基于核磁共振技术的白云岩卸荷损伤与渗透特性试验研究

doi:10.13722/j.cnki.jrme.2019.0628

摘要
图/表
参考文献
相关文章 (15)

全文: PDF (1201 KB) HTML (1 KB)
输出: BibTeX | EndNote (RIS)

摘要深部岩体工程往往面临开挖卸荷效应日益增强、节理裂隙愈加发育、强地下水环境等复杂的工程地质问题。为掌握开挖卸荷对岩体力学特性和渗透特性的影响规律，以白云岩为试验对象，开展不同卸荷围压比△σ(100%，90%，60%，30%，0)和不同孔隙压力P(0，5，10 MPa)下的三轴卸荷渗透试验，并借助核磁共振技术对试验前后的岩石孔隙度进行测试，以阐述岩石卸荷损伤及渗透特性演变规律。试验结果表明：不同孔隙水压下岩石的卸荷变形规律基本一致，均经历平稳过渡→匀速增长→快速增加→急剧扩张4个阶段，且岩石所能承受的应变极限几乎相等，与之相对应，卸荷过程中岩石渗透率亦具有缓慢渗透→稳定渗透→加速渗透→渗透突增四级演变特征；孔隙水压的存在加速了岩石内部裂隙的产生和扩展，孔隙水压力越大，孔隙度越大，渗透率越大，孔隙度、变形和渗透率具有显著的正相关，但相比孔隙水压，卸荷围压比对岩石变形影响更大，当△σ＞60%后，岩石中的裂隙数量和贯通程度会发生突增，说明强烈的开挖卸荷可导致岩体宏观破坏面的形成进而使渗透能力急剧增大，这对地下水丰富地段的地下工程施工安全不利。

	服务

	把本文推荐给朋友
	加入我的书架
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章
	李克钢1
	2
	杨宝威1
	秦庆词1

关键词 ：岩石力学, 核磁共振, 孔隙水压, 卸荷, 损伤演化, 渗透特性

Abstract：Deep rock mass engineering is facing complex engineering geological problems such as increasing unloading effect of excavation，growing joints and fissures，and strong groundwater environment. In order to grasp the influence law of excavation unloading on mechanical properties and permeability characteristics of rock mass，take the Dolomite as the experiment object，the triaxial unloading tests under different unloading confining pressure ratio ??(100%，90%，60%，30%，0) and pore water pressure P(0，5，10 MPa) were conducted through GCTS rock mechanics test system，and the rock porosity before and after the test was measured by nuclear magnetic resonance(NMR) technology. The test results show that the unloading deformation laws of rock under different pore water pressures are basically the same，which all have four stages：smooth transition，uniform growth，fast growth and rapid expansion，and the strain limit of rock is almost equal. Correspondingly，the rock permeability during unloading process also has four stages：slow permeability，stable permeability，accelerated permeability and sudden-increase permeability. The existence of pore water pressure accelerates the generation and expansion of cracks in rocks. The larger the pore water pressure is，the larger the porosity is，and the larger the permeability is，there are a significant positive correlation among porosity，deformation and permeability. However，unloading confining pressure ratio has more influence on rock deformation than pore water pressure，when ??＞60%，the number and penetration of cracks in rock will increase sharply，it shows that strong excavation unloading can lead to the formation of macro-failure surface of rock mass and then increase the permeability，which is not conducive to the construction safety of underground engineering in rich groundwater areas.

Key words： rock mechanics nuclear magnetic resonance(NMR) porewater pressure unloading damage evolution permeability

引用本文:

李克钢1，2，杨宝威1，秦庆词1. 基于核磁共振技术的白云岩卸荷损伤与渗透特性试验研究[J]. 岩石力学与工程学报, 2019, 38(S2): 3493-3502.
LI Kegang1，2，YANG Baowei1，QIN Qingci1. Experimental study on unloading damage and permeability of dolomite based on nuclear magnetic resonance technique. , 2019, 38(S2): 3493-3502.

