Article
Engineering, Geological
Wengang Dang, Junpeng Chen, Linchong Huang, Jianjun Ma, Xiang Li
Summary: The study found that the shear strength and normal displacement of granular materials under dynamic normal load vary with changes in the normal load, with the peak shear stress decreasing with increasing normal load frequency and shear velocity. Additionally, dynamic normal load can both enhance and reduce the shear strength and normal displacement of granular materials.
ENGINEERING GEOLOGY
(2021)
Article
Engineering, Geological
Wengang Dang, Yu Liu, Shixiao Li, Xiang Li, Linchong Huang, Jianjun Ma
Summary: In this research, direct shear tests were conducted on dredged soil using DJZ-500 shear apparatus to investigate its dynamic frictional behavior under various shear rates, dynamic normal stress frequencies, and amplitudes. The results revealed that shear stress varied periodically with normal stress and exhibited a phase lag with peak shear stress. Dynamic normal stress had both strengthening and weakening effects on shear strength. Therefore, the dynamic frictional behavior of dredged soil depended on shear velocity and the frequency and amplitude of dynamic normal stress.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2023)
Article
Engineering, Geological
Wengang Dang, Junpeng Chen, Linchong Huang
Summary: The study investigated the shear behavior of a rough basalt fracture under different shear velocities, finding that changes in shear velocity can impact the frictional resistance of joints/faults. Peak shear strength tended to increase with increasing shear velocity, but decreased under normal load vibrations. It was also observed that there were phase shifts between peak normal load and peak shear load, as well as peak coefficient of friction, with delays that decreased with increasing shear velocity.
Article
Engineering, Geological
Wengang Dang, Kang Tao, Xinfan Chen
Summary: In this study, direct shear tests were conducted on saw-cut and natural granite fractures using a dynamic shear box. It was found that shear forces and normal displacements exhibited periodic changes and time shifts with oscillated normal loads. Small/large normal load oscillation amplitudes enhanced/reduced the peak shear strength, with a critical point.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2022)
Article
Green & Sustainable Science & Technology
Dong Li, Guanfeng An, Xiangsheng Chen, Wengang Dang, Dongyang Li
Summary: This study proposes an experimental method to determine joint stiffness under constant normal load conditions and investigates the properties of normal and shear stiffness. The results show that joint normal and shear stiffness are time and spatially varying parameters, with normal stiffness being significantly higher than average shear stiffness. Shear velocity has little influence on average shear stiffness but affects instantaneous shear stiffness.
Article
Engineering, Geological
F. Y. Liu, C. Zhu, G. H. Yuan, J. Wang, Z. Y. Gao, J. F. Ni
Summary: Reinforced soil structures are often subjected to both static and dynamic loads. However, experimental data concerning the interaction of soil-geosynthetic interfaces under normal dynamic loads are scarce. This paper reports on a series of large-scale direct shear tests investigating the shear behavior of a gravelly soil-geogrid interface under normal cyclic load conditions.
GEOSYNTHETICS INTERNATIONAL
(2021)
Article
Construction & Building Technology
Saman Khaleghparast, Naj Aziz, Alex Remennikov, Sina Anzanpour
Summary: This study aims to improve the understanding of the performance of conventional rock bolts under shear loading, especially dynamic loading conditions. Static tests were conducted to examine the effect of internal confinement and evaluate energy absorption. The dynamic response of the rock bolts was assessed using a drop hammer. The results showed that using steel tubes for internal confinement prevented concrete cracking and allowed for more shear resistance. The shear performance under high-velocity impact load was found to be 70% of that under static loading conditions.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Xinxin Gao, Ze Gu, Qian Ma, Wen Yi Cui, Tie Jun Cui, Chi Hou Chan
Summary: Driven by the demands for compact interconnects and fast information transfer, research on spoof plasmonic metamaterials has been focused on achieving individual modulation of amplitude or phase at single frequencies due to structural limitations. This study proposes and experimentally demonstrates an ultra-thin reprogrammable modulator consisting of a spoof surface plasmonic polariton (SSPP) waveguide and spoof localized surface plasmon (SLSP) resonators, allowing independent control of amplitude and phase of surface waves. By manipulating the SSPP waveguide and SLSP resonators in real-time, various programmable modulations such as amplitude-shift keying, phase-shift keying, quadrature amplitude modulation, and frequency-shift keying can be achieved. Measurement results confirm the potential applications of the reprogrammable plasmonic metamaterial in integrated circuits and communication systems.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Engineering, Multidisciplinary
Wengang Dang, Xinfan Chen, Xueyou Li, Junpeng Chen, Kang Tao, Qingyue Yang, Zhekai Luo
Summary: This study utilized FLAC3D and FEM-based fluent CFD methods to investigate fluid flow characteristics in rock fractures, revealing that flow characteristics are closely related to both shearing and dynamic normal force.
