JOURNAL OF YANGTZE RIVER SCIENTIFIC RESEARCH INSTI ›› 2016, Vol. 33 ›› Issue (4): 71-77.DOI: 10.11988/ckyyb.20150678

• ROCK-SOIL ENGINEERING • Previous Articles     Next Articles

Macro-and-meso Analysis of Failure Behavior of Rock-like Sampleswith Flaws Using a Numerical Method

KANG Shi-lei1, 2, YANG Jun-sheng1, YANG Feng1   

  1. 1.School of Civil Engineering, Central South University, Changsha 410083, China;
    32.School of CivilEngineering and Architecture, Changsha University of Science & Technology, Changsha 410114, China
  • Received:2015-08-13 Published:2016-04-01 Online:2016-04-08

Abstract: The aim of this research is to obtain the crack propagation and contact force variation of fractured rock under uniaxial loading. Gypsum was considered as similar material and was used to prepare fractured samples containing two different inclination angles. Destructive tests in uniaxial compression were performed on these samples using rigid testing machine. Failure process of the fractured samples was recorded. Furthermore, numerical model was created by a distinct element method, particle flow code 2D, and micro-parameters for this model were obtained through calibrating laboratory data. The relations between micro-crack increment and axial stress, and contact force change and crack initiation and propagation during loading was analyzed from macro-and-mesoscopic views. The crack development in numerical model and real samples was compared. Results show that contact force distribution within numerical model during loading gradually changes from uniform distribution to that concentrating around flaw tips and then micro-crack develops at these locations. As contact force concentrates intensively, micro-cracks slowly form into macro-cracks. The number of micro-cracks prior to peak axial stress increases slowly but rapidly after peak axial stress. Increase in the number of micro-cracks is related to that in axial stress. Before axial stress reaches the peak, axial stress stops increasing or even decreases slightly, but the number of micro-cracks grows steadily, which is corresponding to the crack propagation. PFC model could well simulate the mesoscopic change and crack propagation within samples during loading, which matches well with laboratory phenomenon.

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