Article
Engineering, Geological
Wangtao Jiang, Yuanming Lai, Qinguo Ma, Hongwei Li
Summary: The establishment of mechanical model and brittleness index for frozen rocks is crucial for rock mass engineering in permafrost areas and artificial freezing engineering. A novel damage model and brittleness index for frozen rocks are proposed based on statistical damage theory, Hoek-Brown criterion and strain difference function. Triaxial tests on saturated red sandstones under different low temperatures demonstrate the significant influence of confining pressure and low temperature on mechanical properties and brittleness of frozen rocks. The superiority of the proposed damage model and brittleness index is confirmed through comparison with existing models and evaluation methods.
Article
Geochemistry & Geophysics
Liang-Juan Zheng, He-Ping Xie, Zheng-Xuan Xu, Jian-Hui Deng, Dong Wang, Guang-Ze Zhang, Cun-Bao Li, Ru Zhang, Gan Feng
Summary: Water content significantly affects the physical and mechanical properties of rock, leading to rock instability and geologic disasters. Saturated slates have different mechanical properties and failure processes compared to unsaturated slates. AE monitoring shows that the deformation and fracturing of unsaturated slates occur intensely, while in saturated slates, they occur with low energy and uniform distribution. Water content also decreases the brittleness index of unsaturated slates.
Article
Energy & Fuels
Yixin Zhao, Xiaoliang Wang, Yanding Guo, Nima Noraei Danesh, Yaodong Jiang
Summary: This paper investigates the change in rock mechanical properties, specifically the brittleness index, with burial depth. Through experiments and analysis, it is found that the mechanical properties of sandstone vary significantly with depth, and the energy release rate and brittleness index increase with increasing depth.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2022)
Article
Engineering, Geological
Fengqiang Gong, Yunliang Wang
Summary: A new rock brittleness index based on the peak elastic strain energy consumption ratio (PEECR) was proposed in this study to evaluate rock brittleness more accurately. The PEECR was verified based on triaxial compression tests on shale under various confining pressures and analyzed using test data from previous studies on six types of rocks. The results indicate that PEECR can accurately evaluate rock brittleness across various types of rocks and brittleness degrees.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Kaiqiang Geng, Junrui Chai, Yuan Qin, Zengguang Xu, Jing Cao, Heng Zhou, Xianwei Zhang
Summary: This study investigates the energy dissipation mechanism and plastic damage model of alkali-activated slag soil under different curing ages, moduli, and cement, ground granulated blast furnace slag (GGBS), and alkali-activator contents. The results show that the destruction of solidified soil is accompanied by energy dissipation, and the damage to a specimen under load can be expressed as the amount of dissipated energy. Additionally, the influence of the cement, GGBS, and alkali-activator contents are shown to increase through X-ray diffraction (XRD), thermogravimetry (TG/DTG) and nuclear magnetic resonance (NMR) tests.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Engineering, Geological
Xiaobo Liu, Zhenyu Zhang, Zhaolong Ge, Chunlin Zhong, Li Liu
Summary: By conducting uniaxial compressive tests on water-pressurized coal samples, a new energetic brittleness index was proposed to evaluate the brittleness. The study found that pore water enhanced brittle coal strength, but reduced strength of transitional and ductile coal. The new brittleness index showed great superiority in avoiding subjective mechanical parameter determination and could be conveniently calculated from uniaxial compression tests.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Construction & Building Technology
Chulei Fang, Jichao Feng, Shuaishuai Huang, Jun Hu, Wei Wang, Na Li
Summary: The research on recycled aggregate mortar (RAM) was conducted to explore the feasibility of using recycled aggregate instead of river sand in cement mortar. The results showed that recycled aggregate can improve the toughness, flexural strength, and consistency of the mortar. The optimal mechanical properties were achieved when the ratio of recycled aggregate to river sand was 40%.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2022)
Article
Mathematics
Xiaoli Xu, Changqi Yue, Liqi Xu
Summary: Higher temperatures worsen the mechanical properties of rocks, as demonstrated by the decrease in peak stress, ultimate elastic energy, and dissipated energy. A thermal damage constitutive model based on energy dissipation effectively describes the stress-strain curve and post-peak stress drop phenomenon in rock failure. The analysis of rock stress drop from an energy perspective is significant for understanding the brittle fracture mechanism.
