bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding Formation and Roles of Ni(II) Aryl Amido and Ni(III) Aryl Amido Intermediates in Ni-Catalyzed Electrochemical Aryl Amination Reactions
Authors: Luo Jian , Davenport Michael , Callister Chad , Minteer Shelley , Ess Daniel , Liu Tianbiao
Published: November 2022

Ni-catalyzed electrochemical aryl amination (e-amination) is an attractive, emerging approach to forging C−N bonds as it uses air-stable Ni catalysts and efficiently proceeds at room temperature. However, in-depth mechanistic understandings of this new C−N cross-coupling methodology remain underexplored. Herein, extensive experimental and computational studies were conducted to examine the mechanism of Ni-catalyzed electrochemical aryl amination reactions. The results suggest coordination of an amine to the Ni(II) catalyst occurs before the cathodic reduction and oxidative addition steps. A stable Ni(II) aryl amido intermediate is produced from the cathodic half-reaction, a critical step in controlling the selectivity between cross-coupling and undesired homo-coupling reaction pathways. In addition, redox-active bromide in the supporting electrolyte functions as a redox mediator to promote the oxidation of the stable Ni(II) aryl amido intermediate to a Ni(III) aryl amido intermediate. Subsequently, the Ni(III) aryl amido intermediate undergoes facile reductive elimination to provide a C−N cross-coupling product at room temperature. These mechanistic insights about the Ni-catalyzed aryl e-amination are valuable for understanding and developing new Ni-catalyzed aryl e-amination reactions and also other Ni-catalyzed electrosynthetic reactions such as C−C and C−O cross-couplings.
Hydride superconductor structures of LaH10, EuH9, and UH8 rationalized by electron counting and Jahn-Teller distortions in a covalent cluster model
Authors: Morgan Harry , Alexandrova Anastassia
Published: November 2022

The superconducting hydrides LaH10, EuH9 and UH8 are studied using chemically intuitive bonding analysis of periodic and molecular models. We find trends in the crystallographic and electronic structures of the materials by focusing on chemically meaningful building blocks in the H sublattice. Atomic charge calculations, using two complementary techniques, allow us to assign oxidation states to the metals and divide the H sublattice into neutral and anionic components. Cubic [H8]q- clusters are an important structural motif, and molecular orbital analysis of this cluster in isolation shows the crystal structures to be consistent with our oxidation state assignments. Crystal orbital hamilton population analysis confirms the applicability of the cluster model to the periodic electronic structure. A Jahn-Teller distortion predicted by MO analysis rationalises the distortion observed in EuH9. Additionally, the performance of analytical methods at high pressures are tested and recommendations for future studies are given. These results demonstrate the value of simple bonding models in rationalizing chemical structures under extreme conditions.
A radioiodinated rucaparib analogue as an Auger electron emitter for cancer therapy.
Authors: Destro Gianluca , Chen Zijiun , Chang Chung Ying , Fraser Claudia , Dias Gemma , Mosley Michael , Guibbal Florian , Gouverneur Veronique , Cornelissen Bart
Published: November 2022

Introduction: Radioligand therapy (RLT) is an expanding field that has shown great potential in the fight against cancer. Radionuclides that can be carried by selective ligands such as antibodies, peptides, and small molecules targeting cancerous cells have demonstrated a clear improvement in the move towards precision medicine. Poly (ADP-ribose) polymerase (PARP) is a family of enzymes involved in DNA damage repair signalling pathway, with PARP inhibitors olaparib, talazoparib, niraparib, veliparib, and rucaparib having FDA approval for cancer therapy in routine clinical use. Based on our previous work with the radiolabelled PARP inhibitor [18F]rucaparib, we replaced the fluorine-18 moiety, used for PET imaging, with iodine-123, a radionuclide used for SPECT imaging and Auger electron therapy, resulting in 8-[123I]iodo-5-(4-((methylamino)methyl)phenyl)-2,3,4,6-tetrahydro-1H-azepino[5,4,3-cd]indol-1-one, ([123I]GD1), as a potential radiopharmaceutical for RLT. Methods: [123I]GD1 was synthesised via copper-mediated radioiodination from a selected boronic esters precursor. In vitro uptake, retention, blocking, and effects on clonogenic survival with [123I]GD1 treatment were tested in a panel of cancer cell lines. The enzymatic inhibition of PARP by GD1 was also tested in a cell-free system. The biodistribution of [123I]GD1 was investigated by SPECT/CT in mice following intravenous administration. Results: Cell-free enzymatic inhibition and in vitro blocking experiments confirmed a modest ability of GD1 to inhibit PARP-1, IC50= 239 nM. In vitro uptake of [123I]GD1 in different cell lines was dose-dependent, and the radiolabelled compound was retained in cells for more than 2 h. Significantly reduced clonogenic survival was observed in vitro after exposure of cells for 1 h with as low as 50 kBq of [123I]GD1. The biodistribution of [123I]GD1 was further characterized in vivo showing both renal and hepatobiliary clearance pathways with a biphasic blood clearance. Conclusion: We present the development of a new theragnostic agent based on the rucaparib scaffold and its evaluation in in vitro and in vivo models. The data reported show that [123I]GD1 may have the potential to be used as a theragnostic agent.
Competencias socioemocionales en tiempos de COVID-19. Pensando la enseñanza desde la experiencia percibida por egresados de ingeniería
Authors: Paoloni Paola Verónica , Schlegel Daiana
Published: November 2022

