岩石節理面之剪力強度主要受剖面粗糙度的影響,且具有明顯的異向性行為。本文基於統計觀念將節理面凹凸不平的分布以碎形布朗運動(fBm)軌跡模擬之,因此可以Hurst指數(H)來表示節理剖面之粗糙性質,H值具有方向性故與剪動方向有關,而優於一般常用的JRC或碎形維度D等係數表示法。文中,並以H值描述一人工節理特徵,與不同剪動方向所造成的異向性粗糙度與剪力強度。 This paper uses the Hurst exponent that based on the theory of fractional Brownian motion (fBm), to represent the anisotropic characteristic of the joint surface. The Hurst exponent that is dependent of the sequence of sampling can memory the past height history of asperity. Thus it can represent the anisotropic roughness characteristic of a profile according to the different sampling order and the shearing directions. Then the fractal dimension and the JRC can calculate from the Hurst exponent for a profile. Hence, the anisotropic shear strength of joints based on the Barton's empirical formula is also investigated.
關聯:
中華民國力學學會第二十屆全國力學會議論文集(二)=Proceedings of the 20th National Conference on Theoretical and Applied Mechanics (II)