Dynamic centrifugal modelling tests on toppling rock slopes
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摘要: 使用相似材料分别制作了只含有非连续的层面和同时含有非连续的层面和非贯通的次级节理逆层岩体边坡小比例物理模型,进行离心机动力试验,研究边坡的动力响应和破坏机理以及非连续层面和次级节理对其的影响。试验结果证明：逆层岩体边坡地形放大效应受地震动力输入频率和振幅影响显著；次级节理对逆层边坡动力稳定性影响很大,含有次级节理的逆层岩体边坡动力稳定性明显低于不含次级节理的逆层岩体边坡；两种逆层边坡的破坏模式存在很大的区别,不含次级节理的边坡破坏从坡脚开始依次向后产生岩层的弯折破坏,而含有次级节理的边坡破坏从坡体中后部开始依次向坡脚岩层产生贯通破坏,贯通破坏面倾角明显高于不含次级节理边坡,并且呈明显的台阶状。Abstract: Two types of physical models for toppling rock slope with intermittent rock planes alone and with both rock planes and secondary rock joints are built of synthetic material, and tested in the centrifuge machine under different seismic loads. The dynamic response and failure mechanism of the two slope models are then recorded and analyzed. The results of the dynamic centrifuge tests reveal that: (1) the topographic amplification effect of the layered rock slope is related to the frequency and amplitude of the input seismic motion; (2) the secondary rock joints inside the rock slope serve to decrease the dynamic stability of the rock slope significantly; (3) the toppling rock slope without secondary rock joints fails in bending and toppling from the slope foot to the rock layer behind accordingly, while the slope with secondary rock joints fails firstly from the upper rock layer due to the penetration of secondary rock joints inside, and then to the underlying rock layers; () the dip angle of the final penetrating failure plane for the rock slope with secondary rock joints is much higher than the slope without secondary rock joints, and the failure plane forms in an obvious step-path shape.
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Keywords:
- toppling rock slope /
- dynamic /
- centrifugal modelling test /
- secondary rock joint
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[1] HOEK E. The design of a centrifuge for the simulation of gravitational force field in mine models[M]. CSIR National Mechanical Engineering Research Institute, 1965. [2] BRAY J W, GOODMAN R E. The theory of base friction models[C]//International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts. Pergamon, 1981, 18(6): 453-468. [3] ADHIKARY D P, DYSKIN A V, JEWELL R J, et al. A study of the mechanism of flexural toppling failure of rock slopes[J]. Rock Mechanics and Rock Engineering, 1997, 30(2): 75. [4] ZHANG G, ZHAO Y, SHI G H, et al. Toppling failure simulation of rock slopes by numerical manifold method[J]. Chinese Journal of Geotechnical Engineering, 2007, 29(6): 800-805. [5] JOSEPH P G, EINSTEIN H H, WHITMAN R V. A Literature Review of Geotechnical Centrifuge Modeling with Particular Emphasis on Rock Mechanics[R]. DTIC Document, 1988. [6] JOSEPH P G, EINSTEIN H H. Rock modeling using the centrifuge[R]. Massachusetts Inst of TECH Cambridge Dept of Civil Engineering, 1988.
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