岩石疲劳损伤及破坏前兆研究现状与展望

刘新锋; 赵英群; 王晓睿; 于怀昌

doi:10.3799/dqkx.2021.186

岩石疲劳损伤及破坏前兆研究现状与展望

doi: 10.3799/dqkx.2021.186

刘新锋^{1, 2,},
赵英群³,
王晓睿²,
于怀昌^2, ,

1.
河南交投平宛高速公路有限公司, 河南郑州 450045
2.
华北水利水电大学地球科学与工程学院, 河南郑州 450045
3.
郑州地铁集团, 河南郑州 450000

基金项目:

国家自然科学基金青年项目 51309100

详细信息

作者简介:
刘新锋（1966-），男，高级工程师，主要从事环境地质灾害评价和高速公路建设管理及研究工作.E-mail：1353272186@qq.com

通讯作者:
于怀昌, 教授, 博士，主要从事岩石力学及工程、城市地下空间结构等方面研究工作，E-mail：yuhuaichang@ncwu.edu.cn

中图分类号: P642
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出版历程
- 收稿日期: 2021-08-10
- 刊出日期: 2022-06-25

Current Status and Prospects of Research on Fatigue Damage and Failure Precursors of Rocks

1.
Henan Jiaotou Pingwan Expressway Co., Ltd., Zhengzhou 450045, China
2.
College of Geoscience and Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450045, China
3.
Zhengzhou Metro Group, Zhengzhou 450000, China

摘要

摘要: 疲劳是岩石的重要力学特性之一，与工程的安全稳定密切相关.在循环荷载作用下，岩石初始损伤不断累积、加剧，最终导致岩石的失稳破坏，从而诱发工程灾变.阐述了近年来基于声发射、红外辐射技术开展岩石疲劳损伤与破坏方面的研究进展.首先论述了研究人员采用声发射时域参数、声发射空间演化以及Felicity比开展岩石疲劳损伤特性的研究进展.进而，针对研究人员采用声发射时域参数、损伤变量、分形维值、Felicity比、加卸载响应比、RA以及b值等参数开展岩石疲劳破坏前兆的研究进展进行讨论.在此基础上，论述了研究人员采用红外辐射技术开展岩石疲劳损伤与破坏前兆的研究进展.最后，提出了今后岩石疲劳损伤与破坏前兆研究中需要进一步深入解决的几点问题.本文可对深入认识岩石疲劳损伤机理、破坏前兆特征起到积极的促进作用.
- 疲劳损伤 /
- 破坏 /
- 声发射 /
- 红外辐射 /
- 岩土工程 /
- 工程地质
Abstract: Fatigue is one of the important mechanical properties of rocks, which is closely related to the safety and stability of engineering. Under the action of circulating loads, the initial damage of the rock continues to accumulate and intensify, eventually leading to the instability and destruction of the rock, thus inducing engineering catastrophes. In this paper, it describes the research progress of rock fatigue damage and failure based on acoustic emission and infrared radiation technology in recent years. Firstly, it discusses the research progress of rock fatigue damage characteristics carried out by researchers using acoustic emission time-domain parameters, acoustic emission spatial evolution, and Felicity ratio. Then, it discusses the research progress of researchers using acoustic emission time-domain parameters, damage variables, fractal dimension values, Felicity ratio, loading/unloading response ratio, RA and b-value parameters to carry out the research progress of rock fatigue failure precursors. On this basis, it also discusses the research progress of researchers using infrared radiation technology to develop rock fatigue damage and failure precursors.Finally, several issues that need to be further resolved in the future research on rock fatigue damage and failure precursors are put forward. This article can play a positive role in promoting the in-depth understanding of rock fatigue damage mechanism and failure precursor characteristics.
- fatigue damage /
- failure /
- acoustic emission /
- infrared radiation /
- geotechnical engineering /
- engineering geology

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参考文献(77)

