摘要
采用已开发的拉格朗日元方法、变形体离散元方法及虚拟裂纹模型耦合的连续-非连续方法,开展了开采及均布载荷条件下无粘结双层叠梁变形-开裂-垮落的数值模拟研究,研究了开采间隔(可比拟开采速度)、均布载荷(可比拟开采深度)及单梁叠放顺序的影响。叠梁由上软下硬或上硬下软两单梁构成。研究发现:随着开采间隔的增加,叠梁的位移值先增加后基本不变,首次开裂对应的开采距离减小,开裂位置增多,但增速变慢;随着均布载荷的增加,在开采过程中,叠梁先后呈现出弹性变形、开裂及垮落,离层变得不明显,叠梁的位移值增大,但不超过采高,首次开裂对应的开采距离减小,开裂位置有增多的趋势。当均布载荷较小时,上硬下软叠梁的开裂位置多于上软下硬叠梁的;但当均布载荷较大时,二者大小不确定,这反映了叠梁开裂后岩块之间复杂的相互作用。当均布载荷较大时,单梁叠放顺序的影响变小。
Numerical simulation of the deformation-cracking-collapsing of double-layer beams with no cohesions under uniform loading and excavation is conducted by use of a developed continuum-discontinuum method in which the Lagrangian element method,deformational discrete element method and fictitious crack model are coupled.Effects of the number of timesteps between two consequent excavations (in analogy to the mining velocity),the uniform loading (in analogy to the mining depth)and the order of single beams are studied.A double-layer beam is composed of an upper-soft single beam and a lower-hard single beam,or is composed of an upper-hard single beam and a lower-soft single beam.The following results are found.With an increase of the number of timesteps between two consequent excavations,values of displacements of double-layer beams firstly increase and then remain constant,the mining distance corresponding to the first cracking decreases,the number of new nodes due to cracking increases,but there is a slow increasing tendency.With an increase of the uniform loading,the elastic deformation and cracking are firstly found in the double-layer beams under excavation,and then the collapsing is found.Bed separation becomes less apparent,values of displacements of double-layer beams increase until the mining height is reached,the mining distance corresponding to the first cracking decreases and the number of new nodes due to cracking has an increasing tendency.At lower uniform loading,the number of new nodes due to cracking is greater for the upper-hard and lower-soft double-layer beam than for the upper-soft and lower-hard double-layer beam,while at higher uniform loading,no specific results is found,which reflects the complex interactions between rock blocks due to cracking of double-layer beams.At larger uniform loading,the influence of the order of single beams is negligible.
作者
王学滨
白雪元
侯文腾
芦伟男
Wang Xuebin;Bai Xueyuan;Hou Wenteng;Lu Weinan(Institute of Computational Mechanics,Liaoning Technical University,123000,Fuxin,China;College of Mechanics and Engineering,Liaoning Teetmical University,123000,Fuxin,China)
出处
《应用力学学报》
CAS
CSCD
北大核心
2018年第6期1326-1332,1424,1425,共9页
Chinese Journal of Applied Mechanics
基金
国家自然科学基金(51574144)
辽宁省百千万人才工程项目(2017)
关键词
双层叠梁
无粘结
均布载荷
采动
离层
开裂
垮落
开采间隔
double-layer beam
no cohesion
uniform loading
excavation
bed separation
cracking
collapsing
the number of timesteps between two consequent excavations
