锚注加固体力学特征及破坏机理研究

Study on Mechanical Characteristics and Failure Mechanism of Anchored Grouted Solids

煤矿开采中的高应力多扰动问题日益突出,导致巷道常因不同程度的破碎而需要锚注支护,为探究锚注体承载特性以及破坏机理,制作了含不同粒径的无锚和加锚的注浆加固体,分别对其破坏特征、应力-应变曲线以及声发射信号特征进行了分析。研究表明,加锚后注浆加固体的破坏特征由拉伸断裂破坏转为整体以及区域性的剥落破坏,不同粒径锚注加固体试件破坏特征有所不同;锚杆对于注浆加固体的强化主要体现在峰后,增大了注浆加固体的延性和残余强度;声发射特征表征了锚注加固体的破裂过程,阶段性特征明显,随着粒径的增大,声发射活跃期的跨度增长,表明试件的断裂过程更缓慢,能量的渐进释放特征更明显。研究结果为山西某煤矿不同破碎情况的围岩的支护设计提供了参考。

The problem of high stress and multi-disturbance in coal mining is becoming more and more prominent,which leads to the need of anchored grouting support for roadways due to different degrees of breakage.In order to explore the bearing characteristics and failure mechanism of anchored grouting body,anchorless and anchored grouted solids with different particle sizes were made,and their failure characteristics,stress-strain curves and acoustic emission signal characteristics were analyzed respectively.The results show that the failure characteristics of grouted solids after anchoring change from tensile fracture failure to overall and regional spalling failure,and the failure characteristics of anchored grouted solids with different particle sizes are different.The reinforcement of the anchor rods to the grouted solids is mainly reflected in the post-peak,which increases the ductility and residual strength of the grouted solids.The acoustic emission characteristics characterize the fracture process of the anchored grouted solids,and the stage characteristics are obvious.With the increase of the particle size,the span of the acoustic emission active period increases,indicating that the fracture process of the specimen is slower and the gradual release of energy is more obvious.The research results provide a reference for the support design of surrounding rock with different crushing conditions in a coal mine in Shanxi.