D0L:10.13374/.issn1001-053x.2013.10.002 第35卷第10期 北京科技大学学报 Vol.35 No.10 2013年10月 Journal of University of Science and Technology Beijing 0ct.2013 粗、细粒径花岗岩冻融损伤机理及其演化规律 周科平，张亚民☒，李杰林，许玉娟 中南大学资源与安全工程学院，长沙410083 ☒通信作者，E-mail:laozhang1987@126.com 摘要通过粗、细两种颗粒花岗岩的冻融循环试验和岩石力学试验，研究了不同粒径岩石的冻融循环作用对岩石物理 力学特性的影响.利用核磁共振技术对冻融循环前后的岩样进行检测，得到了横向弛豫时间谱的变化和岩样核磁共振成 像，分析了岩样在冻融前后的孔隙度变化、空隙结构及分布的演化特性等。采用宏观唯象损伤理论和自洽理论对不同粒 径花岗岩在冻融条件下的宏、细观损伤演化规律进行了分析.研究发现在冻融循环作用下，岩石内部的孔隙逐渐增多， 不断造成岩石的强度损失：损伤模型的计算值与实际相符，但不同损伤理论对花岗岩损伤程度趋势变化的反应存在差 异：细颗粒花岗岩呈现出较高冻融耐久性. 关键词花岗岩：冷冻：融化：劣化：核磁共振 分类号P588.12;TU458+.2 Degradation mechanism and evolutionary pattern of granites with coarse and fine grains in freezing-thawing condition ZHOU Ke-ping,ZHANG Ya-min,LI Jie-lin,XU Yu-juan School of Resource and Safety Engineering,Central South University,Changsha 410083,China Corresponding author,E-mail:laozhang1987@126.com ABSTRACT The influence of freezing and thawing cycles on the physical and mechanical properties of granites with coarse and fine grains was studied by freezing and thawing cycle experiment and rock mechanic test.Rock samples were detected by nuclear magnetic resonance(NMR),their transverse relaxation time spectra and NMR images were got before and after freezing and thawing cycle experiment,and the porosity variation,pore structure and evolution laws were discussed.The macro phenomenological theory and the self-consistency theory were used to analyze the degradation principle of rock samples in macro and micro scales,respectively.It is found that the number of pores increases in the action of freezing and thawing cycles,which weakens the strength of rock samples.The theoretical values of damage models are in consistence with experimental data,but different damage theories show different results about the development of damage tendency.Granite with fine grains shows a better durability in the action of freezing and thawing cycles. KEY WORDS granite;freezing;thawing:deterioration;nuclear magnetic resonance 岩石是自然界中各种矿物的集合体，由于组成 特殊环境下受到温度效应、荷载作用和化学侵蚀等 岩石的各种矿物成分在物理力学性质上的差异以及 多种因素的交互组合影响作用，导致材料性能的不 岩石内部存在的节理、微裂隙、粒间空隙和空洞等 可逆劣化及承载能力下降，内部的结构、构造处于 缺陷，决定了岩石是一种非均匀材料.寒区岩体在 一种缓慢而长期的损伤破坏过程当中，最终引起寒 收稿日期：2012-08-16 基金项目：国家自然科学基金资助项目(61074178)：高等学校博士学科点专项科研基金资助项目(20090162110036)第 35 卷 第 10 期 北 京 科 技 大 学 学 报 Vol. 35 No. 10 2013 年 10 月 Journal of University of Science and Technology Beijing Oct. 2013 粗、细粒径花岗岩冻融损伤机理及其演化规律 周科平，张亚民 ，李杰林，许玉娟 中南大学资源与安全工程学院，长沙 410083 通信作者，E-mail: laozhang1987@126.com 摘 要 通过粗、细两种颗粒花岗岩的冻融循环试验和岩石力学试验，研究了不同粒径岩石的冻融循环作用对岩石物理 力学特性的影响. 利用核磁共振技术对冻融循环前后的岩样进行检测，得到了横向弛豫时间谱的变化和岩样核磁共振成 像，分析了岩样在冻融前后的孔隙度变化、空隙结构及分布的演化特性等. 采用宏观唯象损伤理论和自洽理论对不同粒 径花岗岩在冻融条件下的宏、细观损伤演化规律进行了分析. 研究发现在冻融循环作用下，岩石内部的孔隙逐渐增多， 不断造成岩石的强度损失；损伤模型的计算值与实际相符，但不同损伤理论对花岗岩损伤程度趋势变化的反应存在差 异；细颗粒花岗岩呈现出较高冻融耐久性. 关键词 花岗岩；冷冻；融化；劣化；核磁共振 分类号 P588.12; TU458+.2 Degradation mechanism and evolutionary pattern of granites with coarse and fine grains in freezing-thawing condition ZHOU Ke-ping, ZHANG Ya-min , LI Jie-lin, XU Yu-juan School of Resource and Safety Engineering，Central South University, Changsha 410083, China Corresponding author, E-mail: laozhang1987@126.com ABSTRACT The influence of freezing and thawing cycles on the physical and mechanical properties of granites with coarse and fine grains was studied by freezing and thawing cycle experiment and rock mechanic test. Rock samples were detected by nuclear magnetic resonance (NMR), their transverse relaxation time spectra and NMR images were got before and after freezing and thawing cycle experiment, and the porosity variation, pore structure and evolution laws were discussed. The macro phenomenological theory and the self-consistency theory were used to analyze the degradation principle of rock samples in macro and micro scales, respectively. It is found that the number of pores increases in the action of freezing and thawing cycles, which weakens the strength of rock samples. The theoretical values of damage models are in consistence with experimental data, but different damage theories show different results about the development of damage tendency. Granite with fine grains shows a better durability in the action of freezing and thawing cycles. KEY WORDS granite; freezing; thawing; deterioration; nuclear magnetic resonance 岩石是自然界中各种矿物的集合体，由于组成 岩石的各种矿物成分在物理力学性质上的差异以及 岩石内部存在的节理、微裂隙、粒间空隙和空洞等 缺陷，决定了岩石是一种非均匀材料. 寒区岩体在 特殊环境下受到温度效应、荷载作用和化学侵蚀等 多种因素的交互组合影响作用，导致材料性能的不 可逆劣化及承载能力下降，内部的结构、构造处于 一种缓慢而长期的损伤破坏过程当中，最终引起寒 收稿日期：2012-08-16 基金项目：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) DOI:10.13374/j.issn1001-053x.2013.10.002