加载速率对煤岩抗拉强度参数影响程度研究

Study of Loading Speed Influence on Tensile Strength Parameter of Coal Rock

加载速率效应是岩石材料力学特征的一个重要性质。采用室内实验方法,对煤岩进行不同加载速率下抗拉强度的影响程度研究。结果表明,加载速率的变化影响煤岩的抗拉强度及破坏模式,煤岩抗拉强度较低,具有低强度高脆性的特征,且受加载速率影响很大。加载速率较低会造成煤岩破坏过程沿着内部缺陷、天然裂隙破碎,有明显的延性特征。而加载速率较高时,拉伸破坏过程伴随煤粉的产生,呈明显的脆性破坏特征。该结论对分析煤岩受拉破坏条件及煤层气开发工程具有参考意义。

Loading speed effect is an important property of material mechanics characteristics of rock.The laboratory is used to study the impact of tensile strength of coal under different loading speed. The results show that the change of loading speed has an influence on the tensile strength and failure mode of coal, coal has a low tensile strength and low intensity high brittleness characteristics,it＇s highly affected by the loading speed. Lower loading speed will result in rock failure process along the internal defects, natural fissures broken,there is a significant ductility characteristics. While the loading speed is higher, tensile failure process is accompanied by the generation of pulverized coal and showed a brittle failure characteristics. The conclusion is referable for the analysis of the tensile failure conditions and the coalbed methane exploitation project.