摘要 本研究以物理試驗與數值模型探討逆向楔形岩坡破壞機制受弱面性質之影響,並由相關的破壞機制討論其對應之有效整治策略。由於現地楔形塊體常由多組弱面切割而失穩,因此楔形岩坡之穩定性及塊體破壞機制可能受到弱面性質影響,進而影響其有效之整治方式。 本研究以離心試驗及數值模型探討楔形岩坡受弱面性質之塊體位移特性,並分析影響整體穩定性之關鍵塊體。離心試驗結果指出,岩楔運動機制與坡體尺寸的相關性較低,但坡體尺寸愈大,其受影響範圍愈大,且崩落比亦較高;此外在高重力場下,塊體濕度較高所產生之凝聚力也會使試驗模型之崩落率較低。由經過驗證後的逆向楔形岩坡的數值模型可以得知,失穩的岩楔大多會先由坡趾及坡面產生翻倒或滑動破壞;若楔形岩坡節理間距縮小為原本模型之一半,岩楔因被切得更細小導致崩落率增加;且隨著兩弱面角之面角與交線傾伏角提升,則崩落率也隨之增加。 本研究以驗證後的數值模型,探討具有不同地質參數與塊體間凝聚力楔形岩坡之崩落關鍵塊體,並在固定(整治)關鍵塊體後,分析模型在不同尺度下之變形及整治策略之有效性;此外,本研究亦分析楔形塊體崩落後殘坡塊體接觸面之穩定性,其結果亦與實驗及數值分析相符;最後,本研究以台2線83K一處倒懸岩坡進行現況極端條件下的模擬,觀察塊體崩落與堆積狀況,並嘗試分析現況邊坡之關鍵塊體,以對於其整治策略進行建議。 關鍵詞:楔形破壞、離心機試驗、3DEC、關鍵塊體、整治策略 ;Abstract In this study, the failure mechanism and the mitigation measures of the wedged rock slopes that were separated by several weak plane sets were analyzed using physical tests and numerical models. The wedged rock slopes are commonly separated by more than two weak planes based on field investigation results. The stability, failure mechanisms, and movement of the rock wedges of the wedged rock slopes may also be affected by the orientation of the beddings and weak planes. This study uses centrifuge tests and numerical models to explore the stability of the wedged rock slopes with different configurations of weak plane characteristics. The above physical and numerical analysis investigated the key wedge block to initiate the subsequent movements of the remaining wedges. The centrifuge test results indicate that increasing the slope scale can result in the rise of the collapsing rate of the rock wedges. The environmental humidity could increase cohesion between the wedges, hence enhancing the stability of the wedged slope. Based on the validated numerical models, the toe and superficial blocks of the wedge rock slopes were the first ones to fall off. Moreover, the smaller the spacing of the wedged slope, the larger the overall collapsing rate. With the validated numerical models, the author attempted to stabilize the key blocks that could initiate the subsequent wedge movements. Results have shown that the overall collapsing rate has decreased significantly, and the improvement is highly related to the plunge of the intersection. Finally, an actual wedged slope that is separated by three joint sets was analyzed numerically under zero joint plane strength conditions, hoping to explore the possible run-out and accumulation behaviors of the wedged blocks. Key words:wedge failure、centrifuge test、3DEC、key block、mitigation strategies