冻融花岗岩细观损伤演化的核磁共振  

Granite microstructure deterioration characteristic under condition of freezing-thawing based on NMR technology

作　　者：周科平[1] 张亚民[1] 李杰林[1] 许玉娟[1] 

机构地区：[1]中南大学资源与安全工程学院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2013年第8期3384-3389,共6页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51074178);高等学校博士学科点专项科研基金资助项目(20090162110036)

摘　　要：为研究岩石经历冻融循环后的细观损伤演化特征,选取寒区花岗岩岩心为试样,划分为5组,在饱和状态下分别对各组进行多轮冻融循环试验,利用核磁共振技术在每轮冻融循环结束之后对试样进行检测,获得岩石在不同冻融阶段的试件表面变化、质量变化、弛豫时间T2分布、孔隙度变化和孔隙分布及结构成像等。通过对冻融循环数与试样质量、孔隙度等之间的关系进行分析对比,表明试样在冻融循环作用下岩石内部孔隙不断损伤扩展,孔隙度提高,使得试样在饱和状态下的质量增加。通过对比不同轮次核磁共振结构成像图,结合孔隙分布和孔隙度增长规律,总结岩石在冻融循环试验中的细观损伤的演化模式,为研究寒区岩体的破坏机理提供一定的理论依据。To get the microscopic damage of rock, granite rock from cold region was selected as samples （saturated） to conduct freeze-thaw cycle experiment of different cycle index. Nuclear magnetic resonance （NMR） technology was used to detect microscopic damage of rock samples after each cycle group. The changes of samples＇ surface, variation of mass, T2 spectrum, porosity changes distribution and porosity NMR images of different stage were obtained. The results indicate that pores in the rock expand and porosity increases, mass of samples in the condition of saturated also grows with the growing cycle numbers. Degradation evolution mode is obtained by comparative analysis of NMR images and porosity distribution and its increasing principle of different cycle index. This research will provide theoretical basis for the study of rock deterioration principle in cold region.

关 键 词：冻融循环 核磁共振 细观损伤 核磁共振成像 

分 类 号：TU458.2[建筑科学—岩土工程]