Article
Engineering, Civil
Qiang Mao, Matteo Mazzotti, Mustafa Furkan, Aaron Hicks, Ivan Bartoli, Emin Aktan
Summary: Characterization and evaluation of bridge substructures using structural identification methods face challenges in assessing substructure characteristics, especially in determining embedded depth, highlighting the need for further research and development in this area.
ENGINEERING STRUCTURES
(2021)
Article
Geochemistry & Geophysics
Yanli Wu, Mowei Qiu, Shaokun Ma, Xinlei Gao, Yahong Han
Summary: This paper analyzes the hanger force and main arch stability of long-span CFST arch bridge using the finite element method. Through the study of the Shenzhen Rainbow Bridge project, the axial force, internal force, and stability of the arch bridge are examined. The research findings provide a clearer understanding of the load-bearing mechanism of CFST arch bridge and offer valuable insights for its design and construction.
Article
Engineering, Civil
Wen-ming Zhang, Xiao-yi Zhang, Gen-min Tian
Summary: This study proposes a calculation method for hanger force optimization considering the live load effect for a single-main-span suspension bridge with short extended spans. The optimized hanger forces are uniform and result in two flat bending moment envelopes for the entire main beam, indicating an efficient use of material. The main beam displacement manifests as the downwarping of the extended spans and arching of the main span.
Article
Engineering, Multidisciplinary
Suleyman Adanur, Ebru Kalkan Okur, Ahmet Can Altunisik, Murat Gunaydin, Bashir Rahmoun Rahwan
Summary: The Bosphorus Suspension Bridge in Istanbul, Turkey, has great geopolitical importance as it connects the Asian and European sides. Recently, the inclined hanger configuration of the bridge was changed to vertical ones, and through three-dimensional finite element analysis, it was found that the vertical hanger configuration has a positive effect on the bridge's vertical displacement and internal forces.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
Article
Computer Science, Information Systems
Ebenezer Fiifi Emire Atta Mills, Siegfried Kafui Anyomi
Summary: This paper proposes a hybrid two-stage robustness approach for portfolio construction that evaluates the efficiency of candidate stocks using a dynamic slack-based measure data envelopment analysis model and determines optimal weights using a robust mean-variance-Entropic Value-at-Risk model. The method reduces computational complexity, increases robustness, and provides a comprehensive evaluation of stocks under different financial decisions.
JOURNAL OF KING SAUD UNIVERSITY-COMPUTER AND INFORMATION SCIENCES
(2022)
Article
Chemistry, Inorganic & Nuclear
Rui-Ying Ren, Chang-Yuan Su, Ting Shao, Zhi-Xu Zhang, Pei-Zhi Huang, Yi Zhang, Qiang-Qiang Jia, Da-Wei Fu
Summary: In this study, the dehydration-activated solid-to-solid structural phase transition of a two-dimensional hybrid double perovskite was successfully achieved. The material exhibited good stability in multiple reversible switching during dielectric tests, contributing to the further exploration of properties and potential applications of hybrid double perovskites.
DALTON TRANSACTIONS
(2022)
Article
Construction & Building Technology
Mohamed F. M. Fahmy, Amr M. A. Moussa, Zhishen Wu
Summary: The aim of this paper is to comprehensively evaluate existing works on precast bridge piers. The study considers construction techniques, structural systems, and seismic response. The research classifies construction techniques into five different systems and evaluates the seismic response of 50 experimentally tested precast bridge piers. The findings suggest that the fully precast post-tensioned system is a promising construction technique for ensuring the resilience performance of bridge piers. This research is important for the construction of modern sustainable cities.
ADVANCES IN STRUCTURAL ENGINEERING
(2023)
Article
Multidisciplinary Sciences
Alvaro Gaute-Alonso, David Garcia-Sanchez, Carlos Alonso-Cobo, Inigo Calderon-Uriszar-Aldaca
Summary: This article presents a comparative analysis of current cable force monitoring techniques. It also includes the experience of three cable stress monitoring techniques during the construction phase, namely the installation of load cells, unidirectional strain gauges, and the vibrating wire technique with accelerometers. The advantages and disadvantages of each technique are highlighted in the context of the construction process of the Tajo Viaduct, one of the most unique viaducts recently built in Spain.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Civil
Jingquan Wang, Jiaping Liu, Zhen Wang, Tongxu Liu, Jianzhong Liu, Jian Zhang
Summary: Accelerated bridge construction (ABC) is increasingly popular in China, with ultra-high-performance concrete (UHPC) considered as a competitive option to address the challenges. A cost-effective UHPC has been developed to potentially build critical zones of precast bridges.
