1、翻译部分英文原文 Numerical Simulation of Coal Floor Fault Activation Influenced by Mining WANG Lian-guo,MIAO Xie-xing School of Sciences,China University of Mining&Technology,Xuzhou,Jiangsu 221008,China Abstract:By means of the numerical simulation software ANSYS,the activation regularity of coal floor faul
2、ts caused by mining is simulated.The results indicate that the variation in horizontal,vertical and shear stresses,as well as the horizontal and vertical displacements in the upper and the lower fault blocks at the workface are almost identical.Influenced by mining of the floor rock,there are stress
3、 releasing and stress rising areas at the upper part and at the footwall of the fault.The distribution of stress is influenced by the fault so that the stress isolines are staggered by the fault face and the stress is focused on the rock seam around the two ends of the fault.But the influence in fau
4、lt activation on the upper or the lower fault blocks of the workface is markedly different.When the workface is on the footwall of the fault,there is a horizontal tension stress area on the upper part of the fault;when the workface is on the upper part of the fault,it has a horizontal compressive st
5、ress area on the lower fault block.When the workface is at the lower fault block,the maximum vertical displacement is 5 times larger then when the workface is on the upper fault block,which greatly increases the chance of a fatal inrush of water from the coal floor. Key words:mining;fault activation
6、;simulation 1 Introduction In this paper we attempt to appraise the activation regularity and deformation of coal floor faults caused by mining.Damage mechanisms of rock around coal floor faults are described from different aspects and in different contexts110.Descriptions can,to some extent,intensi
7、fy our understanding of coal floor fault activation caused by mining.However, looking at the effect of these views,a mechanical analysis cannot achieve the purpose of pictures and clarity.For a more profound understanding of the regularity of fault activation caused by mining at the workface,we use
8、computers to make numerical simulations and obtain a series of valuable conclusions. 2 Numerical Calculation of Model Formation Considering the different fault activations influenced by the workface on the upper 中国矿业大学 2009 届本科生毕业设计 第111页 and lower fault blocks,we build two calculation models accord
9、ing to the state of the plane strain.Fig.1 is a calculation model(Model)of the workface on the lower fault block,showing the loading on the top of the terrane according to the distributional characteristics11 of mine pressure.Given the conditions of mining technology of the Qinan mine,the terrane 70
10、 m fore- and-aft the workface and 30 m deep under the coal floor is simulated.The lithology of the floor is Berea sandstone and the elastic modulus E=1.09104MPa,the Poissons ratio=0.34,the cohesion C=2.94MPa,the internal friction angle=35 and the density=2.5 kN/m3 .The calculation model of the workf
11、ace on the upper part of the fault(Model)is the same as that of Modelexcept that the abutment pressure ahead of the workface is on the upper part of the fault. 3 Numerical Simulation Results and Analysis For both models,the isoline graphs of horizontal, vertical and shear stresses as well as the hor
12、izontal and vertical displacements of modelsandhave been calculated and are plotted respectively as Figs.23. 3.1 Distribution characteristics of horizontal stresses Influenced by mining of the coal floor rock, there are horizontal stress releasing areas and rising areas at the upper part and at the
13、footwall of the fault. The distribution of horizontal stresses is influenced by the fault and it is obvious that the stress isolines are staggered by the fault face and the stress is concentrated on the rock seam around the two ends of the fault. In model I,stress is concentrated at the shallow part
14、 of the orebody at the footwall of the fault.The horizontal stress is 6.410 MPa.The horizontal stress under the fault face is 3.14.9 MPa.The lower part of mined-out areas on the lower fault block releases pressure,and may even turn to tension stress of about 0.5 MPa.But in the deeper part,the horizo
15、ntal stress turns to compressive stress and the value increases gradually. In model,the stress is concentrated at the lower part of the orebody on the lower fault block and the 中国矿业大学 2009 届本科生毕业设计 第 112页 中国矿业大学 2009 届本科生毕业设计 第 113页 horizontal stress becomes 14.627.5 MPa.The horizontal stress under
16、the fault face is 4.948.16 MPa.The lower part of the mined-out areas at the fault footwall releases pressure;the horizontal stress is 4.94 MPa. 3.2 Distributional characteristics of vertical stresses The distributions of vertical stresses are also influenced by faults.The stress isolines are staggered by the fault face.The s
