实时高温及加卸载作用下非饱和压实膨润土气渗与变形特性研究

doi:10.13722/j.cnki.jrme.2021.0287

摘要
图/表
参考文献
相关文章 (15)

全文: PDF (5148 KB) HTML (1 KB)
输出: BibTeX | EndNote (RIS)

摘要地下高放废物处置库多场耦合作用复杂，非饱和压实膨润土作为缓冲材料首选材料，需能够有效地将金属罐体表面产生的气体排出到外界以避免气压聚集。采用等效稳态法和应变片，测量样品在不同实时温度及围压加卸载作用下的体积变形和有效气体渗透率，分析变温及围压荷载对样品气渗与变形特性的影响。发现实时高温下，温度升高会增大样品加载时的压缩变形，而对卸载时的变形恢复影响不明显，且相同温度条件下加卸载过程中的有效气体渗透率与样品连通孔隙率之间均存在良好的指数关系。结合NMR扫描结果对升温降低样品气体渗透率的机制做出了解释：(1) 升温增大了样品的压缩变形，降低了连通孔隙率；(2) 升温加剧了气体分子的滑脱效应，增大了气流通过孔隙通道的阻力；(3) 孔隙水受热膨胀改变了其在样品中的分布，进一步压缩了连通孔隙的有效喉径。该试验结果和结论加深了对缓冲材料多物理场耦合作用机制的认识，为工程设计和数值模拟提供了数据支持。

	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
	魏天宇1
	2
	胡大伟1
	2
	周辉1
	2
	王旭宏3
	杨球玉3
	吕涛3
	侯伟3

关键词 ：土力学, 高放废物处置库, 缓冲材料, 实时温度, 气体渗透

Abstract：The multi-field coupling effect of underground high-level waste repository is complicated. As the first choice of buffer materials，unsaturated compacted bentonite needs to be able to effectively discharge the gas generated on the surface of the metal tank to the outside to avoid pressure accumulation. The quasi-stationary flow method and strain gauges are employed in this paper to measure the volume deformation and the effective gas permeability of two sets of unsaturated compacted bentonite samples under real-time temperature and confining pressure cycle. The influences of real-time temperature and stress cycle on the gas permeability and deformation characteristics of the samples are analyzed. Results suggest that the temperature increment will increase the compression deformation of the samples during loading，but has little effect on the deformation recovery during unloading. And there is a good exponential relationship between the effective gas permeability and the connected porosity of the samples during entire stress cycle under the same temperature condition. Combined with the NMR scan results，the mechanism of decline in gas permeability caused by temperature increasing is explained as：(1) the temperature rise increases the compression deformation of the samples and reduces the connected porosity，(2) the increase in temperature enhances the slippage effect of gas molecules and increases the resistance of air flow through pore channels，and (3) thermal expansion of pore water changes its distribution in the samples and further compresses the effective throat diameter of the connected pores. The present work deepens the understanding of the multi-physics coupling mechanism of buffer materials and provides data support for engineering design and numerical simulation.

Key words： soil mechanics high-level radioactive waste repository buffer materials real-time temperature gas permeability

引用本文:

魏天宇1，2，胡大伟1，2，周辉1，2，王旭宏3，杨球玉3，吕涛3，侯伟3. 实时高温及加卸载作用下非饱和压实膨润土气渗与变形特性研究[J]. 岩石力学与工程学报, 2022, 41(3): 587-595.
WEI Tianyu1，2，HU Dawei1，2，ZHOU Hui1，2，WANG Xuhong3，YANG Qiuyu3，LYU Tao3，HOU Wei3. Influences of real-time temperature and stress cycle on gas permeability and deformation characteristics of unsaturated compacted bentonite. , 2022, 41(3): 587-595.

链接本文:

http://rockmech.whrsm.ac.cn/CN/10.13722/j.cnki.jrme.2021.0287 或 http://rockmech.whrsm.ac.cn/CN/Y2022/V41/I3/587

