摘要
利用分离式霍普金森压杆(SHPB)对微波加热后的湖北麻山花岗岩进行动态冲击压缩试验,研究了不同含水状态下花岗岩动态力学性质及破碎特征,对比分析了不同微波加热参数对其力学性能的影响,揭示了微波对花岗岩强度弱化的作用机制。研究结果表明:当微波功率小于2.6 kW时,岩石强度降低是由微波生热及岩石内部水分共同作用造成的;当微波功率大于2.6 kW时,热的劣化占主导作用。花岗岩试件在达到应变均匀变化状态时所需时间较长,因此可认为是在近似恒应变率下进行的冲击压缩试验;在一定微波照射功率范围内,花岗岩动态峰值应力随着冲击气压的升高呈增大趋势,且冲击气压每增加0.05 MPa,岩石强度提高10%~20%;在一定微波照射功率范围内,花岗岩动态抗压强度折减程度远小于其静态抗压强度折减程度;在微波加热和荷载的共同作用下,岩石多为轴向拉伸及压碎破坏,且随着微波加热功率及荷载的增大,花岗岩破坏程度增大,碎块愈加细致且均匀。
The dynamic impact compression test of Hubei Mashan granite heated by microwave was carried out using a split Hopkinson compression bar(SHPB).The dynamic mechanical properties and crushing characteristics of granite under different water-containing states were studied.The effects of different microwave heating parameters on its mechanical properties were compared and analyzed,and the mechanism of microwave weakening the strength of granite was revealed.The results show that when the microwave power is less than 2.6 kW,the decrease of rock strength is caused by microwave heat generation and water in the rock.When the microwave power is greater than 2.6 kW,thermal degradation plays a leading role.It takes a lot of time for granite specimens to reach the state of uniform strain change,so it can be considered as an impact compression test at an approximately constant strain rate.Within a certain microwave irradiation power range,the dynamic peak stress of granite increases with the increase of impact pressure,and the rock strength increases by 10%-20%with the increase of impact pressure by 0.05 MPa.In a certain microwave power range,the reduction degree of dynamic compressive strength of granite is much less than that of static compressive strength.Under the combined action of microwave heating and load,the rock failure is mostly axial tensile and crushing failure.With the increase of microwave heating power and load,the greater the failure degree of granite,the more detailed and uniform the fragments are.
作者
朱清耀
戴俊
贠菲菲
翟惠慧
张敏
冯立人
ZHU Qingyao;DAI Jun;YUN Feifei;ZHAI Huihui;ZHANG Min;FENG Liren(School of Architecture and Civil Engineering,Xi'an University of Science and Technology,Xi'an 710054,China;Shaanxi Modern Architectural Design and Research Institute,Xi'an 710043,China;School of Civil Engineering and Architecture,Xi'an Polytechnic University,Xi'an 710021,China)
出处
《采矿与岩层控制工程学报》
北大核心
2022年第1期56-68,共13页
Journal of Mining and Strata Control Engineering
基金
国家自然科学基金资助项目(51174159)
陕西省自然科学基础研究计划资助项目(2017JQ5069)
陕西省教育厅专项科学研究基金资助项目(15JK1471)。
关键词
微波照射
花岗岩
分离式霍普金森压杆
动力学性能
破碎特征
microwave irradiation
granite
split Hopkinson pressure bar
dynamic performance
crushing characteristics
