Failure characteristics of three-body model composed of rock and coal with different strength and stiffness

作     者：赵增辉 王渭明 代春泉 严纪兴 Zeng-hui ZHAO;Wei-ming WANG;Chun-quan DAI;Ji-xing YAN

作者机构：山东科技大学矿山灾害预防控制省部共建国家重点实验室培育基地青岛266590 山东科技大学矿业与安全工程学院青岛266590 山东科技大学土木工程与建筑学院青岛266590 

出 版 物：《Transactions of Nonferrous Metals Society of China》 (中国有色金属学报（英文版）)

年 卷 期：2014年第24卷第5期

页      面：1538-1546页

核心收录：

学科分类：081901[工学-采矿工程] 0819[工学-矿业工程] 081903[工学-安全技术及工程] 08[工学] 

基　　金：Project(51174128)supported by the National Natural Science Foundation of China Project(20123718110007)supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China 

主　　题：three-body model composed of rock and coal strength near strong-weak interface local shear band plastic failure zone 

摘      要：Four different types of three-body model composed of rock and coal with different strength and stiffness were established in order to study the failure characteristics of compound model such as roof-coal-floor. Through stress analysis of the element with variable strength and stiffness extracted from the strong-weak interface, the tri-axial compressive strength of the weak body and strong body near the interface as well as the areas away from the contact surface was found. Then, on the basis of three-dimensional fast Lagrangian method of continua and strain softening constitutive model composed of Coulomb-Mohr shear failure with tensile cut-off, stress and strain relationship of the four three-body combined models were analyzed under different confining pressures by numerical simulation. Finally, the different features of local shear zones and plastic failure areas of the four different models and their development trend with increasing confining pressure were discussed. The results show that additional stresses are derived due to the lateral deformation constraints near the strong-weak interface area, which results in the strength increasing in weak body and strength decreasing in strong body. The weakly consolidated soft rock and coal cementation exhibit significant strain softening behavior and bear compound tension-shear failure under uni-axial compression. With the increase of confining pressure, the tensile failure disappears from the model, and the failure type of composed model changes to local shear failure with different number of shearing bands and plastic failure zones. This work shows important guiding significance for the mechanism study of seismic, rock burst, and coal bump.