Article
Engineering, Multidisciplinary
Pengyang Li, Yunshuai Chen, Wei Li, Jian Sun, Jian li, Kai Wang, Quandai Wang
Summary: This study investigates the effect of load force and electrical parameter changes in different directions on the high-frequency vibration output characteristics of a giant magnetostrictive transducer. Measures to reduce amplitude attenuation and improve output stability are proposed based on the results.
ALEXANDRIA ENGINEERING JOURNAL
(2022)
Article
Chemistry, Analytical
Junghee Park, Jongchan Kim
Summary: Interfacial tension varies with temperature, which has an impact on the shear wave velocity. Shear wave velocity is highly sensitive to temperature changes, particularly at low degrees of saturation.
Article
Engineering, Electrical & Electronic
Sha Zhu, Zhijie Chen, Yunxin Wang, Ya Jin, Kunpeng Zhai, Yunping Bai, Jun Tan, Peiyuan Wan, Xu Liu, Wei Li, Ning Hua Zhu
Summary: This paper proposes and demonstrates a photonic multi-format background-free binarily modulated microwave signal generator using a single dual-polarization dual-parallel Mach-Zehnder modulator. The generator features good reconfiguration and switchability, capable of generating microwave signals with multiple modulation methods.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
Henrik Odeen, Lorne W. Hofstetter, Allison H. Payne, Ludovic Guiraud, Erik Dumont, Dennis L. Parker
Summary: The purpose of this study was to develop an efficient MRI pulse sequence for simultaneously measuring multiple parameters correlated with tissue nonviability following thermal therapies. A 3D segmented EPI pulse sequence was used to measure PRFS MR thermometry, T-1 relaxation time, and shear wave velocity induced by FUS push pulses. The results showed that temperature increases and T-1 increases correlated with decreased shear wave velocity, indicating material softening with increasing temperature. This approach holds promise for providing co-registered dynamic measures of multiple parameters, which can help assess tissue nonviability during and after thermal therapies.
MAGNETIC RESONANCE IN MEDICINE
(2023)
Article
Engineering, Electrical & Electronic
Kai Niu, Xuanzhi Wang, Fusang Zhang, Rong Zheng, Zhiyun Yao, Daqing Zhang
Summary: This paper rigorously investigates the dependency of velocity estimation accuracy on target locations and headings in WiFi sensing systems, deriving a closed-form solution and understanding the fundamental limitation of velocity estimation. It also proposes a receiving device selection scheme to optimize performance.
IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS
(2022)
Article
Engineering, Multidisciplinary
E. Yarar, A. Tamer Erturk
Summary: This study numerically investigated the factors affecting average shot velocity in the Surface Mechanical Attrition Treatment (SMAT) process. A numerical model was developed using the finite element method, and the effects of frequency, amplitude, and projection distance parameters on shot velocity were simulated. Response Surface Methodology (RSM) and ANOVA tables were used for evaluation. The results showed that apart from frequency and amplitude, projection distance also had a significant impact on shot velocity.