Article
Materials Science, Multidisciplinary
Lusheng Wang, Siliang Yan, Miao Meng, Kemin Xue, Ping Li
Summary: Molecular dynamics simulations were used to investigate the defect evolution and mechanical properties of iron under irradiation. The presence of twin boundaries was found to reduce defects and enhance the resistance to irradiation brittleness. The plastic deformation mechanism of single-crystal iron involved atomic slip systems, while irradiation caused a transition in the mechanism. For bicrystalline iron, different grain boundaries exhibited different plastic deformation mechanisms, and irradiation had minimal effect on the plastic deformation.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Construction & Building Technology
Kaiqiang Geng, Junrui Chai, Yuan Qin, Xiaoli Li, Minghan Duan, Da Liang
Summary: This paper conducts dynamic tests on ordinary concrete and basalt fiber reinforced concrete (BFRC) to study the effect of basalt fiber on the performance of concrete. It establishes a brittleness index evaluation method based on the full stress-strain curve and provides a reference for the brittleness evaluation of concrete.
MATERIALS AND STRUCTURES
(2022)
Article
Engineering, Geological
Z. W. Ding, J. D. Jia, Q. B. Tang, X. F. Li
Summary: This study systematically explores the mechanical properties and damage evolution law of coal samples under cyclic loading. The experimental results indicate that cyclic loading enhances the strength of coal masses and leads to more severe failure modes. The input energy and elastic energy increase rapidly with axial stress, while dissipation energy increases slowly. The critical value of the damage variable and the settlement of coal samples are also related to the stress level.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Xiaopeng Yue, Tao Wen, Yuan Gao, Wenjun Jia, Yankun Wang, Mingyi Hu
Summary: The assessment of rock brittleness is crucial for understanding the mechanical properties and engineering behavior of rocks. This study summarizes existing evaluation methods and proposes a new brittleness index. The research findings provide guidance for evaluating and understanding the brittleness variations of red-bed sandstone and cyan sandstone.
APPLIED SCIENCES-BASEL
(2023)
Article
Metallurgy & Metallurgical Engineering
Zhang Jun-wen, Ding Lu-jiang, Song Zhi-xiang, Fan Wen-bing, Wang Shan-yong
Summary: The advance speed of the working face in coal mines affects the fluctuation frequency of abutment pressure in front of the coal body and has a significant impact on the mechanical properties of deep sandstones, with the damage degree increasing with the loading rate.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2022)
Article
Construction & Building Technology
Yongqiang Hou, Shenghua Yin, Shixing Yang, Xin Chen, Huihui Du
Summary: This study explores the influence of average strain rate (ASR) on the mechanical properties, damage evolution, and energy dissipation of cemented tailings backfill (CTB) through laboratory dynamic testing. The results show that both the dynamic peak stress and initial crack stress of CTB increase exponentially with the increase of ASR, indicating a significant strain rate effect. Similarly, the dynamic peak strain and initial crack strain of CTB also increase exponentially with the increase of ASR. Higher ASR and lower cement content in CTB lead to increased deformation and failure. The increase of ASR improves the energy indexes of CTB at the peak stress point, and higher cement content also enhances the energy parameters of CTB. Additionally, a dynamic statistical damage constitutive model of CTB considering ASR was established and verified for accuracy and reliability. The damage failure of CTB occurs in three stages: rapid growth stage, slow growth stage, and stable growth stage. Furthermore, higher strain rate retards the development of cracks inside CTB, inhibiting rapid damage growth. Under impact loading, CTB samples mainly experience axial macroscopic main crack tensile failure and crushing failure. When the average strain rate is above the critical strain rate, crushing failure becomes the primary failure pattern of CTB. When the average strain rate is similar, CTB with higher cement content experiences less damage.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Mechanics
Mingyang Zhai, Lianchong Li, Bin Chen, Qinxi Zhang, Zilin Zhang, Liaoyuan Zhang