En este trabajo se describe la experiencia percibida sobre recibirse en tiempos de pandemia de un grupo de egresados de la Facultad de Ingeniería de la Universidad Nacional de Río Cuarto (Argentina) durante el año 2020. Se identifican así las competencias que los participantes del estudio valoran como clave para la inserción y desarrollo profesional en tiempos de crisis económica, social y sanitaria. Los datos fueron recabados mediante entrevistas biográficas. A partir de los hallazgos obtenidos se proponen líneas de actuación vinculadas al diseño de tareas académicas como oportunidades para desarrollar competencias socioemocionales.
Predicción de la deformación en la corteza del Volcán – Nevado del Ruíz en el año 2020 mediante información troposférica TROPOMI, técnica DInsar y redes neuronales
Authors: Hernández Santana Juan Sebastián
Published: November 2022

El Volcán Nevado del Ruíz situado entre los límites de los Departamentos del Caldas y Tolima en Colombia presentó un comportamiento inestable en el trascurso del año 2020, dicha actividad volcánica conllevó a efectos secundarios en la corteza, es por ello que la predicción de deformaciones se torna como menester de los geocientíficos. En el transcurso de la investigación presentada se dispuso el uso de variables troposféricas, tales como evapotranspiración, índice de aerosoles UV, monóxido de carbono, dióxido de nitrógeno, metano, temperatura superficial, entre otros; para entrenar un conjunto de redes neuronales que puedan predecir el comportamiento de la fase resultante de un interferograma sin desenrollar con la técnica DInSAR, cuyo objetivo principal sea identificar y caracterizar el comportamiento de la corteza con base en las condiciones del entorno. Para lo anterior, se realizó la recolección de variables, la conformación de un modelo lineal generalizado y el conjunto de redes neuronales. Posterior al entrenamiento de la red, se realizó la validación con los datos de testeo, otorgando un MSE de 0,17598 y, un r – cuadrado asociado de aproximadamente 0,88454. El modelo resultante permitió la obtención de un conjunto de datos con exactitud temática buena, reflejando el comportamiento del volcán en el año 2020 dado un conjunto de características del ambiente.
INDEKS PEMBANGUNAN MANUSIA PADA KABUPATEN/KOTA DI SUMATERA UTARA: EFEK MEDIASI BELANJA MODAL
Authors: Pekiningrum Oktaviani , Wibowo Puji
Published: November 2022

Fiscal decentralization gives local governments the authority to use revenues to finance local expenditure, one of which is expenditures intended to improve the quality of human development. This study aims to analyze the effect of Local Own Source Revenue (PAD), Special Allocation Funds (DAK), and Surplus of Budget Financing (SiLPA) on the Human Development Index (IPM) through capital expenditure on districts/cities in North Sumatra. This study uses panel data consisting of time series data for 2015-2019 and cross section data for 33 districts/cities in North Sumatra. Hypothesis testing is done by multiple linear regression and path analysis. The results of the study proved that DAK and SiLPA have a positive impact on capital expenditures, while PAD has no impact on capital expenditures. Meanwhile, PAD and DAK directly have a significant positive effect on HDI, while SiLPA has no effect on HDI. In addition, PAD, DAK, and SiLPA indirectly have no significant effect on HDI through capital expenditure.
MENEROPONG DETERMINAN OPINI LKPD KABUPATEN/KOTA DI SUMATERA UTARA
Authors: Alal Maula Muhammad Iqbal , Wibowo Puji
Published: November 2022

The financial reports of lower level governments in North Sumatra Province still require serious attention because there are several regions that have not yet obtained unqualified opinions. This study aims to analyze the factors that influence BPK's audit opinion on those financial statements. This research observes financial reports and reports on the results of BPK audits during the 2016-2018 period. The sample selection method was purposive sampling and obtained 31 districts / cities. The panel data analysis used in this research is the random-effect model. Based on the results of statistical tests, the number of audit findings is proven to have a negative impact on the quality of financial reports. Meanwhile, the level of financial statement disclosure and regional characteristics cannot explain the variation in audit opinion between regions.
STRATEGI DALAM MENGATASI PENGANGGURAN AKIBAT COVID-19 DI KELURAHAN SUKAGALIH KOTA BANDUNG
Authors: Dinar Mohamad Ibnu , Sifa Nurul , Nurfahmiyati Nurfahmiyati
Published: November 2022

The problem of unemployment in Sukagalih Village is caused by the many economic sectors that have been affected by the emergence of the COVID-19 pandemic. Unemployment that occurs is caused by several factors, such as the many occurrences of layoffs (Termination of Employment), the PPKM policy (Enforcement of Restrictions on Community Activities) or Work From Home (WFH) rules. The purpose of this study is to determine the condition of unemployment due to COVID-19 and strategies to overcome unemployment. This research is categorized as a field research using qualitative descriptive methods and using primary data and secondary data collected using interview guidelines. In determining the strategy of reducing unemployment, this study uses triangulation techniques to test the validity of the data. There are three main reasons revealed by informants from the community that they have not or are not working, namely the COVID-19 pandemic, age constraints, and having a history of illness. The results of this study indicate that there are special strategies in overcoming the unemployment problem due to COVID-19 in Sukagalih Village, including providing job training and increasing job vacancies.
FAKTOR-FAKTOR YANG MEMENGARUHI PENERIMAAN PAJAK PENGHASILAN MINYAK BUMI DAN GAS ALAM
Authors: Putra Metly Randika
Published: November 2022

