本研究對一組規則節理岩坡之傾倒破壞進行探討，利用二維數值分析軟體UDEC進行模擬分析。本研究依岩坡內張力破壞漸進式發展循序定出六個歷程，針對最大及最小主應力分佈及坡面上不同位置之水平及垂直位移，進行分析比較。
此外傾倒破壞含有不連續面存在，考量節理勁度比是一個影響節理行為的重要參數，故本研究選定三種不同節理勁度比kn/ks (5/1、10/1、20/1)，配合三種陡峭節理傾角 (60°、70°、80°)來探討傾倒破壞之工程行為。研究結果顯示這些組合情況下之通過坡趾張力破壞發展均朝垂直於節理之方向延伸，而最陡之80°傾角，張力裂縫會先在坡面與通過坡頂之節理面範圍內之張力裂縫帶會上下變厚後才持續向後延伸。

This study focuses on the toppling failure in the regular joint using the two-dimensional simulation program, UDEC. Six steps of phase were selected based on the tensile failure development of rock slope. The comparisons of the distribution of maximum and minimum stress as well as the displacement in vertical and horizontal direction were mainly discussed.
Since the discontinuities cause toppling failure, considering the joint stiffness is one of the most important parameters to affect the joint behavior, therefore, this study selected three different joint stiffness ratio (kn/ks=5/1, 10/1 and 20/1) with three steep dipping dip angles of joint (60°,70° and 80°) to analyze discuss the engineering behavior of toppling failure. The analytical results show that in these select conditions, tensile failures developed through the slope toe tend to extend toward the perpendicular direction of joints. Especially for the steepest dipping of joint (α=80°), the development of tensile crack first occurs in the range of the slope surface and the joints of slope crest, then the tension fracture zones start to extend again after it becomes thicker.

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