Research on creep disturbance characteristics and strength limit neighborhood of coal-rock combination body with different coal heights
HUANG Zikang;LI Zhun;WANG Jichao;MA Shiji;YANG Yumo
煤炭科学技术研究院有限公司煤矿灾害防控全国重点实验室北京市煤矿安全工程技术研究中心华北科技学院 应急技术与管理学院鄂尔多斯市昊华红庆梁矿业有限公司
为了研究不同煤体高度煤岩组合体的蠕变扰动特性,运用岩石流变扰动效应试验系统,进行了煤岩组合体的单轴压缩蠕变扰动试验,并采用ABAQUS对试验结果进行了数值模拟验证;结果显示,煤体与岩体高度比1∶4、1∶2和2∶1的3种组合体进入强度极限邻域内的阈值分别为30、25、20 MPa,对应的强度极限右邻域阈值宽度分别为5、3、2 MPa。试验结果表明:低应力水平下,外界扰动不会对煤岩组合体的整体破坏产生较大影响,而在高应力水平下,组合体受外界扰动影响较大;组合体长期强度随煤体高度增加不断减小,且随扰动次数增加,组合体整体逐渐由脆性破坏转变为延性破坏;只有进入强度极限邻域内时,煤岩组合体才对外界扰动较为敏感,且煤体高度越高,扰动次数越多,组合体整体进入强度极限邻域内的阈值越低,强度极限右邻域阈值宽度也越小。
In order to study the creep disturbance characteristics of coal-rock combination body with different coal body heights, the uniaxial compression creep disturbance test of coal-rock combination body was carried out by using the rock rheological disturbance effect test system, and the test results were verified by ABAQUS numerical simulation. The test results show that the thresholds of the three kinds of combination bodies with coal and rock mass height ratios of 1∶4, 1∶2 and 2∶1 entering into the strength limit neighborhood are 30 MPa, 25 MPa and 20 MPa, respectively, and the corresponding strength limit right neighborhood threshold widths are 5 MPa, 3 MPa and 2 MPa, respectively. The test results show that under the low stress level, the external disturbance does not have a great impact on the overall failure of the coal-rock combination body, while under the high stress level, the combination body is greatly affected by the external disturbance; the long-term strength of the combination body decreases with the increase of coal height, and with the increase of disturbance times, the whole combination body gradually changes from brittle failure to ductile failure; the coal-rock combination body is more sensitive to external disturbances when it only enters the strength limit neighborhood, and the higher the coal height, the more the number of disturbances, the lower the threshold of the combination body entering the strength limit neighborhood as a whole, and the smaller the threshold width of the right neighborhood of the strength limit.
coal-rock combination body;creep disturbance;numerical simulation;disturbance sensitive threshold;strength limit neighborhood
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会