JOURNAL OF BRIDGE ENGINEERING
(2021)
Article
Engineering, Electrical & Electronic
Somnath Khatua, Debaprasad Kastha, Santanu Kapat
Summary: This article introduces a two-stage 48-V voltage regulator module with a hybrid switched-capacitor converter in the first stage, showcasing efficient regulation ability, scalability, and a flat high-efficiency curve for the first stage. The second-stage multiphase buck converter also exhibits flat high-efficiency characteristics through phase shedding. The article also presents steady-state circuit operation, analysis of the first-stage converter, a discrete-time model, design guidelines for the two-stage converter, and experimental results showing a relatively flat high-efficiency profile and faster load transient response.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Yufei Li, Fei Diao, Yue Zhao
Summary: This article proposes a simplified two-stage model predictive control method for a hybrid multilevel converter with floating H-bridge, which can significantly reduce the computational burden and ensure the best current tracking performance.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Construction & Building Technology
Sanghyeon Cho, Jungho Choi, Heeyoung Lee, Wonseok Chung
Summary: This study developed and demonstrated a composite rigid-frame bridge with a construction joint and anchors, and evaluated the structural performance and composite behavior of different joints. The results showed that the construction joint with anchors exhibited excellent structural performance and composite behavior.
INTERNATIONAL JOURNAL OF CONCRETE STRUCTURES AND MATERIALS
(2023)
Article
Chemistry, Physical
Christoph Brunken, Markus Reiher
Summary: A protocol for the fully automated construction of quantum mechanical-classical hybrid models has been introduced, extending a previous approach on system-focused atomistic models. The QM/SFAM approach evaluates the QM region based on first principles to accurately describe atomic forces, allowing for high fidelity and complete automation. This method eliminates dependence on pre-existing parameters and enables convenient redefinition of the QM region during molecular exploration through a local reparametrization scheme.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Engineering, Civil
Neryvaldo Galvao, Jose C. Matos, Rade Hajdin, Luis Ferreira, Mark G. Stewart
Summary: The ageing of bridges in developed countries and the increase in bridge collapses have highlighted the need for more sophisticated assessment procedures for structural safety. This research aims to quantify the impact of construction errors on the safety of a bridge by considering probabilistic models characterizing the occurrence rate and severity of these errors. The novelty of this paper lies in considering the additional uncertainty of construction errors and using refined numerical methods to estimate the probability of failure more accurately.
ENGINEERING STRUCTURES
(2022)
Article
Construction & Building Technology
Huiteng Pei, Lijun Jia, Jiawei Li, Kewei Li, Ruijie Xia
Summary: The mechanical properties of steel-concrete joints during construction were studied using the Mao Port Bridge in Shanghai as a case study. Through site construction monitoring, finite element calculation, and refined modeling, the mechanical properties of the bridge and the joint under construction conditions were investigated. The results showed that the analysis of the bridge and the joint agreed with the measured values, and the compressive stresses in the main span varied in a zigzag pattern during construction. The lifting of the mid-span steel beam resulted in compression at the joint, with longitudinal stresses decreasing in the steel structure and increasing in the concrete structure.
Article
Construction & Building Technology
Debalina Ghosh, Ammar Abd-Elssamd, Zhongguo John Ma, Diana Hun
Summary: High-early-strength fiber-reinforced self-compacting concrete (FRSCC) is a practical material for the precast concrete industry to increase production capacity. By developing high-early-strength FRSCC mixtures and controlling costs within a certain range, strength requirements were achieved, and the influence of different fiber reinforcements on concrete properties was analyzed.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Engineering, Geological
Y. L. Zheng, Z. J. Ma, S. Q. Yang, X. B. Zhao, L. He, J. C. Li
Summary: This study investigated the impact of rock properties on microwave fracturability and proposed a multi-parameter linear regression model for igneous rocks' Microwave Fracturability Index (MFI). Results showed the significance of factors like effective dielectric loss factor and average grain size, providing an easy assessment method based on petrographic photomicrographs and P-wave velocity measurement.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Engineering, Civil
Lu Liu, Zhouhong Zong, Zhongguo John Ma, HaiMin Qian, Lu Gan
Summary: This study investigated the behavior and failure modes of PSRC piers under close-in blast loading through reduced-scale field tests. The results showed that PSRC piers exhibited specific failure characteristics compared to monolithic piers under different explosion conditions. It was found that by designing structural parameters such as the number of segments, slenderness ratio, and shear key, the localized and overall residual deformation of PSRC piers could be reduced effectively.
