臺灣博碩士論文加值系統

鑑於目前節理面強度研究大多集中於尖峰強度或殘餘強度之探討，對介於
兩者間剪力強度漸進衰減行為的研究則較少。本研究以含一系列大小不等
之三角形鋸齒剖面來模擬不規則節理，利用力平衡概念並配合Mohr-
Coulomb強度準則，先求剖面上各組成鋸齒中基本剪力行為數學模式，再
依大小鋸齒間之剪動接觸機制，經疊加組合單一鋸齒對整體剪力行為之貢
獻，進而推導得節理面之完整剪力剪位移行為。並經節理面物理模型剪力
試驗結果與3DEC分析結果之初步驗證。研究結果得致下列幾點主要結論
：(1)透過本文建議方式將不規則節理面以三角形鋸齒規則化後，所形成
含不同大小多鋸齒剖面之剪力行為，經試驗驗證得知其可有效反應第一級
節瘤主控剪動行為之事實。(2)本文以各組成鋸齒上坡角大小作正向力之
分配原則，先計算各單一組成鋸齒之基本剪力剪位行為，再依序疊加剪動
過程中各鋸齒之基本剪力行為，而得到節理面完整的剪力位移曲線。經與
試驗結果比較後，證明數學模式的適用性頗高及其對正向力分配原則之可
信度。(3)本文數學模式能準確預測尖峰剪力強度及鋸齒剪斷位置。尤其
是對較低正向力下，因鋸齒漸進爬坡磨損行為較為明顯例子。(4)本文數
學模式可探討剪力勁度、尖峰剪力強度及剪斷位置之方向性問題，且能合
理解釋節理鋸齒數目對剪力強度之影響。(5) 3DEC模擬結果顯示剪動過程
中，確實先剪動角度大的鋸齒後剪動角度小的，即可以鋸齒上坡角的大小
作為接觸順序判斷依據。C-Y模式可進行因粗糙節瘤損傷而應變軟化之模
擬，其中粗糙度係數參數R可以控制尖峰強度與殘餘強度間曲線之下降率
，並影響尖峰剪力強度為控制軟化行為之主要因素。

This paper focuses on the failure behavior of post-peak
shearing for rock joints with multiple teeth. The joint surface
is simplified as a series of triangle teeth with different
inclinations. The failure mode for the components of joint
asperity is detected in turn according to Coulomb criterion. Two
basic failure modes of the slide-up and shear-off on tooth-
shaped asperity, and their shear stress-displacement behaviors
are used to superimpose the complete curve of general shear
failure mode. The proposed model is both verified by the
physical model testing and 3DEC analysis.It concludes that:(1)
The shearing behavior predominated by the first-order asperity
can be simulated by the proposed model based on the simplified
profile. This mathematical model can predict the shear strength
and shear-off position of teeth well, especially for case by
gradually damaging. The directional behavior and scale effect
affected by sequence of teeth can also be investigated through
this model.(2)The tooth with the highest inclination is
mobilized ahead of the lower teeth observed form 3DEC analysis.
The C-Y model in 3DEC can use to model the softening behavior
due to gradual damage of asperity. The softening behavior form
peak strength to residual behavior is primarily dominated by the
Roughness index R in 3DEC.