摘要
针对寒区隧道围岩冻融损伤问题,文章以辽宁某在建隧道为工程背景,采用核磁共振和声波检测技术对不同冻融循环次数后的隧道围岩(砂岩)进行检测试验,同时对检测后的试样还进行了单轴加载试验,分析了冻融作用对隧道围岩加载前后的损伤劣化机制。结果表明:随着冻融循环次数的逐渐增加,试样的T_(2)谱总面积逐渐增大,核磁共振T_(2)谱信号逐渐增强,小孔隙T_(2)谱面积占比逐渐提升,试样的纵波波速逐渐减小,应力-应变曲线的压密阶段和塑性屈服阶段在整个加载曲线中的占比逐渐增大,峰值强度、弹性模量均呈之间递减变化趋势,抗压强度、弹性模量均随T_(2)谱面积的增大逐渐减小,随纵波波速的增大逐渐增大。
Freeze⁃thaw damage problem in cold regions tunnel surrounding rock,based on a tunnel under construction in Liaoning,this article adopted nuclear magnetic resonance(NMR)and acoustic detection techniques to test tunnel surrounding rock after different freeze⁃thaw cycles(sandstone).At the same time,to the article also carried out a uniaxial loading test on the samples,and analyzed the damage degradation mechanism of freeze thaw on tunnel surrounding rock before and after loading.The results showed that with the increase of freeze⁃thaw cycles,the T_(2)spectrum of sample area increased gradually,nuclear magnetic resonance T_(2)spectrum signal gradually strengthened,small pore T_(2)spectrum area proportion gradually enhanced,sample of compressional wave velocity decreased,and the stress⁃strain curve of pressure dense phase and plastic yielding phase proportion in the whole load curve increased gradually.The peak strength and elastic modulus showed a decreasing trend.The compressive strength and elastic modulus both decreaseed with the increase of T_(2) spectral area and increased with the increase of p⁃wave velocity.
作者
高越
GAO Yue(China Railway 19th Bureau Group 1st Co.,Ltd.,Liaoyang 111000,Liaoning,China)
出处
《资源信息与工程》
2022年第1期97-100,103,共5页
Resource Information and Engineering
关键词
隧道工程
冻融循环
核磁共振
声波检测
砂岩
tunnel engineering
freeze⁃thaw cycle
nuclear magnetic resonance
acoustic detection
sandstone