JOURNAL OF BRIDGE ENGINEERING
(2021)
Article
Engineering, Civil
Qi Cao, Xianrui Lv, Xiaojun Li, Rongxiong Gao, Zhongguo John Ma
Summary: This study investigated the behavior of concrete-encased-steel filled CFRP tube cylinders under axial compression, showing that prestress improves CFRP performance and increasing CFRP layers enhances axial compression behavior. Additionally, CFRP provides more effective confinement for small cross-sectional area section steel.
Article
Engineering, Civil
Jie Liu, Huiping Huang, Zhongguo John Ma, Juanjuan Chen
Summary: This paper experimentally investigated the interface shear transfer behavior between concretes cast at different times after shear reinforcement corrosion. The results show that shear reinforcement corrosion leads to a decrease in shear capacity and failure load of cold joints, while increasing interface deformation. Additionally, a more ductile shear transfer behavior was observed after shear reinforcement corrosion.
ENGINEERING STRUCTURES
(2021)
Article
Construction & Building Technology
Yulin Zhan, Zhilun Li, Zhao Chen, Junhu Shao, Fanfan Yue, Zhongguo John Ma, Shuoshuo Zhao
Summary: This study investigates the shear behavior of keyed tooth joints (KTJ) in precast concrete segmental bridges through experimental tests and numerical simulation. The results show that KTJ with epoxy bonding has significantly higher shear capacity than dry KTJ. Additionally, large KTJ performs better in shear than KTJ with multiple small keys. Adding internal reinforcements strengthens the connection and changes the failure mode from shear to crushing. Finite element models indicate that adding longitudinal reinforcement is more effective than stirrups in enhancing the load-bearing capacity and ductility of the reinforced large KTJ. Bakhoum’s formula provides the most accurate prediction for the experimental results. The study suggests using epoxied joint with reinforced large shear key in precast concrete segmental bridges.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Engineering, Civil
Wei-Jian Yi, Ye Li, Hui Chen, Zhongguo John Ma, Ke-Jing Zhou, Yuan Huang, Yun Zhou
Summary: This study proposes a shear design equation based on a cracking strut-and-tie model for reinforced concrete D-regions. The equation simplifies the design process, reduces uncertainty, and improves structural reliability, based on regression analysis and simulated test data.
ENGINEERING STRUCTURES
(2022)
Article
Construction & Building Technology
Yulin Zhan, Zhilun Li, Zhao Chen, Junhu Shao, Fanfan Yue, Fang Liu, Zhongguo John Ma
Summary: Precast concrete segmental bridge (PCSB) has gained rapid development due to its advantages of fast construction speed, minimal environmental impact, easy quality control, and cost-effectiveness. Key tooth joint (KTJ), as the critical connection part of PCSB, has limited research on its performance under repeated loading. This study conducts experimental and numerical investigations on the behavior of adhesive KTJ under repeated loading. The study includes different configurations of KTJ, such as geometries of keys, number of keys, reinforcement in the key, and steel fibers in concrete. The results show that KTJ with small keys and a single large key exhibit similar behavior when the contact areas are the same, but the large key is stiffer. Compared to monotonic loading, KTJ's load-bearing capacity and stiffness are significantly reduced under repeated loading due to damage accumulation in concrete. Adding steel fibers in the concrete can enhance the ductility of KTJ, while adding reinforcement in the large key can reduce damage accumulation effects. The developed finite element models of KTJ under repeated loading align well with experimental results in terms of cracking development, load-displacement behavior, and load carrying capacity.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Engineering, Civil
Zhi-Qi He, Jiatong Chen, Zhao Liu, Zhongguo John Ma
Summary: The steel-concrete hybrid girder bridge structure combines steel and concrete members to reduce bridge self-weight and the effects of concrete creep and shrinkage. The rational length and location of the steel portion are critical in design. The system equivalence method provides a way to determine the length ratio and establish its relationship with the span ratio. The proposed analytical approach is validated by case studies and is effective for the preliminary design of hybrid girder bridges.
