被动围压条件下岩石材料冲击压缩试验研究

摘要

In order to study the dynamic mechanical properties and failure behaviors of coalmine rock material under passive confining pressure condition,a 50 mm variable cross-section split Hopkinson pressure bar (SHPB ) apparatus was used to conduct impact compression tests in different loading rates under 45#steel sleeve constraint condition.The test results show that the ductility and damage resistance of rock material increase under passive confining pressure.The axial failure stress of rock specimens under passive confining pressure is about 1 .2 times as large as that without passive confining pressure.The failure strain is also about 1 to 2 times bigger than that without passive confining pressure.The radial stress increases with the growing of axial stain.The failure modes for rock specimens with or without passive confining pressure are different,and that with passive confining pressure is a compression-shear mode.%为研究煤矿岩石材料被动围压条件下动态力学性能和变形破坏规律，利用50mm变截面分离式Hopkin-son压杆（SHPB）试验装置，对45＃钢质套筒环向约束状态下煤矿岩石试件进行了不同加载速率冲击压缩试验。试验结果表明：被动围压条件下SHPB试验中，岩石试件的材料延性和抗破坏能力均得到增强，试件轴向应力是采用同种加载条件无围压SHPB试验时的1．2倍，破坏应变比无围压SHPB试验提高2～3倍，且径向应力随轴向应变增大总体呈上升趋势，试件破坏为压剪破坏模式，与无围压SHPB试验有所不同。