[25]	KLINKENBERG L J. The permeability of porous media to liquids and gases[C]// Drilling and Production Practice. [S. l.]：American Petroleum Institute，1941：200-213.
[12]	XU L，YE W，YE B，et al. Investigation on gas migration in saturated materials with low permeability[J]. Engineering Geology，2015，197：94-102.
[3]	HALAYKO K S G. Gas flow in compacted clays[R]. Manitoba，Canada：University of Manitoba，1998.
[8]	GUO G，FALL M. Modelling of dilatancy-controlled gas flow in saturated bentonite with double porosity and double effective stress concepts[J]. Engineering Geology，2018，243：253-271.
[2]	LIU J F，DAVY C A，TALANDIER J，et al. Effect of gas pressure on the sealing efficiency of compacted bentonite-sand plugs[J]. Journal of Contaminant Hydrology，2014，170：10-27.
[5]	GRAHAM J，HALAYKO K G，HUME H，et al. A capillarity- advective model for gas break-through in clays[J]. Engineering Geology，2002，64(2/3)：273-286.
[7]	HARRINGTON J F，HORSEMAN S T. Gas migration in KBS-3 buffer bentonite. Sensitivity of test parameters to experimental boundary conditions[R]. Stockholm：Swedish Nuclear Fuel and Waste Management Co.，2003.
[10]	刘帅，王驹，刘晓东，等. 甘肃北山预选区地质处置系统初步FEPs分析[J]. 东华理工大学学报：自然科学版，2012，35(3)：256-262.(LIU Shuai，WANG Ju，LIU Xiaodong，et al. Preliminary FEPs analysis for high-level radioactive waste disposal system in Beishan，Gansu Province[J]. Journal of East China Institute of Technology：Natural Science，2012，35(3)：256-262.(in Chinese))
[15]	高玉峰，刘月妙，谢敬礼，等. 高放废物处置库缓冲材料气体渗透特性研究[J]. 中国矿业，2018，27(5)：158-163.(GAO Yufeng，LIU Yuemiao，XIE Jingli，et al. The gas permeability of buffer material for high-level radioactive waste disposal[J]. China Mining Magazine，2018，27(5)：158-163.(in Chinese))
[17]	LIU J，SKOCZYLAS F，TALANDIER J. Gas permeability of a compacted bentonite-sand mixture：coupled effects of water content，dry density，and confining pressure[J]. Canadian Geotechnical Journal，2015，52(8)：1 159-1 167.
[20]	叶为民，SCHANZ T，钱丽鑫，等. 高压实高庙子膨润土GMZ01的膨胀力特征[J]. 岩石力学与工程学报，2007，26(增2)：3 861-3 865. (YE Weimin，SCHANZ T，QIAN Lixin，et al. Characteristics of swelling pressure of densely compacted gaomiaozi bentonite GMZ01[J]. Chinese Journal of Rock Mechanics and Engineering，2007，26(Supp.2)：3 861-3 865.(in Chinese))
[18]	XU L，YE W M，CHEN Y G，et al. Investigation on gas permeability of compacted GMZ bentonite with consideration of variations in liquid saturation，dry density and confining pressure[J]. Journal of Contaminant Hydrology，2020，230：103622.
[28]	TODORUK T，LANGFORD C，KANTZAS A. Pore-scale redistribution of water during wetting of air-dried soils as studied by low-field NMR relaxometry[J]. Environmental Science and Technology，2003，37(12)：2 707-2 713.
[6]	HORSEMAN S T，HARRINGTON J F，SELLIN P. Gas migration in clay barriers[J]. Engineering Geology，1999，54(1/2)：139-149.
[16]	WEI T，HU D，ZHOU H，et al. Influences of degree of saturation and stress cycle on gas permeability of unsaturated compacted Gaomiaozi bentonite[J]. Engineering Geology，2019，254：54-62.
[26]	TIAN H，WEI C，et al. An NMR-Based analysis of soil-water characteristics[J]. Applied Magnetic Resonance，2014，45(1)：49-61.
[1]	ORTIZ L，VOLCKAERT G，MALLANTS D. Gas generation and migration in Boom clay，a potential host rock formation for nuclear waste storage[J]. Engineering Geology，2002，64(2/3)：287-296.
[4]	叶为民，刘樟荣，崔玉军. 高放废物地质处置库缓冲/回填材料的气体渗透问题研究进展[J]. 岩土工程学报，2018，40(6)：1 125- 1 134.(YE Weimin，LIU Zhangrong，CUI Yujun. Advances in gas permeation problems of buffer/backfill materials in high-level radioactive waste geological repository[J]. Chinese Journal of Geotechnical Engineering，2018，40(6)：1 125-1 134. (in Chinese))
[11]	YE W M，XU L，CHEN B，et al. An approach based on two-phase flow phenomenon for modeling gas migration in saturated compacted bentonite[J]. Engineering Geology，2014，169：124-132.
[13]	CUI Y. On the hydro-mechanical behaviour of MX80 bentonite-based materials[J]. Journal of Rock Mechanics and Geotechnical Engineering，2017，9(3)：565-574.
[14]	CUI Y J，TANG A M. On the chemo-thermo-hydro-mechanical behaviour of geological and engineered barriers[J]. Journal of Rock Mechanics and Geotechnical Engineering，2013，5(3)：169-178.
[21]	高玉峰，刘月妙，马利科，等. 压实膨润土砌块单轴压缩力学性能研究[J]. 世界核地质科学，2016，33(1)：50-54.(GAO Yufeng，LIU Yuemiao，MA Like，et al. Mechanical property of highly compacted bentonite blocks under uniaxial compression[J]. World Nuclear Geoscience，2016，33(1)：50-54.(in Chinese))
[23]	MEZIANI H，SKOCZYLAS F. An experimental study of the mechanical behaviour of a mortar and of its permeability under deviatoric loading[J]. Materials and Structures，1999，32：403-409.
[24]	DELAGE P，CUI Y J，LAURE E DE. Air flow through an unsaturated compacted silt[C]// Proceedings of the 2nd International Conference on Unsaturated Soils. Beijing：[s. n. ]，1998：563-568.
[9]	XU L，YE W M，CHEN Y G，et al. A new approach for determination of gas breakthrough in saturated materials with low permeability[J]. Engineering Geology，2018，241：121-131.
[19]	郑剑锋，马巍，赵淑萍，等. 重塑土室内制样技术对比研究[J]. 冰川冻土，2008，(3)：494-500.(ZHENG Jianfeng，MA Wei，ZHAO Shuping，et al. Development of the specimen-preparing technique for remoulded soil samples[J]. Journal of Glaciology and Geocryology，2008，(3)：494-500.(in Chinese))
[22]	刘月妙，蔡美峰，王驹，等. 高放废物地质处置库预选缓冲材料压缩性能研究[J]. 铀矿地质，2007，(2)：91-95.(LIU Yuemiao，CAI Meifeng，WANG Ju，et al. Compressibility of buffer material for HLW disposal in China[J]. Uranium Geology，2007，(2)：91-95.(in Chinese))
[27]	田慧会. 多相土中水分迁移与相变过程的核磁共振探测方法研究[博士学位论文][D]. 北京：中国科学院大学，2014.(TIAN Huihui. The study of NMR detection on water migration and phase change in multiphase soil[Ph. D. Thesis][D]. Beijing：University of Chinese Academy of Sciences，2014.(in Chinese))