JOURNAL OF BRIDGE ENGINEERING
(2023)
Article
Construction & Building Technology
Bingcong Chen, Junping Zhang, Airong Liu, Liwen Zhang, Zhujian Xie, Xiaowei Ouyang, Zhongguo John Ma
Summary: Using oyster shell powder (OSP) in magnesium phosphate cement (MPC) production reduces waste pollution and promotes the development of environmentally friendly cement. This study examines the effects of OSP on MPC hydration and strength development through a compressive strength experiment using different amounts of OSP (0% to 12%) at curing times of 7, 14, and 28 days. The results show the formation of a new reactant CaHPO4·2H2O, which optimizes the strength of the cement matrix. The substitution of OSP can reduce the cost of MPC without compromising its strength.
ADVANCES IN CEMENT RESEARCH
(2023)
Article
Engineering, Civil
Zhi-Qi He, Jiatong Chen, Zhao Liu, Zhongguo John Ma
Summary: Improper design and detailing of the anchorage zone in prestressed concrete structures often result in bursting cracking along the tendon path. Previous studies mainly rely on numerical simulation, lacking explicit approaches for practical use. This study presents an analytical approach for predicting the first bursting cracking loads in the anchorage zone, taking into account the biaxial stress state and the contribution of bursting reinforcement. The approach is validated with test data and applied in the cracking analysis of a real bridge, showing its accuracy and convenience for application.
Article
Construction & Building Technology
Nolan W. Hayes, Farid Benboudjema, Yann Le Pape, Zhongguo John Ma
Summary: Alkali-silica reaction (ASR) is a harmful chemical reaction between alkali hydroxyl ions and silica in concrete. A new model has been developed to predict the expansion of concrete structures affected by ASR. The model combines existing models for ASR advancement, casting direction anisotropic expansion, stress-dependent anisotropic expansion, and material property evolution dependent on the degree of ASR expansion. The calibrated model accurately predicts the ASR expansion of large-scale reinforced concrete specimens.
CEMENT AND CONCRETE RESEARCH
(2023)
Article
Construction & Building Technology
Debalina Ghosh, Zhongguo John Ma, Diana Hun
Summary: CSA cement is an alternative cement that can benefit precast, rapid, and low-temperature concrete construction. However, its low workability and short setting time hinder its application in the construction industry. The use of OPC and GGBFS in CSA-based composite binder can improve workability and setting time while maintaining early strength and low carbon footprint.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Debalina Ghosh, Paula Bran Anleu, Yann Le Pape, Zhongguo John Ma
Summary: This study investigates the impact of time delay between consecutive extruded layers on the mechanical performance of printed concrete. A series of specimens with different printing delays were prepared using a mix designed by Quikrete. The results show that the time delay between consecutive layers affects fracture properties, mechanical performance, and workability retention. This study fills the knowledge gaps in understanding the effect of interlayer time-lapse on fracture properties in printed concrete research and can assist researchers in optimizing and estimating the performance of printed concrete.
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
(2023)
Article
Engineering, Civil
Ning Ning, Zhongguo John Ma, Jigang Zhang, Shan Jiang
Summary: In this study, the properties of Ultra-Lightweight Insulated Cementitious Composites (ULICC) were experimentally investigated. The use of Hollow Glass Microspheres (HGM) improved the thermal insulation capacity. The effects of water to blind ratio (W/B) and HGM volume content on the mechanical and thermal properties of ULICC mixtures were considered. The results showed that ULICC had a dry density of 1071-1358 kg/m3, tensile strength of 2.25-3.09 MPa, and compressive strength of 35.2-57.1 MPa. The thermal conductivity coefficients ranged from 0.193 W/m.K to 0.227 W/m.K. Infilled RC frames retrofitted with ULICC exhibited higher lateral carrying capacity and improved energy efficiency.