The purpose of this research is to determine the factors that influence the petroleum dan natural gas income tax in the production sharing contract. Tests were carried out using 450 observations of petroleum production KKKS and 401 observations of natural gas production KKKS for for the period 2010-2016. Multiple linear regression of panel data using a random effect model on petroleum production KKKS shows that (1) cost recovery and (2) KKKS size have a negative effect, (3) first tranche petroleum, (4) lifting, (5) price and (6) Rupiah exchange rate against USD has a positive effect on petroleum income tax revenue. In Natural Gas Production KKKS, the variables (1) cost recovery and (2) KKKS size have a negative effect, (3) first tranche petroleum and (4) lifting has a positive effect on natural gas income tax revenue.
Research on the Connected Effect of Separated Bridges Based on a Large-Span Continuous Rigid Frame Bridge
Authors: Xu Zhimin
Published: November 2022

Prestressed concrete continuous rigid frame bridge is one of the main types of long-span bridges due to its mature construction technology and low cost during construction and operation. The corresponding design theory and construction technology were focused on the control and prevention technology of cracking and deflection. Based on an actual bridge inspection, obvious connected effect of separated structures was found that additional deformation and stress increase of the amplitude structure induced by the influence of the central transverse connection (diaphragm, central guardrail consolidation base, etc. ) can not be ignored. Suggestions including raising safety coefficient or adopting refined analysis model are provided.
Investigation on the Flexural Behavior of Reinforced UHPC T-Beams with Different Tensile Strain-Hardening Properties of Base Materials
Authors: Alsomiri Mujahed , Liu Zhao
Published: November 2022

Ultrahigh performance concrete (UHPC) has been broadly endorsed for many applications in the construction industry due to its superior mechanical properties and excellent durability. Nevertheless, UHPC utilization as full and large structural components is still limited due to the lack of standardized design guidelines and consistent mechanical models. This study presents a numerical investigation on the flexural behavior of UHPC T-beams under the influence of the tensile grade of UHPC, and the reinforcement ratio. The behavior is studied under three conditions relating the UHPC tensile strain to the reinforcement yielding strain. That is, UHPC peak tensile strain is smaller than, equal to, or larger than the yielding strain of the rebar, reflecting the sequence of crack localization and yielding of rebars. Each condition is examined against a reinforcement ratio ranging from low to high ratio. The nonlinear finite element modeling approach is validated by experimental data available in the literature.
Wind Induced Vibration Performance of Suspended Double-deck Flat Box Girder Bridge
Authors: Hong Guang , Li Jiawu , Wang Jiaying , Wang Jun , Wang Feng , Li Yu
Published: November 2022

The paper researches the wind vibration performance of suspended double-deck streamlined bridge deck using the wind tunnel test and numerical simulation. Studies shown that for suspended double- deck bridge, due to the aerodynamic interference of the upper deck, the lower deck is driven by a vertical vibration negative damping, and the vertical vibration is significantly changed. The pressure distribution of the upper deck and the upper edge of lower deck did not change. The wind load acts on the upper edge of lower deck, and the minus attack angle was generated. With the generation, migration and shedding of large-scale vortices at the lower edge of the lower deck, the lower deck occurs the bending-torsional coupling "soft flutter". Moreover, due to the structural static coupling between the upper deck and the lower deck, the bending-torsional soft flutter at the lower deck induces the bending-torsional soft flutter of the double-deck bridge deck.
Effect of Short-Term Shrinkage on Deck Concrete of a Rail-Cum-Road Composite Truss Bridge
Authors: Li Dewang , Chen Huating , Zhang Wenxue , Zhu Xiufu
Published: November 2022

Rail-cum-road truss bridges are rapidly developing, and frequent cracking in freshly poured deck concrete is of great concern. For the performance of such a load-bearing deck, it is necessary to understand its stress status due to short-term shrinkage. Taking a newly-constructed rail-cum-road truss bridge as the case project, this paper, by ANSYS finite element simulation, mainly analyzed the stress distribution in deck concrete under short-term action of shrinkage. Shrinkage of one deck panel and two companion specimens shortly after the concrete pouring was measured through in- situ testing. It was found that the free shrinkage of companion specimens at 40 days is 140~150 micro strains, significantly higher than that indicated by the current code. Under the action of short- term shrinkage, tensile shrinkage stress in the magnitude of 1,5~3,5 MPa is present in the deck, triggering potential cracking, and its effect shall therefore not be neglected.
Punching behavior of a novel steel-UHPFRC composite bridge deck slab
Authors: Shen Xiujiang , Shao Xudong , Lu Jingyu , Cao Junhui , Wang Yang
Published: November 2022