Summary: This study investigates the influence of inherent anisotropy on the mechanical properties and brittleness characteristics of deep laminated sandstone. A new brittleness index is proposed based on energy evolution during sandstone failure, which considers the energy transformation characteristics and the effect of confining pressure and bedding plane geometry. Experimental and numerical simulations are conducted to validate the new index and explore the control factors of brittleness anisotropy. The study also discusses the correlation between acoustic emission characteristics and brittleness index. The results provide insights for fracability evaluation and hydraulic fracturing design in deep laminated sandstones.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Engineering, Environmental
Guowen Xu, Chuan He, Jian Yan, Gaoyu Ma
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2019)
Article
Engineering, Environmental
Ziquan Chen, Chuan He, Guowen Xu, Gaoyu Ma, Wenbo Yang
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2019)
Article
Engineering, Environmental
Guowen Xu, Chuan He, Xin Wang
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2020)
Article
Construction & Building Technology
Xiong-Yu Hu, Chuan He, Xiao-Hui Lai, Gabriel Walton, Guo-Wen Xu
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2020)
Article
Engineering, Geological
Guowen Xu, Marte Gutierrez, Chuan He, Wei Meng
Article
Engineering, Environmental
Guowen Xu, Chuan He, Jun Wang, Junbo Zhang
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2020)
Article
Engineering, Environmental
Ziquan Chen, Chuan He, Wenbo Yang, Wenqi Guo, Zheng Li, Guowen Xu
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2020)
Article
Computer Science, Interdisciplinary Applications
Hongwei Fang, Yohchia Frank Chen, Zhenkun Hou, Guowen Xu, Jianxun Wu
COMPUTERS AND GEOTECHNICS
(2020)
Article
Engineering, Geological
Guowen Xu, Chuan He, Jun Wang, Ziquan Chen
ROCK MECHANICS AND ROCK ENGINEERING
(2020)
Article
Engineering, Mechanical
Guowen Xu, Chuan He, Ziquan Chen, Chuankun Liu, Bo Wang, Yulin Zou
ENGINEERING FAILURE ANALYSIS
(2020)
Article
Engineering, Geological
Hongwei Fang, Yohchia Frank Chen, Guowen Xu, Zhenkun Hou, Jianxun Wu
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2020)
Article
Engineering, Geological
Guowen Xu, Chuan He, Ziquan Chen, Qinghao Yang
ENGINEERING GEOLOGY
(2020)
Article
Engineering, Mechanical
Zhengshu He, Chuan He, Gaoyu Ma, Wenbo Yang, Guowen Xu
Summary: This study presents a novel approach to estimate the structural performance of a deteriorated reinforced concrete shield tunnel, with a focus on the spatial correlation and variation of steel corrosion. A random field integrated with Gumbel model is used to simulate the nonuniform steel corrosion. Numerical and analytical models are developed to evaluate the load-bearing capacity of a corroded RC segment. Monte Carlo simulation is performed to estimate the failure probability of a deteriorated RC shield tunnel. An illustrative example investigates the effects of corrosion degree and nonuniformity of steel reinforcements on the structural performance.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Engineering, Civil
Hongwei Fang, Yixiang Xu, Guowen Xu
Summary: The seismic slip line field theory (SLFT) is derived based on the method of characteristic, and the critical slope contour calculated by the SLFT is a convex shape when a high surcharge is imposed on the slope top surface. A simple and robustness failure mechanism is proposed to calculate the static and seismic ultimate bearing capacity of strip footing adjacent to the cohesion-frictional slopes where the critical slope contour shifts from the inside of the slope to the outside of the slope with the increase of the boundary load, and the slope is at the limit state when the critical slope contour is tangent to the slope surface. The influence of slope and footing geometric features, soil parameters, and the seismic load on the bearing capacity is analyzed. The ultimate bearing capacity decreases as the strength parameters decreases, and the slope angle and the seismic coefficient increases. The static and seismic bearing capacity calculated by the proposed method does not require the failure models to be initially assumed, and the results are consistent with those of the other methods.
KSCE JOURNAL OF CIVIL ENGINEERING
(2023)
Article
Engineering, Mechanical
Jiamin Du, Yueheng Shu, Guowen Xu, Chuan He, Chaofan Yao
Summary: This study used statical analysis, similarity model tests and numerical simulations to investigate the influence of geo-stress field on the evolution of lining cracks in soft rock tunnels. The results showed that circumferential crack was the most common type, followed by longitudinal, oblique, and reticulate cracks. The location and length of cracks were affected by the direction of the maximum principal stress. The stress redistribution and fracture pattern of the lining were more complex for larger cross-sectional areas. The study provides valuable insights for the structural design of secondary lining under different geo-stress fields.
ENGINEERING FAILURE ANALYSIS
(2023)
