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| MODEL EXPERIMENTS ON DEFORMATION AND STRENGTH ANISOTROPY OF COLUMNAR JOINTED ROCK MASSES UNDER UNIAXIAL COMPRESSION |
| XIAO Weimin1，DENG Ronggui1，FU Xiaomin2，WANG Congyan2 |
(1. Department of Geotechnical Engineering，Southwest Jiaotong University，Chengdu，Sichuan 610031，China；
2. State Key Laboratory of Geohazard Prevention and Geoenvironment Protection，Chengdu University of Technology，
Chengdu，Sichuan 610059，China) |
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Abstract The columnar jointed rock mass is a typical structural rock mass. Due to the columnar joints，the deformation and the strength of columnar jointed rock mass exhibit remarkable anisotropy. In order to investigate the mechanical anisotropy of columnar jointed rock mass，the mixtures of plaster，cement and water were used to make cylindrical columnar jointed specimens with different dip angles ranging from 0°to 90° for uniaxial compression tests. The deformation modulus and uniaxial compression strength of the columnar jointed specimens with different dip angles were obtained. The anisotropy curves of deformation and strength with different dip angles ? were plotted and the anisotropic characteristics of deformation and strength were analyzed. The shape of the anisotropy curves of deformation and strength resembles the letter“U”. Both the deformation modulus and uniaxial compression strength have the minimum value at ? =30°，and reach the maximum value at ? = 90°. The anisotropy ratio of the strength is as high as 1.5，which indicates a high anisotropy. The deformation modulus of columnar jointed rock mass reaches the minimum value when ? is between 30°and 60°，and the corresponding lateral strain ratio become greater than 0.5. Furthermore，the columnar jointed specimen have four types of failure modes under uniaxial compression and the failure mechanisms were discussed.
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Received: 22 July 2013
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2014, Vol. 33 