链接本文:

http://rockmech.whrsm.ac.cn/CN/10.13722/j.cnki.jrme.2019.0628 或 http://rockmech.whrsm.ac.cn/CN/Y2019/V38/IS2/3493

[6]	刘先珊，林耀生，孔建. 考虑卸荷作用的裂隙岩体渗流应力耦合研究[J]. 岩土力学，2007，28(增1)：192–196.(LIU Xianshan，LIN Yaosheng，KONG Jian. Study of hydro-mechanical coupling of fractured rock masses considering unloading effect[J]. Rock and Soil Mechanics，2007，28(Supp.1)：192–196.(in Chinese))
[16]	张雪颖，阮怀宁. 高围压高水压条件下大理岩卸围压变形破坏与能量特征[J]. 水利水电科技进展，2009，29(5)：5–8.(ZHANG Xueying，RUAN Huaining. Unloading deformation failure and energy properties of marble under high confining pressure and high water pressure[J]. Advances in Science and Technology of Water Resources，2009，29(5)：5–8.(in Chinese))
[8]	陈秀铜，李璐. 高围压、高水压条件下岩石卸荷力学性质试验研究[J]. 岩石力学与工程学报，2008，27(增1)：2 694–2 699.(CHEN Xiutong，LI Lu. Experimental study of unloading mechanical properties of rock under high confining pressure and high water pressure[J]. Chinese Journal of Rock Mechanics and Engineering，2008，27(Supp.1)：2 694–2 699.(in Chinese))
[18]	张元中，肖立志. 单轴载荷下岩石核磁共振特征的实验研究[J]. 核电子学与探测技术，2006，26(6)：731–735.(ZHANG Yuanzhong，XIAO Lizhi. Experimental study of the NMR characteristics in rock under uniaxial load[J]. Nuclear Electronics and Detection Technology，2006，26(6)：731–735.(in Chinese))
[1]	仵彦卿，张倬元. 岩体水力学导论[M]. 成都：西南交通大学出版社，1995：1–3.(WU Yanqing，ZHANG Zhuoyuan. Introduction to rock mass hydraulics[M]. Chengdu：Southwest Jiaotong University Press，1995：1–3.(in Chinese))
[11]	刘新荣，刘俊，李栋梁，等. 不同水压与初始卸荷水平下砂岩的力学特性及卸荷本构模型[J]. 煤炭学报，2017，42(10)：2 592–2 600. (LIU Xinrong，LIU Jun，LI Dongliang，et al. Unloading mechanical properties and constitutive model of sandstone under different pore pressures and initial unloading levels[J]. Journal of China Coal Society，2017，42(10)：2 592–2 600.(in Chinese))
[9]	唐浩，李天斌，陈国庆，等. 水力作用下砂岩三轴卸荷试验及破裂特性研究[J]. 岩土工程学报，2015，37(3)：519–525.(TANG Hao，LI Tianbin，CHEN Guoqing，et al. Triaxial unloading tests on rupture characteristics of sandstone under hydro-mechanical coupling conditions[J]. Chinese Journal of Geotechnical Engineering，2015，37(3)：519–525.(in Chinese))
[19]	杜晓波，付成伟，纪媛，等. 稳态核磁共振实验中弛豫时间T2的测量方法[J]. 物理实验，2018，38(11)：17–19.(DU Xiaobo，FU Chengwei，JI Yuan，et al. Measuring the relaxation time T2 in nuclear magnetic resonance experiment[J]. Physics Experimentation，2018，38(11)：17–19.(in Chinese))
[2]	谢和平，张泽天，高峰，等. 不同开采方式下煤岩应力场–裂隙场–渗流场行为研究[J]. 煤炭学报，2016，41(10)：2 405–2 417. (XIE Heping，ZHANG Zetian，GAO Feng，et al. Stress-fracture- seepage field behavior of coal under different mining layout[J]. Journal of China Coal Society，2016，41(10)：2 405–2 417.(in Chinese))
[3]	王如宾，徐波，徐卫亚，等. 不同卸荷路径对砂岩渗透性演化影响的试验研究[J]. 岩石力学与工程学报，2018，37(11)：697–701.(WANG Rubin，XU Bo，XU Weiya，et al. Experimental research on influence of different unloading stress paths on permeability evolution for sandstone[J]. Chinese Journal of Rock Mechanics and Engineering，2018，37(11)：697–701.(in Chinese))