Akdag, S., Karakus, M., Taheri, A., et al., 2018. Effects of Thermal Damage on Strain Burst Mechanism for Brittle Rocks under True-Triaxial Loading Conditions. Rock Mechanics and Rock Engineering, 51(6): 1657-1682. https://doi.org/10.1007/s00603-018-1415-3
Cao, K. W., Ma, L. Q., Wu, Y., et al., 2021. Cyclic Fatigue Characteristics of Rock Failure Using Infrared Radiation as Precursor to Violent Failure: Experimental Insights from Loading and Unloading Response. Fatigue & Fracture of Engineering Materials & Structures, 44(2): 584-594. https://doi.org/10.1111/ffe.13362
Chen, Y. L., Zhang, Y., 2018. Influence of Loading Rate on the Kaiser Effect for Different Lithological Rocks. Journal of China Coal Society, 43(4): 959-966(in Chinese with English abstract).
Feng, X. T., Gao, Y. H., Zhang, X. W., et al., 2020. Evolution of the Mechanical and Strength Parameters of Hard Rocks in the True Triaxial Cyclic Loading and Unloading Tests. International Journal of Rock Mechanics and Mining Sciences, 131: 104349. https://doi.org/10.1016/j.ijrmms.2020.104349
Guo, J., Feng, G. R., Qi, T. Y., et al., 2018. Dynamic Mechanical Behavior of Dry and Water Saturated Igneous Rock with Acoustic Emission Monitoring. Shock and Vibration, 2018: 1-14. https://doi.org/10.1155/2018/2348394
He, J., Pan, J. N., Wang, A. H., 2014. Acoustic Emission Characteristics of Coal Specimen under Triaxial Cyclic Loading and Unloading. Journal of China Coal Society, 39(1): 84-90(in Chinese with English abstract).
He, M. C., Ren, F. Q., Gong, W. L., et al., 2017. Temperature Characteristics during Physical Simulation Test of Strain Burst. Journal of China University of Mining & Technology, 46(4): 692-698(in Chinese with English abstract).
Huo, M. Z., Xia, Y. Y., Liu, X. Q., et al., 2020. Evolution Characteristics of Temperature Fields of Rockburst Samples under Different Stress Gradients. Infrared Physics & Technology, 109: 103425. https://doi.org/10.1016/j.infrared.2020.103425
Jiang, D. Y., Xie, K. N., Chen, J., et al., 2019. Experimental Analysis of Sandstone under Uniaxial Cyclic Loading through Acoustic Emission Statistics. Pure and Applied Geophysics, 176(1): 265-277. https://doi.org/10.1007/s00024-018-1960-4
Kang, J. T., Wu, Q., Tang, H. M., et al., 2019. Strength Degradation Mechanism of Soft and Hard Interbedded Rock Masses of Badong Formation Caused by Rock/Discontinuity Degradation. Earth Science, 44(11): 3950-3960(in Chinese with English abstract).
Li, C. M., Liu, N., Liu, W. R., et al., 2021. Study on Characteristics of Energy Storage and Acoustic Emission of Rock under Different Moisture Content. Sustainability, 13(3): 1041. https://doi.org/10.3390/su13031041
Li, D. X., Wang, E. Y., Kong, X. G., et al., 2019. Damage Precursor of Construction Rocks under Uniaxial Cyclic Loading Tests Analyzed by Acoustic Emission. Construction and Building Materials, 206: 169-178. https://doi.org/10.1016/j.conbuildmat.2019.02.074
Li, H. R., Yang, C. H., Li, B. L., et al., 2016. Damage Evolution and Characteristics of Ultrasonic Velocity and Acoustic Emission for Salt Rock under Triaxial Multilevel Loading Test. Chinese Journal of Rock Mechanics and Engineering, 35(4): 682-691(in Chinese with English abstract).
