含水砂岩和大理岩动态冲击性能分析  

Dynamic impact performance of water-bearing sandstone and marble

作　　者：谭昊 巫绪涛[2] TAN Hao;WU Xutao(Zhongyan Technology Co., Ltd., Beijing 100041, China;School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei 230009, China)

机构地区：[1]北京中岩大地科技股份有限公司,北京100041 [2]合肥工业大学土木与水利工程学院,安徽合肥230009

出　　处：《合肥工业大学学报（自然科学版）》2022年第6期793-800,824,共9页Journal of Hefei University of Technology：Natural Science

基　　金：国家重点研发计划资助项目(2016YFC0600802)。

摘　　要：文章通过对烘干、天然含水和自由吸水状态下的灰砂岩、红砂岩和大理岩进行分离式霍普金森压杆(split Hopkinson pressure bar,SHPB)实验,分析应变率与动态抗压强度的关系以及入射能与耗散能的关系,以天然含水状态岩石动态抗压强度为参照,分析烘干、自由吸水状态下的岩石动态抗压强度变化情况。研究发现,自由吸水状态灰砂岩和红砂岩的动态抗压强度明显降低,大理岩动态抗压强度变化不大;烘干状态下,大理岩动态抗压强度明显降低,灰砂岩动态抗压强度变化不大,红砂岩动态抗压强度明显提高;岩石单轴抗压强度大于56.16 MPa后,自由吸水状态显著降低其动态抗压强度,岩石单轴抗压强度大于74.53 MPa后,自由吸水岩石的动态抗压强度对应变率变化更加敏感。因此,在较坚硬的砂岩中进行动态冲击类型的机械破岩工程中,提高冲击速度的同时,尽量提高岩石的含水率,破岩效果更好;相比于提高其含水率,对大理岩提前进行烘干处理,破岩效果会更好。Through the split Hopkinson pressure bar(SHPB)experiment on limestone,red sandstone and marble under drying,natural water containing and free water absorption conditions,the relationship between strain rate and dynamic compressive strength,as well as incident energy and dissipated energy is analyzed.Then taking the dynamic compressive strength of rock under natural water containing state as a reference,the change of dynamic compressive strength of rock under drying and free water absorption state is analyzed.It is found that the dynamic compressive strength of limestone and red sandstone under free water absorption state is significantly reduced,and the influence on the dynamic compressive strength of marble is not significant;Under drying state,the dynamic compressive strength of marble is obviously reduced,the dynamic compressive strength of limestone changes little,and the dynamic compressive strength of red sandstone increases significantly.When the uniaxial compressive strength is greater than 56.16 MPa,the dynamic compressive strength of rock is significantly reduced under the state of free water absorption;when the uniaxial compressive strength is greater than 74.53 MPa,the dynamic compressive strength of free water absorbing rock is more sensitive to the change of strain rate.Therefore,in the dynamic impact typed mechanical rock breaking engineering for hard sandstone,it is better to increase the impact speed and the water content of rock as much as possible.Compared with the increase of water content,the effect of drying marble in advance will be better.

关 键 词：冲击凿岩 含水围岩 分离式霍普金森压杆(SHPB) 耗散能 

分 类 号：O347.1[理学—固体力学]