Mechanical characteristics of intermittent jointed sandstone under triaxial compression

被引:0
|
作者
Deng H.-F. [1 ]
Pan D. [1 ]
Xu X.-L. [1 ]
Zhi Y.-Y. [1 ]
Duan L.-L. [1 ]
Yang C. [1 ]
Zhang Y.-N. [2 ]
机构
[1] Key Laboratory of Geological Hazards in Three Gorges Reservoir Area, China Three Gorges University, Ministry of Education, Yichang
[2] Central and Southern China Municipal Engineering Design &Research Institute Co. Ltd., Wuhan
关键词
Anisotropy; Destructive mode; Intermittent joint; Joint angle; Mechanical property;
D O I
10.11779/CJGE201911020
中图分类号
学科分类号
摘要
The mechanical properties of intermittent jointed rock mass directly affect the safety of engineering rock mass. In order to study its anisotropic mechanical properties and failure characteristics, the triaxial compression tests on the intermittent jointed sandstones with 6 joint inclination angles, 0°, 30°, 45°, 60°, 75° and 90°, are performed, and the effects of joint dip angle on the characteristics of deformation strength and failure modes of rock mass are analyzed. The results indicate that: (1) With the increase of confining pressure, the yield phase of stress-strain curve of intermittent jointed sandstone gradually becomes obvious, the peak and residual strengths gradually increase, and the characteristics of ductility are gradually obvious during destruction. (2) With the increase of joint dip, the deformation modulus, compressive strength, cohesion and internal friction angle of rock samples all present U-pattern change. (3) The joints have obvious induction and control effects on the formation and development of rock failure cracks. The fracture surfaces of the rock samples with different joint dip angles develop along the joint dip angle. When the joint dip angle is close to the calculated fracture one of the rock sample, the fracture surface of the rock sample is developed along the joint surface, and the deformation and strength parameters reach the minimum values. (4) With the increase of confining pressure, the difference of deformation and strength parameters of joints with different dip angles gradually decreases, and the anisotropy gradually weakens. (5) The failure modes of the intermittent jointed sandstone can be divided into three types: tensile failure, compound shear failure of fold line, and shear failure of joint surface, and the distribution of joint dip determines the deformation failure mode of sandstone under intermittent loading. The difference in deformation and failure modes determines the anisotropic characteristics of deformation and strength parameters of jointed sandstone. The research findings may provide a better reference for analyzing the anisotropic characteristics of jointed rock mass in engineering. © 2019, Editorial Office of Chinese Journal of Geotechnical Engineering. All right reserved.
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页码:2133 / 2141
页数:8
相关论文
共 32 条
  • [1] Wang S.-T., Liu H.-C., Zhang Z.-Y., Study on interaction and environmental effects of water rocks in large water bodies, Journal of Geological Hazard and Environmental Preservation, 8, 1, pp. 69-88, (1997)
  • [2] Sun G.-Z., The Foundation of Mechanics on Rock Mass Structure, (1988)
  • [3] Muller L., Rock Mechanics, (1981)
  • [4] Xiao W.-M., Deng R.-G., Fu X.-M., Et al., Model experiments on deformation and strength anisotropy of columnar jointed rock masses under uniaxial compression, Chinese Journal of Rock Mechanics and Engineering, 33, 5, pp. 957-963, (2014)
  • [5] Sun X.-S., Li J.-L., Wang L.-H., Et al., Study of ultrasonic test and uniaxial compression test of jointed rock masses, Rock and Soil Mechanicals, 35, 12, pp. 3473-3478, (2014)
  • [6] Sun X.-S., Li J.-L., Wang L.-H., Et al., Experimental Research on Anisotropic Mechanical Characteristic of Samples with Single Prefabricated joint, Rock and Soil Mechanicals, 35, pp. 29-34, (2014)
  • [7] Li J.-L., Wang L.-H., Sun X.-S., Et al., Experimental study on anisotropic mechanical characteristics of jointed rock masses under unloading condition, Chinese Journal of Rock Mechanics and Engineering, 33, 5, pp. 892-900, (2014)
  • [8] Wang Z.-Y., Duan P.-J., A new method for determining mechanical parameters of joints based on triaxial compressive test for rock mass, Rock and Soil Mechanicals, 32, 11, pp. 3219-3224, (2011)
  • [9] Wang L.-H., Bai J.-L., Li J.-L., Et al., Experimental study on uniaxial compression of rocks with non-through joints, Journal of Hydraulic Engineering, 45, 12, pp. 1410-1418, (2014)
  • [10] Wang L.-H., Bai J.-L., Sun X.-S., Et al., The triaxial loading and unloading mechanical properties of jointed rock masses with different joint connectivities, Chinese Journal of Rock Mechanics and Engineering, 34, 12, pp. 2500-2508, (2015)