Article
Engineering, Geological
Liu He, Xudong Lu, Tim Copeland, Jiannan Chen, Jiaxin Yan, Wang Zhao
Summary: The shear rate has a significant impact on the shear mechanical properties of rock joints. This study conducted constant normal load direct shear tests on rock joint specimens under different shear rates to investigate their behavior and failure modes. The results showed that higher shear rates led to a decrease in peak shear strength, an increase in peak shear displacement, and a decrease in residual shear strength. The study also observed that increasing joint roughness coefficients and decreasing joint wall compressive strengths and normal stresses intensified the influence of shear rate on peak shear strength and peak shear displacement. Moreover, the research identified shear-off and wear failure modes, both of which were intensified by higher shear rates. However, as the shear rate increased, the dominant failure mode transitioned from wear to shear-off, especially when joint roughness coefficients, joint wall compressive strengths, and normal stresses decreased. Lastly, the study proposed a modified shear strength correlation model that incorporated shear rate and relevant variables to estimate the shear strength of rock joints. The predicted results demonstrated that the newly proposed model outperformed existing models.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Engineering, Mechanical
Chaolin Wang, Yu Zhao, Cong He, Jing Bi
Summary: In this study, a simple auxiliary device and particle flow code were used to conduct tension-shear tests on red sandstones. The results showed that the mechanical behaviors of the samples were affected by the sample height and base hollow diameter, and there was a transition from shear failure to hybrid tension-shear failure.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Engineering, Environmental
Gianmarco Vallero, Monica Barbero, Fabrizio Barpi, Mauro Borri-Brunetto, Valerio De Biagi, Yoichi Ito, Satoru Yamaguchi
Summary: Within the field of snow mechanics, the shear strength of snow plays a key role in understanding the progressive shear failure of snow interfaces. However, research on the shear behavior at the contact between a snow layer and a solid stiff material is limited. Experimental direct shear tests under different conditions provide valuable insights into the shear strength of snow-mortar interfaces.
COLD REGIONS SCIENCE AND TECHNOLOGY
(2022)
Article
Mechanics
Liang Xue, Xiaodan Ren, Roberto Ballarini
Summary: This paper proposes a new stress decomposition procedure, called shear-normal decomposition, to establish a damage-plasticity constitutive relationship for concrete specifically considering shear failure. The model accounts for the degradation of concrete's mechanical performance through shear, tension, and compression damage variables. It also presents calibration experiments to determine the shear stress-shear strain curve and considers the coupling between tension-shear and compression-shear using a shear damage evolution criterion.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Engineering, Environmental
Dejian Li, Wentao Jia, Xiao Cheng, Lianheng Zhao, Yingbin Zhang, Pengcheng Yu
Summary: This paper establishes a limit state analysis model for the stability of jointed rock slopes with stepped sliding surfaces based on tensile failure and tensile-shear composite failure modes of rock bridges. The influences of key parameters on slope stability are investigated, showing that the existence and different failure modes of rock bridges have significant effects on slope stability.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2022)
Article
Construction & Building Technology
Qiao Liao, Jiangtao Yu, Tianchen Shi, Yuanrui Su
Summary: This study experimentally investigated the mechanical properties of seawater sea-sand engineered cementitious composites (SS-ECC) under various combined tension-shear loads. The results showed that SS-ECC exhibits multiple cracking and micro-cracks with small crack widths under combined tension and shear. The load-displacement curves of SS-ECC can be divided into three stages: elastic stage, steady cracking stage, and failure stage. The study also found that the crack number and maximum resultant force decrease as the loading angle increases. SS-ECC under combined tension and shear demonstrates excellent strength and ductility compared to the control group. The failure law of SS-ECC under combined loading is well described using the generalized twin shear stress strength theory.
JOURNAL OF BUILDING ENGINEERING
(2022)
Review
Metallurgy & Metallurgical Engineering
P. C. Pinazzi, A. J. S. (Sam) Spearing, K. V. Jessu, P. Singh, R. Hawker
Summary: Rock bolts are essential for ground reinforcement underground, with studies showing the need to evaluate the effect of combined loads on their performance. A hybrid failure criterion has been developed to cover all loading conditions, based on 58 un-grouted laboratory tests. The failure criterion presented in this paper can serve as a guide for designing rock bolt capacity under all loading conditions.
MINING METALLURGY & EXPLORATION
(2021)
Article
Engineering, Geological
Yang Zhao, Rui Wang, Jian-Min Zhang
Summary: This paper proposes a tensile failure criterion for transversely isotropic rocks, which distinguishes between the fracturing mechanisms through the rock matrix and along the weak bedding planes. The criterion extends the isotropic tensile failure criterion by constructing an augmented normal stress component and analyzes the rock strength and failure plane orientation in uniaxial tension tests. The proposed criterion is validated with experimental data on four different transversely isotropic rocks and can reproduce various types of rock strength and failure plane orientation variation curves with bedding plane orientation.
