标题：Deformation and failure behavior of three-body model composed of weak rock and strong coal
作者：Zhao, Zeng-Hui ;Wang, Wei-Ming
作者机构：[Zhao, Zeng-Hui ;Wang, Wei-Ming ] College of Civil Engineering, Shandong University of Science and Technology, Qingdao, China
来源：Electronic Journal of Geotechnical Engineering
摘要：A three-body combination model composed of soft rock and hard coal was introduced. Firstly, the stiffness matching relationship between single rock, coal and the combination model was deduced. Based on the strain softening model and Lagrangian element method, features of stress-strain curves under different stiffness ratio α between coal and rock were analyzed, and drawn the conclusions that the overall stiffness could be enhanced with the increasing of coal stiffness. If α≥1, coal stiffness has no influence on the peak strength of the combination model, and the strength can be reduced evidently with the decreasing of coal stiffness if α<1. The displacement reverse jumping phenomenon was detected by series of monitoring points arranged on the interface between rock and coal body, then its spatial-time effect was analyzed. Comparing the corresponding relationship between stress distribution and the concentration degree of the maximal unbalanced force, the damage evolution process of coal and rock in the combination model were presented, and some conclusions were draw as follows: shear failure and tensile failure could be produced in soft rock and coal respectively in combination mode, where the failure in coal lags behind the failure in soft rock; Displacement jumping on the interface between rock and coal could be regarded as the starting point of model failure. All the results and conclusions provide theoretical reference for the mechanism study of roof burst and floor heave in coal roadway. © 2013, EJGE.