Li, S. L., Tang, H. Y., 2010. Acoustic Emission Characteristics in Failure Process of Rock under Different Uniaxial Compressive Loads. Chinese Journal of Geotechnical Engineering, 32(1): 147-152(in Chinese with English abstract).
Li, S. L., Zhou, M. J., Gao, Z. P., et al., 2019. Experimental Study on Acoustic Emission Characteristics before the Peak Strength of Rocks under Incrementally Cyclic Loading-Unloading Methods. Chinese Journal of Rock Mechanics and Engineering, 38(4): 724-735(in Chinese with English abstract).
Li, X. J., He, P. J., Tang, J. H., et al., 2021. Experimental and Numerical Studies on Fracture Characteristics of Notched Granite Beams under Cyclic Loading and Unloading. The Journal of Strain Analysis for Engineering Design, 56(1): 3-17. doi: 10.1177/0309324720923218
Li, Z. C., Liu, J. F., Deng, C. F., et al., 2018. Experimental Study on Deformation and Failure Characteristics of Salt Rock Three-Point-Bending Samples with Impurities. Chinese Journal of Geotechnical Engineering, 40(Suppl. 2): 101-106(in Chinese with English abstract).
Liang, D. X., Zhang, N., Xie, L. X., et al., 2019. Damage and Fractal Evolution Trends of Sandstones under Constant-Amplitude and Tiered Cyclic Loading and Unloading Based on Acoustic Emission. International Journal of Distributed Sensor Networks, 15(7): 155014771986102. https://doi.org/10.1177/1550147719861020
Liu, J. F., Ding, G. S., Zhang, Q. X., et al., 2020. Investigation on Fracture Mechanical Behavior of Salt Rock with Impurities under Bending Loading-Unloading Conditions. Advanced Engineering Sciences, 52(3): 107-114(in Chinese with English abstract).
Meng, H. J., Wang, Y., Zhang, B., et al., 2020. Investigation on the Effect of Dynamic Frequency on Fracture Evolution in Preflawed Rock under Multistage Cyclic Loads: Insight from Acoustic Emission Monitoring. Geofluids, 2020: 8891395. https://doi.org/10.1155/2020/8891395
Meng, Q. B., Zhang, M. W., Han, L. J., et al., 2018. Acoustic Emission Characteristics of Red Sandstone Specimens under Uniaxial Cyclic Loading and Unloading Compression. Rock Mechanics and Rock Engineering, 51(4): 969-988. https://doi.org/10.1007/s00603-017-1389-6
Nejati, H. R., Ghazvinian, A., 2014. Brittleness Effect on Rock Fatigue Damage Evolution. Rock Mechanics and Rock Engineering, 47(5): 1839-1848. https://doi.org/10.1007/s00603-013-0486-4
Pei, F., 2020. Analysis and Control of Mechanical Properties and Surrounding Rock Stability of Deep Strata in Siling Gold Mine (Dissertation). University of Science and Technology Beijing, Beijing(in Chinese with English abstract).
Pei, F., Ji, H. G., Zhao, J. W., et al., 2020. Energy Evolution and AE Failure Precursory Characteristics of Rocks with Different Rockburst Proneness. Advances in Civil Engineering, (9): 8877901. https://doi.org/10.1155/2020/8877901
Ren, F. Q., Zhu, C., He, M. C., 2020. Moment Tensor Analysis of Acoustic Emissions for Cracking Mechanisms during Schist Strain Burst. Rock Mechanics and Rock Engineering, 53(1): 153-170. https://doi.org/10.1007/s00603-019-01897-3
Ren, S., Bai, Y. M., Jiang, D. Y., et al., 2012. Experimental Research on Acoustic Emission Property of Salt Rock under Cyclic Loading. Rock and Soil Mechanics, 33(6): 1613-1618, 1639(in Chinese with English abstract).
