摘要
利用传统方法测试岩土体内水分迁移时,往往要将原状土破碎和重塑,这会改变岩土体的结构,影响测试结果的真实性。利用核磁共振(NMR)技术具有无损测量材料中水分的特点,提出了一种新的测试方法。首先进行标定试验,将岩土试样放置在0~0.05 T的非均匀磁场中用不同的磁场强度测试,获得NMR信号量和试样水含量间的函数关系;然后对土样进行一维入渗试验与NMR测试,记录入渗时间、入渗水质量和不同位置条件下试样的NMR信号量;最后,根据标定试验所得NMR信号量与水含量之间的函数关系,计算获得试样中水分的空间分布。采用烘干法进行验证,试验结果与理论结果最大误差为4.05%。
When traditional methods are used to test soil moisture migration of rock and soil,the undisturbed soil is often broken and reshaped,which will change the structure of rock and soil and affect the authenticity of the test results.In order to solve this problem,a new testing method is proposed by using the characteristics of nuclear magnetic resonance(NMR)technology for nondestructive measurement of moisture in materials.Firstly,the calibration experiment was carried out to establish a functional relationship between the NMR signal amplitude and the position of a soil sample with unit water mass in a non-uniform magnetic field of 0~0.05 T.Second,a one-dimensional infiltration experiment and NMR test were conducted to record the infiltration time,water mass increase and NMR signal under different test positions.Then,using the functional relationship obtained in the calibration experiment,approximations of the moisture mass and its spatial distribution in the sample were obtained by comparing the the-oretical signal and the measured signals.Finally,the mudstone sample was cut into several parts to perform a verification experiment by oven drying,and the results showed that the error in water content was 4.05%or less.
作者
李东阳
周星辰
刘波
张千里
刘景宇
Li Dongyang;Zhou Xingchen;Liu Bo;Zhang Qianli;Liu Jingyu(School of Mechanics and Civil Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China;State Key Laboratory for Track Technology of High-speed Railway,China Academy of Rail way Sciences,Beijing 100081,China)
出处
《矿业科学学报》
CSCD
2023年第5期654-662,共9页
Journal of Mining Science and Technology
基金
国家自然科学基金(42172319,41771083)
中国矿业大学(北京)越崎青年基金(800015Z1200)。
关键词
水分迁移
无损检测
核磁共振
泥岩
water migration
nondestructive testing
nuclear magnetic resonance
mudstone