Article
Construction & Building Technology
Yong Niu, Guangjian Liu, Zhen Zhong, Jinguo Wang, Ranran Zhang, Bolong Liu
Summary: An extended non-ordinary state-based peridynamic (NOSB-PD) theory is used to study the fracture characteristics of rock-like materials with intermittent flaws under compressive-shear loading. The theory integrates stress-based failure criteria, namely the maximum tensile stress criterion and the Mohr-Coulomb criterion, to determine the tensile and shear failures of flawed rock-like materials. The distribution characteristics of maximum principal stress and shear stress obtained by the NOSB-PD theory are employed to analyze the fracture failure mechanism. The numerical results are validated by experimental data, indicating the capability of the extended NOSB-PD theory in simulating fracture processes under compressive-shear loading.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Engineering, Geological
Hadi Fathipour-Azar
Summary: This paper proposes an interpretable shear strength criterion for rock joints based on the MARS algorithm, and performs sensitivity analysis on the criterion. It also comparatively evaluates the performance of five surrogate soft computing methods for predicting the shear strength of rock discontinuities, and finds that GP, AMT, and RBF models have better prediction performance than MARS and EN models.
Article
Construction & Building Technology
Dowon Park
Summary: The Hoek-Brown failure criterion is effective for estimating the peak strength of isotropic rocks under shear failure, but less accurate for tensile fractures. Previous studies have not considered the influence of the tension cut-off (TC) introduced by Hoek and Brown for deep excavation. In this study, a stability analysis of deep tunnel roofs was performed using the HB yield function with reduced or eliminated tensile strength, revealing a significant impact of TC on the stability of different tunnel cross-sections.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2023)
Article
Construction & Building Technology
Guanghui Tian, Weijian Liu, Haohao Ma, Qingzhao Zhang
Summary: This study proposed a data analysis method for relaxation tests under step loading, which was validated through experiments. The results showed differences in relaxation curve values under different stress levels.
ADVANCES IN CIVIL ENGINEERING
(2021)
Article
Engineering, Mechanical
Yifan Chen, Hang Lin
Summary: The Hoek-Brown criterion is widely used in various fields. This study investigated the deterioration of Hoek-Brown parameters for freeze-thaw multi-fractured rock mass and proposed a new estimation method based on shear test. The values of GSI and mi were found to decrease with the increase of freeze-thaw cycles, following a negative exponential function model.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Construction & Building Technology
Long Cheng, Hui Wang, Xu Chang, Yewei Chen, Feilu Xu, Bafang Zhang, Jiawei An
Summary: Three-dimensional scanning and 3D printing were used to prepare composite rock specimens simulating natural rock laminae for triaxial compression tests to investigate the anisotropic mechanical properties. The results showed that bedding angle, rock composition, and confining pressure affected the mechanical properties of the specimens, with compressive strength showing a nonlinear relationship with confining pressure. The Hoek-Brown strength criterion was able to predict the nonlinear increase in peak strength of the composite rock specimens under different confining pressures.
ADVANCES IN CIVIL ENGINEERING
(2021)
Article
Geosciences, Multidisciplinary
Baohua Guo, Tan Cheng, Jiehao Sun, Shixuan Tian, Yan Chen, Yongbin Niu
Summary: The shear mechanical properties of rock fracture surfaces degrade after multiple dry-wet cycles, with decreased pre-peak shear stiffness and peak shear strength, and increased peak shear displacement. The degradation of these properties increases with the number of dry-wet cycles. The chemistry of the wetting solution has little effect on the mechanical behavior. An empirical formula is proposed to describe the peak shear strength of irregular rock fractures under dry-wet cycling conditions.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Engineering, Geological
Yixiang Song, Da Huang, Duofeng Cen
ENGINEERING GEOLOGY
(2016)
Article
Engineering, Geological
Da Huang, Yixiang Song, Duofeng Cen, Guoyang Fu
ROCK MECHANICS AND ROCK ENGINEERING
(2016)
Article
Engineering, Geological
Duofeng Cen, Da Huang, Feng Ren
Article
Engineering, Geological
Duofeng Cen, Da Huang
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2017)
Article
Engineering, Geological
Da Huang, Duofeng Cen, Guowei Ma, Runqiu Huang
Article
Engineering, Geological
Huang Da, Cen Duo-feng, Huang Run-qiu
ROCK AND SOIL MECHANICS
(2013)