Investigation on fracture evolution of pre-flawed hollow-cylinder granite under increasing-amplitude cyclic loads

被引：0

作者：

Wang Y. ^{[1
,2
]}

Yang H. ^{[1
,2
]}

Yi X. ^{[1
,2
]}

Li J. ^{[1
,2
]}

Li C. ^{[1
,2
]}

机构：

[1] Beijing Key Laboratory of Urban Underground Space Engineering, University of Science and Technology Beijing, Beijing

[2] Key Laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mines, University of Science and Technology Beijing, Beijing

来源：

Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | 2022年 / 41卷 / 07期

基金：

中国国家自然科学基金;

关键词：

acoustic emission; CT scanning; fatigue failure; fracture evolution; hollow-cylinder granite; rock mechanics;

D O I：

10.13722/j.cnki.jrme.2021.0805

中图分类号：

学科分类号：

摘要：

This work aims to reveal the fracture evolution characteristics and the meso-mechanical mechanism of the pre-flawed hollow cylinder granite subjected to stress disturbance with a kind of medium-low strain rate, and to further investigate the fracture and instability process of the cavity-fissure composite rock mass commonly encountered in underground engineering. Typical four hollow cylinder specimens with different prefabricated flaw angles were tested using the CTS-RTR 2000 rock mechanics testing system, the real-time acoustic emission(AE) monitoring and the post-test computed tomography(CT) scanning technique. The experimental results show that: (1) The rock fatigue strength, the volume deformation and the fatigue life gradually increase with the flaw angle, and the growth rate of the volume deformation becomes faster. Using the irreversible axial strain, a two-stage damage evolution model was proposed to describe the fatigue damage of rock. (2) The AE count and energy in the process of rock fracture are affected by the angle of two fissures. The cumulative count and accumulated energy count increase with increasing the fissure angle. The cumulative damage of rock at the moment of the sudden increase of stress amplitude is greater than that at the fatigue loading stage. (3) Post-test CT scanning reveals different fracture modes formed from the rock bridge segment, which is greatly affected by the fissure angle. The complexity of the fracture network increases with the increase of the fissure angle, indicating that the rock is different to be fractured with a larger fissure angle. The experimental results are helpful in understanding the fatigue failure mechanism of pre-flawed hollow rock, and provide necessary theoretical supports for the tunnel excavation design, the stability control of surrounding rocks and the long-term stability of jointed rock mass exposed to stress disturbance. © 2022 Academia Sinica. All rights reserved.

引用

页码：1325 / 1337

页数：12

共 24 条

[1]

MARTINI C D, READ R S, MARTINO J B., Observations of brittle failure around a circular test tunnel[J], International Journal of Rock Mechanics and Mining Sciences, 34, 7, pp. 1065-1073, (1997)

[2]

ZIMMERMANN G, ZANG A, STEPHANSSON O, Et al., Permeability enhancement and fracture development of hydraulic in situ experiments in the Äspö Hard Rock Laboratory[J], Rock Mechanics and Rock Engineering, 52, 2, pp. 495-515, (2019)

[3]

WU H, KULATILAKE P H, ZHAO G, Et al., Stress distribution and fracture evolution around a trapezoidal cavity in sandstone loaded in compression, Theoretical and Applied Fracture Mechanics, 104, (2019)

[4]

JABER J, CONIN M, DECK O, Et al., Investigation of the mechanical behavior of 3D printed polyamide—12 joints for reduced scale models of rock mass[J], Rock Mechanics and Rock Engineering, 53, 1, pp. 1-19, (2020)

[5]

HU J, LI S, LIU H, Et al., New modified model for estimating the peak shear strength of rock mass containing nonconsecutive joint based on a simulated experiment, International Journal of Geomechanics, 20, 7, (2020)

[6]

SUN P P, YANG X X, SUN D K, Et al., Geometric and mechanical properties of a shear-formed fracture occurring in a rock bridge between discontinuous joints[J], Bulletin of Engineering Geology and the Environment, 79, 3, pp. 1-16, (2019)

[7]

HOEK E., Rock fracture under static stress conditions, (1965)

[8]

WANG Y, LI C, HAN J, Et al., Mechanical behaviours of granite containing two flaws under uniaxial increasing-amplitude fatigue loading conditions:An insight into fracture evolution analyses[J], Fatigue and Fracture of Engineering Materials and Structures, 43, 9, pp. 2055-2070, (2020)

[9]

WANG Y, LI C H, HAN J Q., On the effect of stress amplitude on fracture and energy evolution of pre-flawed granite under uniaxial increasing-amplitude fatigue loads, Engineering Fracture Mechanics, 240, (2020)

[10]

WANG Y, HAN J Q, LI C H., Acoustic emission and CT investigation on fracture evolution of granite containing two flaws subjected to freeze-thaw and cyclic uniaxial increasing-amplitude loading conditions, Construction and Building Materials, 260, (2020)

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