|
|
|
| Study on creep mechanical properties of frozen cretaceous sandstone during thawing process |
| LI Zuyong1,YANG Gengshe1,WEI Yao2 |
(1. College of Architecture and Civil Engineering,Xi'an University of Science and Technology,Xi'an,Shaanxi 710054,China;
2. State Key Laboratory of Road Engineering Safety and Health in Cold and High-altitude Regions,CCCC First Highway Consultants Co.,Ltd.,Xi¢an,Shaanxi 710065,China)
|
|
|
|
|
Abstract After construction,shaft freezing walls will experience a long thawing process,creep deformation will occur under long-term loads. The creep behavior of frozen rocks during the thawing process is the key issue to control the long-term stability of the frozen walls. Based on the freezing engineering of the return air shaft in Xinzhuang Coal Mine,Gansu,this paper analyzes the creep mechanical characteristics of the frozen Cretaceous sandstone during the thawing process. At the same time,nuclear magnetic resonance technology is used to test the change of the pore water content during the thawing process to analyze the relationship between the unfrozen water and the sandstone strength. Based on the fractional order theory,a nonlinear creep constitutive equation is established. The results show that the pore water in rocks mainly presents three forms such as free water,capillary water and adsorbed water,mainly exists in the forms of free water at room temperature and adsorbed water at low temperature. During the thawing process of frozen sandstone,the long-term strength,gradually decreasing with increasing temperature,is about 45%–51% of the conventional triaxial compressive strength,and changes suddenly at – 4 ℃. It is also found that the long-term strength of the frozen sandstone is closely related to the unfrozen water content,showing an exponential function. The creep failure of the frozen sandstone is mainly due to the coupling of stress field,chemical potential field and seepage field,and the stress field plays a leading role. According to the creep deformation characteristics of the frozen sandstone during the thawing process,and introducing a fractional order function,a corresponding nonlinear creep equation is established based on the fractional order theory. The research results can provide theoretical and technical support for evaluating the instability and damage of frozen walls induced by the thawing.
|
|
|
|
|
|
[1] 杨更社,屈永龙,奚家米,等. 西部白垩系富水基岩立井冻结压力实测研究[J]. 采矿与安全工程学报,2014,31(6):982–986.(YANG Gengshe,QU Yonglong,XI Jiami,et al. In-situ measurement and study of freezing pressure of shaft in western cretaceous water-rich bedrock[J]. Journal of Mining and Safety Engineering,2014,31(6):982–986.(in Chinese))
[2] 杨更社,屈永龙,奚家米. 白垩系地层煤矿立井冻结壁的力学特性及温度场研究[J]. 岩石力学与工程学报,2014,33(9):1 873–1 879. (YANG Gengshe,QU Yonglong,XI Jiami. Study of mechanical properties and temperature field of frozen wall in cretaceous strata[J]. Chinese Journal of Rock Mechanics and Engineering,2014,33(9):1 873–1 879.(in Chinese))