Article
Construction & Building Technology
Zhi Ding, Xiao Zhang, Shao-Heng He, Yong-Jie Qi, Cun-Gang Lin
Summary: This study investigates the longitudinal behavior of a shield tunnel by designing and constructing a reduced-size indoor model. The results show that the longitudinal settlement of the tunnel follows a normal distribution, with the maximum settlement occurring at the central ring and increasing linearly with the applied load. Stress concentration typically occurs on the side of the tunnel waist under surcharge, resulting in transverse elliptical deformation of the entire structure.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2024)
Article
Construction & Building Technology
Lucia Lopez-de-Abajo, Marcos G. Alberti, Jaime C. Galvez
Summary: Assessing and predicting concrete damage is crucial for infrastructure management. This study quantifies gas concentrations in urban tunnels to achieve this goal.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2024)
Article
Construction & Building Technology
Chao He, Yinghao Cai, Chenqiang Pu, Shunhua Zhou, Honggui Di, Xiaohui Zhang
Summary: This paper investigates the impact of river channel excavation on adjacent metro tunnels and proposes protective measures based on an engineering project in Fuzhou, China. A three-dimensional finite element model is developed to calculate the displacements and distortion of tunnels under different excavation sequences and soil reinforcement measures. Real-time monitoring confirms that the vertical displacements and diametrical distortion of tunnels are primarily caused by the excavation of the river above the tunnels, while horizontal displacements are induced by the excavation next to the tunnels. The study recommends a combination of cement slurry with a portal form and concrete with a plate form for soil reinforcement and tunnel protection.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2024)
Article
Construction & Building Technology
Yaosheng Liu, Ang Li, Feng Dai, Ruochen Jiang, Yi Liu, Rui Chen
Summary: In this study, a hybrid model based on a multilayer perceptron (MLP) and meta-heuristic algorithms was developed to improve blast performance during tunnel excavation. Precise prediction of post-blasting indicators was important for optimization, and a comparison of meta-heuristic algorithms was conducted to find the most suitable model. The results showed that the developed model effectively reduces overbreak areas and quantitatively analyzes the influence of geological conditions.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2024)
Article
Construction & Building Technology
Xiang Shen, Yifan Chen, Liqiang Cao, Xiangsheng Chen, Yanbin Fu, Chengyu Hong
Summary: In this paper, a machine learning-based method for predicting the slurry pressure in shield tunnel construction is proposed. By considering the influence of fault fracture zones and setting the formation influence coefficient, the accuracy of the prediction is significantly improved.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2024)
Article
Construction & Building Technology
Shuying Wang, Zihao Zhou, Xiangcou Zheng, Jiazheng Zhong, Tengyue Zheng, Changhao Qi
Summary: A real-time assessment and monitoring approach based on laser scanning technology and point cloud data analysis was proposed to address the hysteresis in assessing the workability of conditioned soils and the inefficiency in estimating the soil volume flow rate in tunnelling practice. The approach was successfully applied in identifying the workability of conditioned soil and its discharge rate in the EPB shield tunnelling project.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2024)
Article
Construction & Building Technology
Peng Jiang, Benchao Liu, Yuting Tang, Zhengyu Liu, Yonghao Pang
Summary: This study introduces a novel deep learning-based electrical method that jointly inverses resistivity and chargeability to estimate water-bearing structures and water volume. Compared with traditional linear inversion methods, the proposed method demonstrates superiority in locating and delineating anomalous bodies, reducing solution multiplicity.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2024)
Article
Construction & Building Technology
Haoyu Mao, Nuwen Xu, Zhong Zhou, Chun Sha, Peiwei Xiao, Biao Li
Summary: The study focuses on the delineation of rock mass damage zones and stability analysis of underground powerhouse in Lianghekou hydropower station. ESG monitoring system is used to monitor the inner micro-fracture activity of surrounding rock mass in real-time. Engineering analogy method is adopted to forecast the deformation period of surrounding rock mass and analyze the variation characteristics of seismic source parameters. The research results provide references for similar deep underground excavation engineering in terms of design and construction.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2024)
