不同煤块的强度变形特性及强度准则的回归方法  

STRENGTH AND DEFORMATION OF SPECIMEN FOR DIFFERENT COAL BLOCKS AND REGRESSION METHOD OF STRENGTH CRITERION

作　　者：尤明庆[1] 苏承东[2] 周英[2] 

机构地区：[1]焦作工学院机械系,焦作454159 [2]焦作工学院资源与材料工程系,焦作454159

出　　处：《岩石力学与工程学报》2003年第12期2081-2085,共5页Chinese Journal of Rock Mechanics and Engineering

基　　金：河南省创新人才基金资助项目。

摘　　要：与沉积岩的局部缺陷不同,煤层具有分布的裂隙和弱面,不仅影响强度,也会影响变形。煤样单轴压缩的强度和杨氏模量离散性很大,但两者具有明显的相关性。在围压下压缩时,闭合裂隙可以通过摩擦承载,使煤样强度和杨氏模量的离散性减小。不同煤块加工的试样强度不同,但围压对三轴强度的影响系数K相同,即内摩擦系数是一个材料参数,因而可以对不同煤块的试验结果进行联合回归。这不仅可以消除煤块的差异对内摩擦系数的影响,而且可以评价煤块强度的离散程度。Coulomb strength criterion means that the maximum axial stress of a given specimen increases with confining pressure linearly under the pseudo-triaxial compression. The strength of rock specimen is gotten after its destroy,so one specimen can give the strength under one confining pressure only. Unlike the local flaws in sedimentary,the fissures and weakness in coal are distributive,which influence both deformation and strength. Specimens form various coal blocks are of great difference in mechanics property. The uniaxial strength is 5.3～10.4 MPa and Youngs modulus is 2.36～3.17 GPa for specimens from Block A,strength 9.8～35.0 MPa and Youngs modulus 3.08～4.64 GPa for specimens from Block B,strength 5.9～20.7 MPa and Youngs modulus 2.34～4.55 GPa for specimens from Block E,respectively. The strength and Youngs modulus of specimens compressed uniaxially are of great dispersion,but there is a good correlation between them. Fissures in coal specimen compressed under confining pressure will close and axial stress is supported by the friction,which results in the decrement of dispersion of strength and Youngs modulus. The strengths of specimens from different coal blocks are different,but the coefficients of influence of confining pressure on the triaxial strength or the internal friction coefficients are the same for three coal blocks. The internal friction coefficient is a material parameter and the cohesion is a strength property of coal block. So all the strengths of different coal blocks,no matter how many specimens are made,can be regressed jointly,and the strength property of coal blocks can be known as well. The strength criterion can be decided from various blocks.

关 键 词：煤块 岩石力学 强度变形 离散性 回归分析 内摩擦系数 

分 类 号：TD313.1[矿业工程—矿井建设]