[3] 张 驰. 基岩冻结新型单层井壁现浇混凝土温度场实测研究[J]. 采矿与安全工程学报,2017,34(4):769–774.(ZHANG Chi. Measurement of cast-in-situ concrete temperature field of a new single-layer shaft lining in bed rock during freezing sinking[J]. Journal of Mining and Safety Engineering,2017,34(4):769–774.(in Chinese))
[4] 刘 波,马永君,盛海龙,等. 不同围压与冻结温度下白垩系红砂岩力学性质试验研究[J]. 岩石力学与工程学报,2019,38(3):455–466.(LIU Bo,MA Yongjun,SHENG Hailong,et al. Experimental study on mechanical properties of Cretaceous red sandstone under different freezing temperatures and confining pressures[J]. Chinese Journal of Rock Mechanics and Engineering,2019,38(3):455–466.(in Chinese))
[5] 刘 波,孙颜顶,袁艺峰,等. 不同含水率冻结砂岩强度特性及强度强化机制[J]. 中国矿业大学学报,2020,49(6):1 085–1 093.(LIU Bo,SUN Yanding,YUAN Yifeng,et al. Strength characteristics of frozen sandstone with different water content and its strengthening mechanism[J]. Journal of China University of Mining and Technology,2020,49(6):1 085–1 093.(in Chinese))
[6] 杨 阳,李祥龙,杨仁树,等. 低温岩石冲击破碎分形特征与断口形貌分析[J]. 北京理工大学学报,2020,40(6):632–639.(YANG Yang,LI Xianglong,YANG Renshu,et al. Study on fractal characteristics and fracture mechanism of frozen rocks[J]. Transactions of Beijing Institute of Technology,2020,40(6):632–639.(in Chinese))
[7] 杨 阳,杨仁树. 高应变率下红砂岩“冻伤效应”[J]. 工程科学学报,2019,41(10):1 249–1 257.(YANG Yang,YANG Renshu. “Frostbite effect” of red sandstone under high strain rates[J]. Chinese Journal of Engineering,2019,41(10):1 249–1 257.(in Chinese))
[8] 杨更社,魏 尧,申艳军,等. 冻结饱和砂岩三轴压缩力学特性及强度预测模型研究[J]. 岩石力学与工程学报,2019,38(4):683–694.(YANG Gengshe,WEI Yao,SHEN Yanjun,et al. Mechanical behavior and strength forecast model of frozen saturated sandstone under triaxial compression[J]. Chinese Journal of Rock Mechanics and Engineering,2019,38(4):683–694.(in Chinese))
[9] 杨更社,申艳军,贾海梁,等. 冻融环境下岩体损伤力学特性多尺度研究及进展[J]. 岩石力学与工程学报,2018,37(3):545–563.(YANG Gengshe,SHEN Yanjun,JIA Hailiang,et al. Research progress and tendency in characteristics of multi-scale damage mechanics of rock under freezing-thawing[J]. Chinese Journal of Rock Mechanics and Engineering,2018,37(3):545–563.(in Chinese))
[10] 董西好,杨更社,田俊峰,等. 侧向卸荷条件下冻结砂岩变形特性[J]. 岩土力学,2018,39(7):2 518–2 526.(DONG Xihao,YANG Gengshe,TIAN Junfeng,et al. Characteristics of deformation properties of frozen sandstone under lateral unloading condition[J]. Rock and Soil Mechanics,2018,39(7):2 518–2 526.(in Chinese))
[11] 刘 慧,杨更社,叶万军,等. 基于CT图像三值分割的冻结岩石水冰含量及损伤特性分析[J]. 采矿与安全工程学报,2016,33(6):1 130–1 137.(LIU Hui,YANG Gengshe,YE Wanjun,et al. Analysis of water and ice content and damage characteristics of the frozen rock during freezing based on the three-valued segmentation of CT images[J]. Journal of Mining and Safety Engineering,2016,33(6):1 130–1 137.(in Chinese))
[12] TOMANOVIC Z,MILADINOVIC B,ZIVALJEVIC S,et al. Criteria for defining the required duration of a creep test[J]. Canadian Geotechnical Journal,2015,52(7):883–889.
[13] HASHIBA K,FUKUI K. Twenty-year creep test with tuff under uniaxial compression[J]. Geotechnical Testing Journal,2020,43(3):800–808.