A novel steel-UHPFRC composite deck system, consisting of upper thin reinforced UHPFRC slab, hot rolled sections as longitudinal ribs, and steel strips as transversal reinforcement, is proposed originally in this paper. Considered as more economic and sustainable structure, the new composite deck is a promising alternative to traditional orthotropic steel deck (OSD) in long-span bridge. In this context, due to the relatively thin UHPFRC layer, the punching behavior of new composite deck becomes one of the dominant issues, which determines the spacing of steel trips. Hence, this paper presents the results of punching tests on 12 new composite deck slabs with various spacing of steel strips. All slabs failed in punching-flexure mode with a clearly delimited punching cone and significant flexural cracks on tensile surface. Moreover, the presence of steel strips can increase the punching shear resistance and flatten the inclination of critical shear cracks.
Measures to Control Vortex-induced Vibration for Shangba Branch Channel Bridge in Nanjing
Authors: Han Dazhang , Hua Xin , Ding Lei , Ma Rujin
Published: November 2022

An all-steel cable-stayed bridge with steel towers, steel box girders and cables for a main span of 500m is rarely seen at home and abroad. Due to the low damping ratio of all-steel structure, wind- induced vibration is likely to occur, especially for a single column steel tower, and twin-box girder with a total width of 54.4m is also more susceptible to vortex-induced vibration. In this paper, the aerodynamic shape of the main girder is optimized by sectional model wind tunnel test, and an aerodynamic configuration as the combination of wind fin plate and wind baffle plate to control the vortex-induced vibration (VIV) has been found. The damping effect of the main girder was also studied. The VIV and buffeting performance of the freestanding steel tower and its combined system with tower crane and construction platform were also studied.
Tendon Distribution Optimization Method of Prestressed Concrete Bridges Based on Consistent Safety Degree of Stress Index
Authors: Wang Tianhu , Xu Dong , Wang Shengbin
Published: November 2022

The traditional tendon distribution method of prestressed concrete bridges is mainly based on trial calculation. The existing optimization research of structure and tendon distribution mostly takes the least material consumption or total economy as the optimization goal, but the stress of the structure may not be reasonable. Therefore, considering the rationality of structural stress, the optimization method has a large research space. This paper puts forward the tendon distribution optimization method for the prestressed concrete bridge. This method takes the principle that the safety degree of stress indexes at different positions of the whole bridge is as consistent as possible. On the premise of meeting the codes and construction feasibility, this method realizes the optimization of the amount of prestressed steel tendons in the bridge. Finally, a three-span continuous bridge is used as the optimization example to verify the rationality and feasibility of the method.
Numerical Analysis of Flexural Behaviour of High Strength I-Shape Steel Composite Girders with Corrugated Webs
Authors: Duan Lan , Ren Weihua , Cheng Feng , Wang Chun-Sheng
Published: November 2022

With the high out-of-plane stiffness and shear buckling strength, the number of stiffeners and the thickness of the web can be reduced when using corrugated webs in composite girders. The finite element model is established according to the existing experimental results. The flexural behaviour of I-shape steel composite girders with the corrugated web was investigated by numerical analysis. From the numerical results, the flexural behaviour of I-shape steel composite girders can be improved by increasing the strength of materials. The concrete slab grade range of C50 to C60 was recommended to ensure full use of concrete and high strength steel material properties. The high strength steel grade with nominal yielding strength between 420MPa and 460MPa were suggested for bottom flange with priority, while steel grade no less than Q345 was suggested for corrugated web to avoid the safety risks caused by the premature reaching of the yield strength of the web.
Numerical Simulation of Longitudinal Shear Behavior of High Strength Steel and Concrete Composite Girders
Authors: Duan Lan , Xin Yangfan , Dawa Zhaxi , Wang Chunsheng
Published: November 2022

Longitudinal shear failure is a typical failure mode for composite girders. Based on experimental study, the finite element model was calibrated and numerical studies were carried out to analysis the longitudinal shear behaviour of high strength steel and concrete composite girders. It was analysed the effect of transverse reinforcement ratio, concrete strength, and steel grade on the longitudinal shear behaviour of high strength steel and concrete composite girders. Based on the current specifications, the transverse reinforcement area and longitudinal shear strength of the test girder were verified. Learn from the analysis results, the concrete strength grade no less than C60 was suggested with priority for concrete slab, for composite girders using steel with nominal yielding strengthen above 420 MPa. To prevent the longitudinal shear failure for the high strength steel and concrete composite girders, the transverse reinforcement ratio no less than 1,18% was suggested.
Vibration Control of Simply Supported Beam Bridges Equipped with an Underdeck Adaptive Tensioning System
Authors: Reksowardojo Arka P. , Senatore Gennaro , Blandini Lucio , Bischoff Manfred
Published: November 2022

External post-tensioning offers significant potential to improve the load-bearing performance of bridges. However, typical external post-tensioning systems are effective for a specific load case. This work investigates the application of an external adaptive tensioning (EAT) system for high-speed railway (HSR) bridges. The design of HSR bridges involves strict acceleration constraints, which typically results in oversizing. The EAT system comprises under-deck cables deviated by linear actuators, which enable controlling the bending moment as the load changes. Simulations are carried out on simply supported beam bridges. Results show that active control through the EAT system allows satisfying vertical acceleration limits for mid-span HSR bridges, which cannot be met otherwise without incurring a weight penalty. In addition, the cyclic stress range is significantly reduced showing the potential for fatigue-life extension.
Experimental Study on Tension Mechanisms of UHPC Link Slab
Authors: Briseghella Bruno , Lin Jianhui , Xue Junqing , Pan Xiangfeng , Nuti Camillo
Published: November 2022

