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Abstract Joint surface morphology is one of the most important factors for peak shear strength of jointed rock. Artificial joints are used for direct shear tests under five levels of normal stresses，i. e. 0.5，1.0，1.5，2.0，3.0 MPa，to study the relationship between 3D morphology parameters and peak shear strength. Effective joint surface 3D mean angle ，surface roughness coefficient and the maximum possible contact area ratio are selected to describe the joint roughness. Scanning joint surface after each direct shear tests by TJXW–3D topography scanner and the above selective morphology parameters are calculated. A new peak shear dilation angle model is proposed with relationship to 3D morphology parameters of ， ， . Then，a new strength criterion with three morphology parameters is suggested for modeling the peak shear strength of rock joints. A comparison between the proposed models and the experimental results show a relatively good agreement. At last，the calculated results by the new criterion is compared to the well-known Barton?s criterion. It is shown that Barton?s criterion underestimates the observed peak strength.
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Received: 08 October 2011
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2013, Vol. 32 
