Analysis of tailings dam failure mechanisms based on a continuum-discrete coupling method

作者：Yan, Qiong; Wu, Shun-Chuan; Song, Wei-Chao; Bao, De-Rong; Yang, Zhen-Wei

来源：International Journal of Earth Sciences and Engineering, 2015, 8(4): 1806-1814.

• Analysis
• Coupling algorithms
• Development tendency
• Numerical analysis models
• Particle rotations
• Slope stability analysis
• Tailings dam
• Tangential components

In this study, by using the background of the Xiangfen tailings dam failure in Shanxi Province in 2008, combined with an effective stress principle, the numerical analysis model of the dam was constructed by using a continuum-discrete coupling numerical analysis method. The continuum and discrete areas were analyzed using a finite difference FLAC grid and a discrete element PFC material, respectively, from the perspectives of macro and micro mechanics, and the failure mechanism of the dam was studied. Moreover, on the basis of the location of saturation line, a submerged unit weight of soil was introduced in the continuum-discrete coupling model. The failure feature of the tailings dam was acquired by the model in a hydrostatic action. According to this theory, a new application was gained by a continuum-discrete coupling method of the slope stability analysis. The results indicated that: (1) Both the submerged unit weight and the reasonable assumption of considering the dam material as soil mass containing water were employed, which could be used in the continuum-discrete coupling method, and the results were basically the same with the reasons of the dam failure. (2) Based on the characteristics of the displacement changes and the contact force chains during loading process, Region with drastic stress variety could be defined as coupling region which could provide a basis for selecting the coupling algorithm for the coupling region. (3) There exists a drastic local change of the contact force and the displacement near the loading boundary of the dam. Due to the effect of unloading and instability, the displacement showed a trend of increase. The variation of displacement of the discrete region coincided with loading direction, and the trend of contact chains was consistent with dam sliding direction. (4) The particle rotation could be characterized by tangential component of the contact force with the effect of clockwise and counter-clockwise direction. The normal component of the contact force was in agreement with the development tendency of displacement.

• 出版日期2015