The ultra-high performance concrete (UHPC) link slab has been proposed to provide a suitable solution to the cracking problem of conventional reinforced concrete (RC) link slab. This paper presents an experimental study on the tension mechanisms of UHPC link slab under monotonic tension loads. The experimental results of load-displacement curves, crack development and strains of UHPC link slab were investigated and compared with those of RC link slab. It can be found that in the elastic phase, the tension stiffness and ultimate loads of the UHPC link slab were respectively

2.6 and 2.4 times those of the RC link slab. Compared with the RC link slab, the number of cracks on the top surface of the UHPC link slab was larger, but the average crack width was significantly smaller. The concrete and reinforcement strains of UHPC link slab were smaller than those of RC link slab.
Review on Flow Characteristic and Pumpability Prediction of Pumping Concrete
Authors: Luo Chao , Yan Zhifa , Lin Huiwen , Chen Rui , Liu Jianzhong , Han Fangyu , Li Hongtao , Ruan Jing , Haifeng Lin , Junping Dai , Feng Zhao
Published: November 2022

Pumping is the most commonly used construction method for modern concrete transportation and pouring. This paper summarizes the theoretical and experimental research results on the flow behavior characteristics and pumpability prediction of pumped concrete. The formation mechanism of lubrication layer based on shear induced particle migration theory is introduced, and the distribution of concrete shear rate and flow rate in the pipeline is analysed. This paper discussed three prediction methods of concrete pumpability, including empirical judgment, coil test and pumping resistance calculation. Thus, the cognition of concrete pumping process can be improved and reference for engineering and technical personnel in pumping construction can also be provided.
Investigation on the Unsteady Aerodynamic Force on a 3:2 Rectangular Section under Accelerating Airflow
Authors: Chen Xiuyu , Zhu Ledong , Tan Zhongxu
Published: November 2022

Unsteady characteristics of aerodynamic force and wind-induced pressure on a 3:2 rectangular section under accelerating airflow are investigated through wind tunnel experiments. Three aerodynamic coefficients, drag coefficient Cd(t), RMS of lift coefficient Clrms(t), Strouhal number of the rectangular section in the accelerating airflow with or without initial velocity are compared with those of the steady flow. Results show that in the cases of airflow accelerated from the static state, significant unsteady feature appears in all three aerodynamic coefficients, 𝐶𝐶𝑑𝑑(𝑡𝑡) and

Clrms(t) decreases and St number increases in the early accelerating stage. For accelerating airflow with an initial velocity, the three aerodynamic characteristics fit well with steady flow values, indicating negligible impact on any of these variables.
Numerical Simulation Analysis of the Connection Structure Between the Pier and Pile Cap of Precast Concrete Bridge Piers
Authors: Li Wenjun , Zhou Qiang , Ma Rujin , Li Yongjun , Liu Siwei
Published: November 2022

The precast concrete bridge pier in Ganzhou City, Jiangxi Province, China, was used as the research object to compare the longitudinal and transverse force differences of the bridge pier and further analyze the force characteristics of the bridge pier connection structure. The refined nonlinear finite element model with the load direction and axial pressure ratio as the variation parameters was established to analyze the horizontal force-displacement curve, anchor force, shear force of notched perfobond connector, strain distribution of steel jacket and notched perfobond connector-concrete relative slip. The results show that the concrete damage, anchor bolt action, strain distribution of steel jacket and notched perfobond connector-concrete relative slip are different in the longitudinal and transverse direction of the bridge pier. The bearing capacity of large axial pressure piers is larger than that of small axial pressure piers. The compression side damage of precast piers occurs at the concrete interface above the connection device. The shear force of outer notched perfobond connector is less than that of inner notched perfobond connector.
Numerical Analysis of Top-Down Construction Method of High-Rise Buildings and its Effects on Substructures with their Corresponding Heights
Authors: Abualghethe Dhyaa A. H. , Baogang Mu
Published: November 2022

The Top-Down construction method has been used widely in urban areas, particularly in high-rise buildings with basements. This paper presents the Nanjing Jinmao Plaza II Tower in Nanjing-China as a case study, which consists of 68 floors with a height of 283.6 m and five basements with a depth of 27.5 m. A numerical finite element simulation in PLAXIS 3D was performed to analyze the construction of soil excavation and basement structure and their corresponding heights. The study concluded that the effect of adding floors to the superstructure had little effect on the underground excavation process. Likewise, the condition of column piles is in different stages of construction. In view of that, this paper has analyzed and summarized construction guidelines for the top-down construction method to ensure safety, optimize design, and provide recommendations for this promising construction technique.
Structural Detailing of Bridges, Making Use of the Brim Methodology (Bridge Information Modeling), through the Creation of Parametric Models and As-Build Plans
Authors: Rojas Alvaro , Valenzuela Matias , Peña Álvaro
Published: November 2022

Within a project related to the area of bridges, we work with different tools and between this information is usually managed through the use of CAD drawings made basically in 2D.

