Fractal characteristics of shear failure surface and mechanism of strength generation of soil-rock aggregate

被引：0
|
作者：
Liu X. [1 ,2 ]
Tu Y. [1 ,2 ]
Wang L. [1 ,2 ]
Feng H. [1 ,2 ]
Zhong Z. [1 ,2 ]
Lei X. [1 ,2 ]
Wang L. [1 ,2 ]
机构：
[1] School of Civil Engineering, Chongqing University, Chongqing
[2] Key Laboratory of New Technology for Construction of Cities in Mountain Area, Ministry of Education, Chongqing University, Chongqing
来源：
| 2017年 / Academia Sinica卷 / 36期
基金：
高等学校博士学科点专项科研基金; 中国国家自然科学基金;
关键词：
Fractal dimension; Shear failure surface; Soil test; Soil-rock aggregate; Strength generation mechanism;
D O I：
10.13722/j.cnki.jrme.2016.0967
中图分类号：
学科分类号：
摘要：
The large-scale direct shear test was conducted to soil-rock aggregate with different rock contents, water contents, rock lithology, initial void ratios and normal pressures. The shear strength mechanism of soil-rock aggregate was analyzed through the statistical analysis of fractal geometry of shear surface and the numerical simulation of particle interactions in the direct shear test with the particle flow code. The results indicate that the irregular topography of the shear failure surfaces of soil-rock aggregate are closely related to the existence of rock blocks and presents the fractal characteristics. The fractal dimension increases gradually with the decreasing of water content and normal pressure and the increasing of rock content and strength. If the rock content is more than 40%, the cohesion will be less than 30 kPa. The internal friction angle increases with the increasing of rock content and strength, the decreasing of water content, initial void ratio and normal pressure, and it has a positive correlation with the fractal dimension. The stress concentration happens near the rock particles. In the process of shearing, the contact force between the particles transfer mainly through the surface in the direction of shearing, but the contact surfaces back to the shear direction does not appear to transfer force. The internal friction angle φ is equal to the sum of θ0 and θi, where θ0 is the internal friction angle of the contact surface of particles on the shear plane related to the particle's properties and θi is the dip angle of the contact surfaces of particles related to the fractal dimension on the shear surface. The variation of shear strength parameters in the shear test can be explained with this mechanism. © 2017, Science Press. All right reserved.
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页码：2260 / 2274
页数：14
相关论文
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