Mechanical characteristics and failure mechanism of dry and wet shotcrete under loading

被引：0

作者：

Bai J. ^{[1
]}

Cheng Y. ^{[1
,2
]}

Zheng Q. ^{[1
,3
]}

Li F. ^{[1
]}

Li B. ^{[4
,5
]}

Wu F. ^{[4
,5
]}

机构：

[1] State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mine, Anhui University of Science and Technology, Huainan

[2] National Engineering Laboratory for Coal Mine Backfilling Mining, Shandong University of Science and Technology, Tai'an

[3] School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan

[4] State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing

[5] College of Resources and Environmental Sciences, Chongqing University, Chongqing

来源：

Meitan Xuebao/Journal of the China Coal Society | 2020年 / 45卷 / 08期

关键词：

Acoustic emission; Constitutive model; Damage variable; Dry shotcrete and wet spray shotcrete; Failure mechanism;

D O I：

10.13225/j.cnki.jccs.2019.0686

中图分类号：

学科分类号：

摘要：

At present, wet shotcrete is gradually replacing dry shotcrete, but the relevant supporting mechanism and design basis are lack of research.According to the mechanics tests of dry and wet shotcrete, the acoustic emission(AE) device is used to monitor the whole process of uniaxial compression, axial compression and Brazilian splitting instability in order to explore the mechanical properties and failure mechanism of wet sprayed concrete.The acoustic emission energy and impact number of the whole failure process of the sample, as well as the time and space characteristics of the failure point of the sample are obtained.Based on the test results, the failure mechanisms of dry and wet shotcrete are explored, and the uniaxial compressive strength, axial compressive strength and splitting tensile strength of dry and wet shotcrete at different ages are compared and analyzed.The relationships between the AE parameters of dry and wet shotcrete, such as stress, impact number, energy and strain are further studied.The relationship between damage variable and strain is quantitatively analyzed through the positioning results of AE specimens.The constitutive model of damage variable of dry and wet shotcrete is established.The results show that compared with dry shotcrete, the early and long-term mechanical properties of wet shotcrete are significantly improved, and the homogeneity is also significantly improved.Damage variable expressed by AE energy increases with the increase of strain, and cracks begin to penetrate gradually under specific strains.However, the growth rate of damage variable of wet shotcrete is slow before the peak strain is reached, and fast after the peak strain is reached.By comparing the experimental and computational curves of dry and wet shotcrete, it is shown that the constitutive model can be applied to the damage comparison of crack energy of dry and wet shotcrete. © 2020, Editorial Office of Journal of China Coal Society. All right reserved.

引用

页码：2777 / 2786

页数：9

共 27 条

[1] ALUN Thomas, Sprayed concrete lined tunnels, (2009)
[2] ZHU Guangbing, Progress of the research for shotcrete, Concrete, 4, pp. 105-109, (2011)
[3] REN Yu, CHENG Yunhai, WANG Guandong, Et al., Experimental analysis on mechanics properties and application of high stress roadway of wet shotcrete, Concrete, 3, pp. 128-130, (2013)
[4] DONG Zhaolu, Wet shotcrete technology research and application in qinan coal mine, (2016)
[5] REN Yu, Mechanical properties and engineering application of wet shotcrete in coal mine, (2014)
[6] TIAN Wei, DANG Faning, LIANG Xinyu, Et al., CT image analysis of meso-fracture process of concrete, Engineering Journal of Wuhan University, 41, 2, pp. 69-72, (2008)
[7] DENG Mingde, QIAN Jiadong, YIN Jingru, Et al., Research on the application of infrared remote sensing in the stability monitoring and unstability prediction of large concrete engineering, Chinese Journal of Rock Mechanic and Engineering, 20, 2, pp. 147-150, (2001)
[8] YU Qinglei, TANG Chun'an, ZHU Wancheng, Et al., Digital image-based numerical simulation on failure process of concrete, Engineering Mechanics, 25, 9, pp. 72-78, (2008)
[9] SCHIAVI A, NICCOLINI G, TARIZZO P, Et al., Acoustic emissions at high and low frequencies during compression tests in brittle materials, Strain, 47, S2, pp. 105-110, (2011)
[10] OHTSU M, UCHIDA M, OKAMOTO T, Et al., Damage assessment of rei-nforced concrete beams qualified by acoustic emission, Aci Structural Journal, 99, 4, pp. 411-417, (2002)

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