Today, a new concept of BIM applied to bridges called Bridge Information Modeling (BrIM), which well implies being a methodology with different uses and being the solution in helping the different parties to work more collaboratively, effectively and simultaneously.

This paper presents the experience of applying one of these uses in the phase of analysis and structural diagnosis of ten bridges in Chile, which demonstrates that this technology becomes a valuable tool for information management through the virtual model worked between the different parties involved in the maintenance and operation of a project.
Moveable Facade Elements for Sustainable High-rise Buildings
Authors: Zhang Yangwen , Wulff Wulf , Bleicher Achim , Wernicke Laurenz , Schauer Thomas , Engelmann Michael
Published: November 2022

This paper presents a sustainable semi-active distributed-Multiple Tuned Facade Damping (d-MTFD) system that utilizes the existing mass of the Double-Skin Facade's outer skin as damping mass to mitigate structural vibrations caused by wind excitation. Based on this concept, a prototype with one full-scale parallel moveable facade element has been developed, built, and validated. A stepper motor working together with its connected energy harvesting circuit is innovatively applied as an adjustable electrical damper and simultaneously as an energy harvester. Its feasibility has been proven through experiments using Hardware-in-the-Loop (HiL) simulations. An energy harvesting efficiency of 75% was achieved by using a two-stage power converter as the energy harvesting circuit. The self-sufficiency of the semi-active d-MTFD system was achieved.
Next-Generation Modular Expansion Joints for Bridges – “Smart” And Easily Replaceable in Order to Minimise Life-Cycle Costs
Authors: Savioz Pascal , Shen Golden , Hoffmann Simon
Published: November 2022

This paper about bridge expansion joints of the modular type includes an introduction to the development of this type of expansion joint since its invention almost six decades ago. It also provides an insight into the current state-of-the-art technology in this field, including such innovations as the option of pre-equipping the joints with sensors for easy integration in a bridge’s automated monitoring system – thereby making the joints “smart” – and the option of designing the joints to be easily replaceable when the need arises – thereby minimising the associated costs and disruption to traffic. Considering the huge contribution of maintenance and replacement works to the life-cycle costs of a bridge’s expansion joints, the use of such options – combined with the design optimisations resulting from these decades of ongoing development work – enables the long- term costs associated with a bridge’s expansion joints to be greatly reduced.
Research on Sectional Optimization Design of Fabricated Bent Cap of Urban Viaduct
Authors: Dong Hao , Wu Huishan
Published: November 2022

With the rapid development of national transportation infrastructure, viaduct has been widely used in the construction of urban expressway. The prefabricated bridge scheme has significant advantages in such areas as traffic organization, construction period and environmental protection. Taking a project under construction in Jiangsu as an example, this paper compares and analyzes the impact of various bent cap segmental forms on the project construction, and provides for optimization design schemes, with the aim of providing reference for the design of Urban Viaduct of similar type in the future.
A New Method for Calculating Bridge Influence Surface
Authors: Wu Haibing , He Wei , Deng Lu
Published: November 2022

Bridge influence surface (BIS), which reflects the relationship between the bridge response and the unit load moving on the bridge, has been commonly used in bridge weigh-in-motion, bridge damage detection, etc. Generally, the BIS can be obtained by interpolating bridge influence lines (BILs) at different lateral positions. In field tests, the BILs are usually extracted from the bridge response induced by a moving calibration vehicle with known axle loads. However, when taking the axle loads of the calibration vehicle into calculation, the impacts of the transverse distance between coaxial wheels and the unbalance of the coaxial wheel loads are ignored. Hence, errors may be brought to the calculated BIL and then propagated to the BIS. To remove these impacts, a new BIS calculation method, which takes the load of each wheel rather than each axle into calculation, is proposed in this research. Numerical simulation shows that the BIS can be successfully estimated by this method.
Experimental Verification of a Novel Accelerometer Intended for Structural Health Monitoring of Bridges
Authors: Komarizadehasl Seyedmilad , Alahmad Ahmad , Lozano-Galant Jose A. , Torralba Victor , Ramos Gonzalo , Turmo José
Published: November 2022

Bridges can be considered one of the most critical infrastructures of any country. Subsequently, their health state assessment is of great importance. However, durable monitoring of bridges can be highly costly and time-consuming. In addition, the current Structural Health Monitoring applications are only applicable to individual structures with a high budget for their health assessment. For a long-term economic evaluation of bridges, low-cost sensors are currently being developed for SHM applications. However, their resolution and accuracy are not yet suitable for structural system identifications. For that, a novel accelerometer based on Arduino technology is introduced in this work. Experiments show that this accelerometer has a better resolution. Illustrated test results of this paper on a frequency range of 0.5 to 8 Hz validate the performance of the proposed accelerometer.
Inspection Information Preprocessing for Regional Bridge Condition Assessment
Authors: Zhang Chenhong , Xia Ye , Sun Limin
Published: November 2022