[14] 王 宇,艾 芊,李建林,等. 考虑不同影响因素的砂岩损伤特征及其卸荷破坏细观特性研究[J]. 岩土力学,2019,40(4):1 341– 1 350.(WANG Yu,AI Qian,LI Jianlin,et al. Damage characteristics of sandstone under different influence factors and its unloading failure meso-morphology properties[J]. Rock and Soil Mechanics,2019,40(4):1 341–1 350.(in Chinese))
[15] 张强勇,张龙云,向 文,等. 考虑温度效应的片麻状花岗岩三轴蠕变试验研究[J]. 岩土力学,2017,38(9):2 507–2 514.(ZHANG Qiangyong,ZHANG Longyun,XIANG Wen,et al. Triaxial creep test of gneissic granite considering thermal effect[J]. Rock and Soil Mechanics,2017,38(9):2 507–2 514.(in Chinese))
[16] 王青元,刘 杰,王培涛,等. 冲击扰动诱发蠕变岩石加速失稳破坏试验[J]. 岩土力学,2020,41(3):781–788 (WANG Qingyuan,LIU Jie,WANG Peitao,et al. Experimental investigation of accelerated failure of creep rock induced by impact disturbance[J]. Rock and Soil Mechanics,2020,41(3):781–788.(in Chinese))
[17] 苏荣华,刘晓林,沈洪爽. 周期冲击扰动下粉砂岩单轴蠕变特性研究[J]. 应用基础与工程科学学报,2018,26(6):1 327–1 337.(SU Ronghua,LIU Xiaolin,SHEN Hongshuang. Uniaxial creep characteristics of siltstone under cyclic shock disturbance[J]. Journal of Basic Science and Engineering,2018,26(6):1 327–1 337.(in Chinese))
[18] 单仁亮,白 瑶,孙鹏飞,等. 冻结层状红砂岩三轴蠕变特性及本构模型研究[J]. 中国矿业大学学报,2019,48(1):12–22.(SHAN Renliang,BAI Yao,SUN Pengfei,et al. Study of triaxial creep mechanical properties and constitutive model of frozen stratified red sandstone[J]. Journal of China University of Mining and Technology,2019,48(1):12–22.(in Chinese))
[19] 魏 尧,杨更社,申艳军,等. 白垩系饱和冻结砂岩蠕变试验及本构模型研究[J]. 岩土力学,2020,41(8):2 636–2 646.(WEI Yao,YANG Gengshe,SHEN Yanjun,et al. Creep test and constitutive model of cretaceous saturated frozen sandstone[J]. Rock and Soil Mechanics,2020,41(8):2 636–2 646.(in Chinese))
[20] LI Z Y,YANG G S,WEI Y. Construction of frozen sandstone creep damage model and analysis of influencing factors based on fractional-order theory[J]. Arabian Journal for Science and Engineering,2021.
[21] 宋勇军,张磊涛,任建喜,等. 低温环境下红砂岩蠕变特性及其模型[J]. 煤炭学报,2020,45(8):2 795–2 803.(SONG Yongjun,ZHANG Leitao,REN Jianxi,et al. Creep property and model of red sandstone under low temperature environment[J]. Journal of China Coal Society,2020,45(8):2 795–2 803.(in Chinese))
[22] COATES G R,MARSCHALL D,MARDON D,et al. A new characterization of bulk-volume irreducible using magnetic resonance[J]. Log Analyst,1997,39(1):51–63.
[23] ZHAO Y X,SUN Y F,LIU S M,et al. Pore structure characterization of coal by NMR cryoporometry[J]. Fuel,2017,190:359–369.
[24] 王青元,朱万成,刘洪磊,等. 单轴压缩下绿砂岩长期强度的尺寸效应研究[J]. 岩土力学,2016,37(4):981–990.(WANG Qingyuan,ZHU Wancheng,LIU Honglei,et al. Size effect of long-term strength of sandstone under uniaxial compression[J]. Rock and Soil Mechanics,2016,37(4):981–990.(in Chinese))
[25] 王 振,沈明荣,顾琳琳. 以等应变速率曲线为基础的岩石长期强度确定方法[J]. 哈尔滨工业大学学报,2017,49(6):77–83.(WANG Zhen,SHEN Mingrong,GU Linlin. Methods for determining long-term strength of rock based on iso-strain rate creep curves[J]. Journal of Harbin Institute of Technology,2017,49(6):77–83.(in Chinese))
[26] 张 玉,金培杰,徐卫亚,等. 坝基碎屑岩三轴蠕变特性及长期强度试验研究[J]. 岩土力学,2016,37(5):1 291–1 300.(ZHANG Yu,JIN Peijie,XU Weiya,et al. Experimental study of triaxial creep behavior and long-term strength of clastic rock in dam foundation[J]. Rock and Soil Mechanics,2016,37(5):1 291–1 300.(in Chinese))
[27] WU F,GAO R,ZOU Q,et al. Long-term strength determination and nonlinear creep damage constitutive model of salt rock based on multistage creep test:Implications for underground natural gas storage in salt caver[J]. Energy Science and Engineering,2020,8(5),1 592–1 603. |
|
|
|