Sheinin, V. I., Blokhin, D. I., Maksimovich, I. B., et al., 2016. Experimental Research into Thermomechanical Effects at Linear and Nonlinear Deformation Stages in Rock Salt Specimens under Cyclic Loading. Journal of Mining Science, 52(6): 1039-1046. https://doi.org/10.1134/s1062739116061575
Shen, R. X., Chen, T. Q., Li, T. X., et al., 2020. Study on the Effect of the Lower Limit of Cyclic Stress on the Mechanical Properties and Acoustic Emission of Sandstone under Cyclic Loading and Unloading. Theoretical and Applied Fracture Mechanics, 108: 102661. https://doi.org/10.1016/j.tafmec.2020.102661
Tang, J. H., Chen, X. D., Dai, F., et al., 2020. Experimental Investigation of Fracture Damage of Notched Granite Beams under Cyclic Loading Using DIC and AE Techniques. Fatigue & Fracture of Engineering Materials & Structures, 43(7): 1583-1596. https://doi.org/10.1111/ffe.13253
Wang, J. F., Yuan. W., He. K., et al., 2020. Influence of Stress History on Consolidation Coefficient of Saturated Soft Soil. Earth Science, 45(12): 4640-4648(in Chinese with English abstract).
Wang, K., Li, X., Huang, Z., et al., 2021a. Experimental Study on Acoustic Emission and Resistivity Response of Sandstone under Constant Amplitude Cyclic Loading. Advances in Materials Science and Engineering, 2021: 6637200. https://doi.org/10.1155/2021/6637200
Wang, T. Z., Wang, C. L., Xue, F., et al., 2021b. Acoustic Emission Characteristics and Energy Evolution of Red Sandstone Samples under Cyclic Loading and Unloading. Shock and Vibration, (2): 8849137. https://doi.org/10.1155/2021/8849137
Wang, X. R., Cai, S., Yang, W., et al., 2022. Influence of Existing Buildings on Construction of Earth Pressure Shield in Extremely Soft Rock Stratum. Earth Science, 47(4): 1483-1491(in Chinese with English abstract).
Wang, Y., Gao, S. H., Meng, H. J., et al., 2021. Investigation on Acoustic Emission Characteristics and Fracture Network Patterns of Pre-Flawed Granite Subjected to Increasing-Amplitude Fatigue Loads. Chinese Journal of Rock Mechanics and Engineering, 40(10): 1976-1989(in Chinese with English abstract).
Wang, Y., Meng, H. J., Long, D. Y., 2021d. Experimental Investigation of Fatigue Crack Propagation in Interbedded Marble under Multilevel Cyclic Uniaxial Compressive Loads. Fatigue & Fracture of Engineering Materials & Structures, 44(4): 933-951. https://doi.org/10.1111/ffe.13404
Wang, Y., Zhang, B., Gao, S. H., et al., 2021c. Investigation on the Effect of Freeze-Thaw on Fracture Mode Classification in Marble Subjected to Multi-Level Cyclic Loads. Theoretical and Applied Fracture Mechanics, 111(6): 102847. https://doi.org/10.1016/j.tafmec.2020.102847
Wen, T., Tang, H. M., Ma, J. W., et al., 2019. Deformation Simulation for Rock in Consideration of Initial Damage and Residual Strength. Earth Science, 44(2): 652-663(in Chinese with English abstract).
Xiao, F. K., Liu, G., Shen, Z. L., et al., 2016. Energy Conversion and Acoustic Emission (AE) Characteristics of Coal Samples under Cyclic Loading. Chinese Journal of Rock Mechanics and Engineering, 35(10): 1954-1964(in Chinese with English abstract).
Xu, J., Li, S. C., Tang, X. J., et al., 2009. Rock Fatigue Damage Evolution Based on Acoustic Emission. Journal of University of Science and Technology Beijing, 31(1): 19-24(in Chinese with English abstract).