Condition assessment of bridges on a regional level can provide an accurate assessment of bridges lack of inspection data and reliable prediction of structural condition for regional bridges. The core work of regional bridge condition assessment (RBCA) is the establishment of regional deterioration models, which requires a large amount of historical health data of bridges provided by inspection reports throughout service history. An inspection information pre-processing framework is proposed in this study, including data extraction, integration, and storage. The proposed framework can greatly reduce the amount of time and work invested in the information gathering process, providing richer data support for (RBCA). The framework is applied to 2 sets of inspection reports of 2 different highway bridge networks in Shandong.
On the Benefit of Including Modal Strains in FE Model Updating for Damage Assessment
Authors: Yang Wei , Peng Chongmei , Sun Limin
Published: November 2022

FE model updating has mostly been performed relying upon natural frequencies and mode shapes. These modal parameters only provide global information about the structure, which leads to important uncertainties. The recent development of fiber optic strain sensors has made it possible to include modal strains in FE model updating. In this paper, it is investigated how including modal strains in FE model updating allows complementing the global information on natural frequencies and mode shapes by the local information in modal strains. Including modal strains can be of major benefit for identification of local damage. With the additional information obtained using modal strains, local uncertainties in FE model updating can be effectively reduced. The benefit of including modal strains in FE model updating is illustrated using modal data from numerical simulations on a reinforced concrete (RC) beam.
Corrosion Suppression Effect of Bridge Cables Using Environmental Isolation Paint
Authors: Miyachi Kazuhiro , Kinoshita Koji , Takebuchi Toshio
Published: November 2022

This study examined the corrosion suppression effect of bridge cables using environmental isolation paint. The strand rope which is also used for the main cables and hanger ropes of short/middle-span bridges is used for the specimens and compared the presence or absence of the paint on the surface. The accelerated corrosion test was conducted by the salt spray test method to examine corrosion suppression effect. As a result, the rust was confirmed on the appearance of the unpainted specimens, but no rust was confirmed on the painted specimens. Furthermore, the corrosion state from surface to inside was confirmed by EPMA analysis on the cross-section. The distribution of oxygen and chloride were large, and the occurrence of corrosion was confirmed in the unpainted specimens. On the other hand, no corrosion was confirmed on the rope surface in the painted specimens.
Regional Bridge Data Extraction and Integration Based on Historical Detection Reports
Authors: Zhang Wenwu , Zhang Chenhong , Xin Gongfeng , Xu ChuanChang
Published: November 2022

This study firstly analyses the information source of individual bridge condition evaluation, then expand the analysis from individual bridge to regional bridge-group evaluation, and formulate integration rules for regional inspection, monitoring, traffic volume, and drawings. The integrated data from multi-source information are stored and expressed in the logical form of "route-bridge- component". After data cleaning, a road network database is established, the integrated data is mined for features, and then a comprehensive network level evaluation of regional bridge groups is carried out. The proposed information integration and data mining method and application model can effectively reveal the common characteristics and degradation laws of bridge groups in the road network and can be used for regional bridge network-level assessment.
Direct Shear: A Mechanism that is Often Ignored and Rarely Studied
Authors: Xu Dong , Jin Yongxue , Liu Huifen
Published: November 2022

The defect of excessive lone time deflection of prestressed concrete bridges has been researching for decades. Many researches focused on reducing the long time dead-load deflection of the completed bridge. Another research method is trial calculation, which includes adjusting prestress loss, structural stiffness, or modifying the creep model to fit the deflection changes of the real bridge. Nevertheless, there is still a lack of recognized solution. In this paper, with the continuous research on the excessive long time deflection of PC girder bridges in the Department of Bridge Engineering at Tongji University, another kind of shear caused excessive defection is proposed, which is also a mechanism that is often ignored and rarely studied: direct shear. The transverse analysis method of the box section and its influence on longitudinal direct shear are presented in detail. Finally, some research and design suggestions are put forward.
Analysis on Segmental Deck Replacement Plan for Large-Span Network Arch Bridge
Authors: Fu Huiyang , Su Qingtian , Zheng Shixi , Zhang Yong
Published: November 2022

As a long-span network suspender arch bridge, the main girder of Qilu Yellow River Bridge was designed as steel-concrete composite structure, and the concrete deck was designed as replaceable components due to the possible severe local damage caused by the direct vehicle load. In this paper, different segmental replacement plans were put forward according to the structural characteristics, and an integral mixed finite element (FE) model was established based on the 420m main span in order to study the mechanical performance of this bridge in the process of deck replacement. The effect of variable replacement lengths and positions on the structural response, in both longitudinal and transverse directions was figured out. The analysis results show that all the deck replacement plans discussed in this paper are feasible, and different demolition methods affect the stress change amplitude of the structure in different way, of which the lateral change of replacement methods has a more obvious impact on the structure.
Seismic Vulnerability Study of Precast Segmental Piers with Bonded Tendons
Authors: Zhuo Saiyang , Tong Teng , Liu Zhao , Wang Xu , Zhuo Weiding
Published: November 2022

