified after series of analysis to understand the feasibility to identify the surface of rupture in a slope using the slope stability analysis method when there is insufficient data.