Xu, J., Tang, X. J., Li, S. C., et al., 2008. Space-Time Evolution Rules Study of Acoustic Emission Locations in Rock under Cyclic Loading. Journal of Chongqing University, 31(6): 672-676(in Chinese with English abstract).
Yang, J. M., 2020. Experimental Study on Acoustic Emission Signal Characteristics during Limestone Loading. Anhui Architecture, 27(6): 167-169(in Chinese with English abstract).
Yang, S. Q., Huang, Y. H., Tang, J. Z., 2020. Mechanical, Acoustic, and Fracture Behaviors of Yellow Sandstone Specimens under Triaxial Monotonic and Cyclic Loading. International Journal of Rock Mechanics and Mining Sciences, 130(7): 104268. https://doi.org/10.1016/j.ijrmms.2020.104268
Yang, X. B., Han, X. X., Liu, E. L., et al., 2018. Experimental Study on the Acoustic Emission Characteristics of Non-Uniform Deformation Evolution of Granite under Cyclic Loading and Unloading Test. Rock and Soil Mechanics, 39(8): 2732-2739(in Chinese with English abstract).
Yang, Y. J., Xing, L. Y., 2020. Experimental Research on Acoustic Emission Characteristics and Felicity Effects during Coal Fatigue Failure under Cyclic Loading. Advances in Materials Science and Engineering, (10): 3453128. https://doi.org/10.1155/2020/3453128
Zhang, M. B., Cui, L., Hu, W. J., et al., 2020. Acoustic Emission Experimental Research of the Damage Characteristics of Raw Coal under Different Loading and Unloading Rates. Shock and Vibration, (2020): 9063929. https://doi.org/10.1155/2020/9063929
Zhang, X., Zhou, Z. H., Zhang, J. Y., et al., 2020. Research on Acoustic Emission Precursors of Instability of Marble under Uniaxial Cyclic Loading and Unloading Conditions. Industrial Minerals & Processing, 49(6): 1-6(in Chinese with English abstract).
Zhao, G. M., Wang, C., Liang, D. X., 2018. Comparative Experimental Studies of Acoustic Emission Characteristics of Sandstone and Mudstone under the Impacts of Cyclic Loading and Unloading. International Journal of Distributed Sensor Networks, 14(8): 155014771879555. https://doi.org/10.1177/1550147718795552
Zhao, X. D., Li, Y. H., Yuan, R. F., et al., 2007. Experimental Verification/Analysis of Kaiser Effect in Granite. Journal of Northeastern University (Natural Science), 28(2): 254-257(in Chinese with English abstract).
Zhao, X. G., Li, P. F., Ma, L. K., et al., 2014. Damage and Dilation Characteristics of Deep Granite at Beishan under Cyclic Loading-Unloading Conditions. Chinese Journal of Rock Mechanics and Engineering, 33(9): 1740-1748(in Chinese with English abstract).
Zhao, Y. C., Yang, T. H., Xu, T., et al., 2018. Mechanical and Energy Release Characteristics of Different Water-Bearing Sandstones under Uniaxial Compression. International Journal of Damage Mechanics, 27(5): 640-656. https://doi.org/10.1177/1056789517697472
Zhao, Y. X., Gong, S., Teng, T., et al., 2018. Characteristics of the Load/Unload Response Ratio of Raw Coal under Uniaxial Multi-Level Cyclic Loading. Chinese Journal of Rock Mechanics and Engineering, 37(5): 1096-1105(in Chinese with English abstract).
Zhu, Y. B., Huang, X., Guo, J., et al., 2017. Experimental Study of Fatigue Characteristics of Gypsum Rock under Cyclic Loading. Chinese Journal of Rock Mechanics and Engineering, 36(4): 940-952(in Chinese with English abstract).