The widely applications of precast segmental bridge piers in high-seismicity areas are hindered for their insufficient capacities of energy dissipation. In this study, precast segmental piers’ seismic behaviours were investigated, focusing on the connection of “grouted sleeves/bonded tendons”. Four piers were cyclically loaded, of one cast-in-place pier, one precast segmental pier, and two prestressed precast segmental piers. Experimental results showed that bonded tendons apparently enhanced the pier’s lateral strength, ductility, energy dissipation capacity and reducing residual drift. Of particular, bonded tendons prevented the shear-induced slip between the shaft and footing segments. Furthermore, seismic vulnerability assessments of the bridge piers are obtained in terms of fragility curves. Residual drift is adopted to define the limit states. It is suggested that bonded tendons could significantly ameliorate the fragility curves of precast segmental piers.
Seismic Fragility of Double-Deck Curved Girder Bridge Based on Artificial Neural Network and Lasso-Logistic Regression
Authors: Guo Weizuo , Wang Kehai
Published: November 2022

Double-deck curved girder bridges are frequently used to satisfy the demands of traffic lines to accomplish quick ascents. However, damage to this type of bridge has a significant impact on the entire transportation network. Therefore, it is necessary to study the seismic fragility of this type of bridge. The seismic demand model and the multidimensional seismic fragility model of a double-deck curved girder bridge are established using the artificial neural network and the Lasso- logistic regression method. The following conclusions are drawn: 1) The gap value has a significant impact on the fragility of the bearing and limit device. 2) The impact of the friction coefficient of bearing and concrete strength on component fragility reduces as the damage level increases. 3) The ground motion intensity is the most important factor in pier damage.
Damping of long-span suspension bridges with damped outriggers
Authors: Liu Zhanhang , Chen Lin , Sun Limin
Published: November 2022

Long-span suspension bridges are vulnerable to vortex-induced vibrations (VIVs), e.g., the Humen Bridge and the Xihoumen Bridge in China. This study focuses on a novel strategy by using damped outriggers to control rotations of bridge deck at the junction points between the girder and a bridge tower or pier. A simplified model of a suspension bridge with damped outriggers is used for damping analysis. Considering practical parameter ranges, the maximal damping ratio provided by one damped outrigger to a specific mode is about 1.0%. Influences of bridge boundary conditions, installation position of damped outriggers, and interaction between multiple damped outriggers are studied. When multiple damped outriggers are installed, the damping effects of multiple modes can be further improved. It is shown that damped outriggers are effective in suppressing multimode vibrations of long-span suspension bridges.
Influence of Time-Varying Mean Winds on the Nonlinear Buffeting Responses of a Super Long-Span Suspension Bridge
Authors: Zhou Rui , Zhou Haijun , Ge Yaojun , Yang Yongxin
Published: November 2022

The cosine function and two modulation functions are separately selected to generate the time- varying mean wind and fluctuating wind speed, and their effects on nonlinear buffeting responses of a super long-span suspension bridge were investigated in this paper. Firstly, two non-stationary wind speeds models were validated by the classical power spectrum density, and could effectively simulate the non-stationary characteristics. Secondly, the time histories and RMS values of three displacement responses of the bridge deck under two non-stationary wind speeds with three different values of 𝛾𝛾 and 𝜃𝜃 were compared, respectively. Results show that the torsional and lateral displacement responses under the non-uniform modulation function are larger than those under the uniform modulation function. Moreover, the RMS values in three displacement responses of the deck gradually become larger with the increase of 𝛾𝛾 or the decrease of 𝜃𝜃.
Experimental study on the influence of gust-wind on a high-speed railway train-viaduct system
Authors: Zou Simin , He Xuhui
Published: November 2022

As the high-speed railway emerges in Eurasia, a comprehensive understanding of the aerodynamic problems – particularly extreme wind events – is vital to the success of the safety, operational efficiency, and transportation industry. Such knowledge of the effect of extreme wind on the train and bridge system has been hindered by a lack of available field test data. In light of limited field measured data to arrive at a consensus on quantifying key parameters characterizing the non-stationarity winds, accuracy associated with wind velocities is carried out using wind tunnel experimental approaches in this study. Compared with atmospheric boundary layer winds, which are customarily treated as stationary, winds associated with gust-fronts originating from a thunderstorm/downburst/tornado exhibit rapid changes during a short period which changes in direction may accompany. To realistically capture the characteristics of gust-front winds and their attendant load effect, a new gust-wind generator was presented, built in the CSU wind tunnel. Under a condition of the combined operation between a gust-wind generator and wind tunnel, the gust-front wind characteristics and effects on the train-bridge system were analyzed.
Investigation on Extreme Temperature Gradient Action of Composite Girder Bridges Considering Regional Difference
Authors: Liu Jiang , Liu Yongjian , Ma Zhiyuan , Lyu Yi
Published: November 2022

To reach an accurate calculation of the effect of composite girder bridges under extreme temperature gradient action, long-term temperature measurements and finite element simulations were performed on a composite girder segment in Huangnan Prefecture, Qinghai Province for more than one year. By setting the maximum thermal self-stress and secondary stress as indexes and considering different sunshine conditions between interior and exterior girders webs of composite girder bridges, 3 temperature gradient patterns were established for multi- girder bridges. Based on the long-term historical meteorological data collected from 839 weather stations in China, a “layer-by-layer drawing method” was put forward to the isoline map of extreme temperature gradient values. Compared with the current specification, the temperature action values provided are more suitable for the Limit State Design Method.