[5]	于洪丹，陈飞飞，陈卫忠，等. 含裂隙岩石渗流力学特性研究[J]. 岩石力学与工程学报，2012，31(增1)：2 788–2 795.(YU Hongdan，CHEN Feifei，CHEN Weizhong，et al. Research on permeability of fractured rock[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(Supp.1)：2 788–2 795.(in Chinese))
[13]	邓华锋，王哲，李建林，等. 卸荷速率和孔隙水压力对砂岩卸荷特性影响研究[J]. 岩土工程学报，2017，39(11)：1 976–1 983. (DENG Huafeng，WANG Zhe，LI Jianlin，et al. Effect of unloading rate and pore water pressure on mechanical properties of sandstone[J]. Chinese Journal of Geotechnical Engineering，2017，39(11)：1 976– 1 983.(in Chinese))
[15]	李志敬，朱珍德，施毅，等. 高围压高水压条件下岩石卸荷强度特性试验研究[J]. 河海大学学报：自然科学版，2009，37(2)：162–165.(LI Zhijing，ZHU Zhende，SHI Yi，et al. Unloading strength properties of rocks under high confining pressure and hydraulic pressure[J]. Journal of Hohai University：Natural Sciences，2009，37(2)：162–165.(in Chinese))
[4]	张东明，郑彬彬，尹光志，等. 采动应力下急倾斜煤层顶板砂岩的力学及渗透特性[J]. 煤炭学报，2017，42(增1)：128–137.(ZHANG Dongming，ZHENG Binbin，YIN Guangzhi，et al. Mechanics and permeability characteristics of steep seam roof sandstone under disturbance stress[J]. Journal of China Coal Society，2017，42(Supp.1)：128–137.(in Chinese))
[7]	梁宁慧，刘新荣，艾万民，等. 裂隙岩体卸荷渗透规律试验研究[J]. 土木工程学报，2011，44(1)：88–92.(LIANG Ninghui，LIU Xinrong，AI Wanmin，et al. Experiment study on the permeability of fractured rock under unloading[J]. China Civil Engineering Journal，2011，44(1)：88–92.(in Chinese))
[10]	刘新荣，刘俊，冯昊，等. 不同初始卸荷水平和水压下砂岩卸荷力学特性试验研究[J]. 岩土工程学报，2018，40(6)：1 143–1 151. (LIU Xinrong，LIU Jun，FENG Hao，et al. Experimental research on unloading mechanical properties of sandstone under different initial unloading levels and pore pressures[J]. Chinese Journal of Geotechnical Engineering，2018，40(6)：1 143–1 151.(in Chinese))
[12]	张向东，李亦芃，李庆文，等. 考虑流固耦合效应深埋富水隧道围岩稳定性研究[J]. 长江科学院学报，2018，35(10)：98–103. (ZHANG Xiangdong，LI Yifan，LI Qingwen，et al. Surrounding rock stability of deep buried water-rich tunnel in consideration of fluid-solid coupling[J]. Journal of Yangtze River Scientific Research Institute，2018，35(10)：98–103.(in Chinese))
[14]	邓华锋，王哲，李建林，等. 低孔隙水压力对砂岩卸荷力学特性影响研究[J]. 岩石力学与工程学报，2017，36(增1)：3 266–3 275. (DENG Huafeng，WANG Zhe，LI Jianlin，et al. Experimental research about influence of low pore water pressure on unloading mechanical properties of sandstone[J]. Journal of Rock Mechanics and Engineering，2017，36(Supp.1)：3 266–3 275.(in Chinese))
[17]	WANG K W，LI N. Numerical simulation of rock pore-throat structure effects on NUM T2 distribution[J]. Applied Geophysics，2008，5(2)：86–91.
[20]	周科平，胡振襄，李杰林，等. 基于核磁共振技术的大理岩卸荷损伤演化规律研究[J]. 岩石力学与工程学报，2014，33(增2)：3 523– 3 530.(ZHOU Keping，HU Zhenxiang，LI Jielin，et al. Study of marble damage evolution laws under unloading conditions based on nuclear magnetic resonance technique[J]. Chinese Journal of Rock Mechanics and Engineering，2014，33(Supp.2)：3 523–3 530.(in Chinese))