陈宇龙, 张玉, 2018. 加载速率对不同岩性岩石Kaiser效应影响. 煤炭学报, 43(4): 959-966. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201804008.htm
何俊, 潘结南, 王安虎, 2014. 三轴循环加卸载作用下煤样的声发射特征. 煤炭学报, 39(1): 84-90. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201401015.htm
何满潮, 任富强, 宫伟力, 等, 2017. 应变型岩爆物理模拟实验过程的温度特征. 中国矿业大学学报, 46(4): 692-698. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGKD201704002.htm
亢金涛, 吴琼, 唐辉明, 等, 2019. 岩石/结构面劣化导致巴东组软硬互层岩体强度劣化的作用机制. 地球科学, 44(11): 3950-3960. doi: 10.3799/dqkx.2019.110
李浩然, 杨春和, 李佰林, 等, 2016. 三轴多级荷载下盐岩声波声发射特征与损伤演化规律研究. 岩石力学与工程学报, 35(4): 682-691. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201604010.htm
李庶林, 唐海燕, 2010. 不同加载条件下岩石材料破裂过程的声发射特性研究. 岩土工程学报, 32(1): 147-152. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201001029.htm
李庶林, 周梦婧, 高真平, 等, 2019. 增量循环加卸载下岩石峰值强度前声发射特性试验研究. 岩石力学与工程学报, 38(4): 724-735. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201904007.htm
李志成, 刘建锋, 邓朝福, 等, 2018. 含杂质盐岩三点弯曲变形破坏特征试验研究. 岩土工程学报, 40(增刊2): 101-106. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2018S2023.htm
刘建锋, 丁国生, 张强星, 等, 2020. 弯曲加卸载下杂质盐岩断裂力学行为特征研究. 工程科学与技术, 52(3): 107-114. https://www.cnki.com.cn/Article/CJFDTOTAL-SCLH202003013.htm
裴峰, 2020. 纱岭金矿深部地层岩体力学性能与深竖井围岩稳定性分析及控制(博士论文). 北京: 北京科技大学.
任松, 白月明, 姜德义, 等, 2012. 周期荷载作用下盐岩声发射特征试验研究. 岩土力学, 33(6): 1613-1618, 1639. doi: 10.3969/j.issn.1000-7598.2012.06.003
王江锋, 袁威, 何况, 郑培信, 2020. 应力历史对饱和软土固结系数的影响. 地球科学, 45(12): 4640-4648. doi: 10.3799/dqkx.2020.184
王晓睿, 蔡松, 杨伟, 郑培信, 2022. 既有建筑对极软岩地层中土压盾构的施工影响. 地球科学, 47(4): 1483-1491. doi: 10.3799/dqkx.2020.326
王宇, 高少华, 孟华君, 等, 2021. 不同频率增幅疲劳荷载下双裂隙花岗岩破裂演化声发射特性与裂纹形态研究. 岩石力学与工程学报, 40(10): 1976-1989. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX202110003.htm
温韬, 唐辉明, 马俊伟, 等, 2019. 考虑初始损伤和残余强度的岩石变形过程模拟. 地球科学, 44(2): 652-663. doi: 10.3799/dqkx.2018.212
肖福坤, 刘刚, 申志亮, 等, 2016. 循环载荷作用下煤样能量转化规律和声发射变化特征. 岩石力学与工程学报, 35(10): 1954-1964. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201610002.htm
许江, 李树春, 唐晓军, 等, 2009. 基于声发射的岩石疲劳损伤演化. 北京科技大学学报, 31(1): 19-24. https://www.cnki.com.cn/Article/CJFDTOTAL-BJKD200901004.htm
许江, 唐晓军, 李树春, 等, 2008. 循环载荷作用下岩石声发射时空演化规律. 重庆大学学报(自然科学版), 31(6): 672-676. https://www.cnki.com.cn/Article/CJFDTOTAL-FIVE200806018.htm
杨建明, 2020. 石灰岩加载过程中声发射信号特征试验研究. 安徽建筑, 27(6): 167-169 https://www.cnki.com.cn/Article/CJFDTOTAL-AHJZ202006081.htm
杨小彬, 韩心星, 刘恩来, 等, 2018. 循环加卸载下花岗岩非均匀变形演化的声发射特征试验研究. 岩土力学, 39(8): 2732-2739. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201808003.htm
张鑫, 周宗红, 张俊杨, 等, 2020. 大理岩单轴循环加卸载失稳声发射先兆研究. 化工矿物与加工, 49(6): 1-6. https://www.cnki.com.cn/Article/CJFDTOTAL-HGKJ202006001.htm
赵兴东, 李元辉, 袁瑞甫, 等, 2007. 花岗岩Kaiser效应的实验验证与分析. 东北大学学报(自然科学版), 28(2): 254-257. https://www.cnki.com.cn/Article/CJFDTOTAL-DBDX200702025.htm
赵星光, 李鹏飞, 马利科, 等, 2014. 循环加、卸载条件下北山深部花岗岩损伤与扩容特性. 岩石力学与工程学报, 33(9): 1740-1748. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201409002.htm
赵毅鑫, 龚爽, 滕腾, 等, 2018. 单轴多级循环加载下原煤加卸载响应比演化特征. 岩石力学与工程学报, 37(5): 1096-1105. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201805004.htm
祝艳波, 黄兴, 郭杰, 等, 2017. 循环荷载作用下石膏质岩的疲劳特性试验研究. 岩石力学与工程学报, 36(4): 940-952. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201704018.htm