Article
Construction & Building Technology
Junling Qiu, Dedi Liu, Kai Zhao, Jinxing Lai, Xiuling Wang, Zhichao Wang, Tong Liu
Summary: This study focuses on the construction surface cracks of large cross-section tunnels in loess strata of China. The mechanism of surface crack formation is analyzed, and factors such as settlement deformation, construction scheme, and surrounding soil environment are identified as the main contributors. Numerical simulations were conducted to gain a deeper understanding of the influence of factors on surface cracks in loess tunnel construction. Specific measures for prevention and treatment of construction surface cracks are proposed to provide new ideas for surface crack control in loess tunnels.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2024)
Article
Construction & Building Technology
Ting Shang, Jiaxin Lu, Ying Luo, Song Wang, Zhengyu He, Aobo Wang
Summary: The study reveals significant variations in car-following behavior across different types of tunnels and consecutive sections of the same tunnel. As tunnel length increases, the driving stability of following vehicles decreases, but the level of driving safety risk is not positively correlated with tunnel length. Significant vehicle trajectory oscillation is observed within the inner sections of long and extra-long tunnels, and a significant relationship between the acceleration of following vehicles and the location within the tunnel section is found.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2024)
Article
Construction & Building Technology
Rusi Zeng, Zhongwei Shen, Jun Luo
Summary: The urban underground complexes (UUCs) in China have been effective in solving urban problems, but users have expressed dissatisfaction with the internal physical environment. Personal characteristics and environmental factors play significant roles in determining users' satisfaction.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2024)
Article
Construction & Building Technology
Gabriel Lehmann, Heiko Kaeling, Sebastian Hoch, Kurosch Thuro
Summary: Analysing and predicting the advance rate of a tunnel boring machine (TBM) in hard rock is important for tunnelling projects. This study focuses on small-diameter TBMs and their unique characteristics, such as insufficient geotechnical information and special machine designs. A database of 37 projects with 70 geotechnically homogeneous areas is compiled to investigate the performance of small-diameter TBMs. The analysis shows that segment lining TBMs have higher penetration rates, and new approaches for the penetration prediction of pipe jacking machines in hard rock are proposed.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2024)
Article
Construction & Building Technology
Ting Ren, Ming Qiao, Jon Roberts, Jennifer Hines, Yang-Wai Chow, Wei Zong, Adrian Sugden, Mark Shepherd, Matthew Farrelly, Gareth Kennedy, Faisal Hai, Willy Susilo
Summary: Long-term exposure to coal and silica dust during underground tunnelling operations is a growing concern. To bridge the gap between knowledge in dust exposure monitoring and frontline workers, a virtual reality educational tool was developed to visualize ventilation and dust flow characteristics. This tool allows workers to better understand decision-making and best practices for dust controls.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2024)
Article
Construction & Building Technology
Dong Lin, Zhipeng Zhou, Miaocheng Weng, Wout Broere, Jianqiang Cui
Summary: Metro systems play a vital role in the transportation, economic, environmental and social aspects of cities. The uncertainties in construction, passenger comfort and safety, as well as efficiency and reliability of the metro system, have been widely studied. Metro systems influence urban development and have a positive impact on housing prices, public health, and environmental quality. Further research is needed to fill the research gaps and make recommendations for future studies.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2024)
Article
Construction & Building Technology
Wei Yu, Bo Wang, Xin Zi, Jie Dong
Summary: In this study, a whole-process analytical theory for the coupled deformation of deep circular tunnel surrounding rock and prestressed yielding anchor bolt (cable) system is derived and validated through numerical simulations. The results show that anchor bolts (cables) can significantly reduce the convergence of surrounding rock, and factors such as support timing and anchor cable length have important effects on the support effectiveness.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2024)