基于核磁共振的不同含水状态砂岩动态损伤规律  

Dynamic damage laws of sandstone under different water bearing conditions based on nuclear magnetic resonance

作　　者：褚夫蛟 刘敦文[2] 陶明[2] 彭怀德[2] CHU Fu-jiao;LIU Dun-wen;TAO Ming;PENG Huai-de(School of Resources and Environmental Engineering, Shandong University of Technology, Zibo 255049, China;School of Resources and Safety Engineering, Central South University, Changsha 410083, China)

机构地区：[1]山东理工大学资源与环境工程学院,淄博255049 [2]中南大学资源与安全工程学院,长沙410083

出　　处：《工程科学学报》2018年第2期144-151,共8页Chinese Journal of Engineering

基　　金：国家自然科学基金资助项目(51404303);山东省自然科学基金资助项目(ZR2016EL06)

摘　　要：为研究不同含水状态岩石的动态损伤特性,制备干燥、半饱和、饱和3种不同含水状态的砂岩试样.采用分离式霍普金森压杆（SHPB）,以4种不同的低入射能对岩石进行损伤冲击试验.通过核磁共振测试实验对岩石试样进行孔隙扫描,获取岩石孔隙的T_2谱曲线、孔隙度以及孔隙成像等数据.通过试验发现：（1）冲击能量的增加导致岩石的平均应变率和强度的增大;（2）不同含水状态的岩石受到冲击后,孔隙度与孔隙度变化率均有不同程度的增加;（3）与冲击前相比,岩石的T2谱曲线有明显右移趋势,同时出现谱峰增加的现象,而且冲击能量越大,孔隙谱峰增加越明显;（4）核磁共振成像显示岩石孔隙数量和尺寸有明显的增加,展现出岩石内部孔隙扩展和演化的过程.To study the dynamic damage characteristics of sandstone under different water bearing conditions,three different kinds of samples with different moisture states（dry,semi-saturated,and saturated） were prepared. The impact damage of the rock was tested using a split Hopkinson pressure bar（SHPB） with four values of low incident energy. The T2 spectrum curves,porosity,and pore image of the samples were obtained by scanning the samples by nuclear magnetic resonance test. The results show the following：（1）an increase in the impact energy led to increased average strain rate and strength;（2） after impact,the porosity and porosity variation rate of every sample under different water bearing conditions increase with different amounts;（3） compared with the test before impact,T2 spectrum curve has obvious right movement trend and large pore peaks increase. The greater the impact energy increase,more obvious the large pore peaks increased are;（4） nuclear magnetic resonance images show that the number and size of pores increase,which show the expansion and evolution of pores in the rocks.

关 键 词：含水状态 动态损伤 冲击试验 核磁共振 孔隙度 T2谱曲线 

分 类 号：TU45[建筑科学—岩土工程]