Hasil untuk "Bridge engineering"

Elise C. Gallois, Arianna Salili‐James, Sanson T. S. Poon et al.

Abstract The Anthropocene presents significant challenges for global biodiversity, public health and ecosystem stability. The wealth of publicly available near‐real‐time ecology and climate data can be used to monitor these challenges and allow practitioners to develop mitigation strategies. There is untapped potential to apply large language models (LLMs) to quantitative ecological and environmental datasets, enabling researchers and practitioners to use natural language queries to transform ecological observations into actionable insights for both conservation action and communication of results to diverse audiences. Advances in artificial intelligence (AI), and particularly in LLMs, offer emerging opportunities to address these challenges. LLMs are increasingly proficient at identifying patterns and semantic relationships within textual data and are highly customisable. Accessible AI tools can facilitate communication across research and policy sectors. Here, we present a roadmap for designing and implementing multi‐modal LLMs to answer ecological research questions. To build robust ‘virtual quantitative assistants’ capable of fast‐tracking data interpretation, we advocate for strategic planning, data stewardship practices, careful prompt engineering and model evaluation as key steps in the LLM development process. We discuss potential use‐case examples that apply the LangChain framework to analyse citizen science data. Using our LLM roadmap, we highlight the importance of iterative and strategic prompt engineering and agent selection, in addition to iteratively evaluating model output. As LLM software continues to evolve, its integration into ecological and environmental research can empower ecologists with purpose‐built tools that bridge the gap between data collection and actionable solutions.

Wenya Yuan, Baoxin Jia, Zhiyang Zhou et al.

Abstract In this work, through the field monitoring and vibration signal analysis, we proposed a multi-parameters vibration assessment method for ground vibration induced by high-speed railway trains. And also, based on the assessment results, we developed a prediction model of z-vibration level, which is characterized with multiple piers vibration source and exactly applicable to the ground vibration prediction under the high-speed railway bridges. Firstly, by carrying out the field monitoring test, the ground vibration signals induced by high-speed railway trains were collected, with the ground vibration characteristics and influencing factors under the high-speed railway bridge are analyzed. Secondly, the ground vibration assessment was conducted by Peak Particle Velocity (PPV), Peak Particle Acceleration(PPA) and the z-Vibration Level (VL Z ) respectively, and on this basis, we proposed a multi-parameters vibration assessment method for ground vibration around the high-speed railways. Then, according to the assessment results, based on the vibration attenuation model under railway traffic load effect and the superposition feature of multi-piers vibration sources under high-speed railway bridges, we developed a ground vibration attenuation prediction model of VL Z , which is characterized with multi-piers vibration sources and exactly applicable to the ground vibration prediction under the high-speed railway bridges. Besides, an application example of environment vibration prediction was given, and the site selection distance threshold away from the high-speed railways of different types of environmental vibration function areas were determined. The study showed that the proposed multi-parameters vibration assessment method was so comprehensive that it could take the vibration safety of building structures, human perception comfort and environmental vibration limit all into consideration. And meanwhile, by comparing the predicted VL Z with the field monitored data and the empirical formula calculated value, the developed ground vibration attenuation prediction model was tested with better prediction accuracy and wider effective prediction range. As a result, the study was expected to provide a theoretical reference for the construction of ground vibration assessment system around high-speed railways, with potential engineering application value in ground vibration attenuation prediction and site selection of building structures under the high-speed railway bridges.

M. S. Mirmoosa, T. Setälä, A. Norrman

Modulating macroscopic parameters of materials in time offers innovative avenues for manipulating electromagnetic waves. Due to such enticing prospects, the general research subject of time-varying systems is expanding today in different branches of electromagnetism and optics. However, compared with the research efforts and progresses that have taken place in the realm of classical electrodynamics, the quantum aspects of this emerging subject have been less explored. Here, through the lens of quantum optics, we study the scattering of electromagnetic fields from an isotropic and nondispersive material with a suddenly changing refractive index, creating a time interface. We revisit the transformation of the bosonic mode operators and corresponding quantum states due to this interface, governed by the two-mode squeeze operator. Building on this foundation, at the core of the investigation, our analysis focuses on the quantum state engineering and photon statistics of the scattered light. Notably, such an analysis reveals and connects various quantum optical phenomena and opportunities arising from the time interface, including photon-pair production and destruction, photon bunching and antibunching, vacuum generation, quantum state discrimination, and quantum state freezing. To bridge theory and experiment, we propose a possible circuit quantum electrodynamics approach for validating our theoretical predictions. We hope that our work inspires experimental investigations of such quantum state engineering and photon statistics phenomena, as well as further quantum optical explorations of electromagnetic field interaction with photonic time crystals or with dispersive time-varying materials.

Chuheng Zhong, Dongping Wang, Lijuan Zhang et al.

Abstract This study aims to enhance the durability, cost-effectiveness, and sustainability of recycled fine aggregate concrete (RFAC) subjected to the combined effects of wet-dry cycles and sulfate erosion. Dry–wet cycle tests were conducted in RFAC with different admixtures of biotite metakaolin (MK) and 15% fly ash (FA) mix (M) under 5% sulfate erosion environment. The effect of 0%, 30%, 60% and 90% recycled fine aggregate (RFA) replacement of natural fine aggregate on mass loss, cubic compressive strength, relative dynamic modulus test of RFAC, damage modeling and prediction of damage life of concrete were investigated. The results showed that the concrete cubic compressive strength and relative dynamic modulus were optimal for recycled concrete at 15% MK biotite dosing and 60% RFA substitution, and its maximum service life was accurately predicted to be about 578 cycles under 5% sulfate dry–wet cycling using Weibull function model. This study is pioneering in addressing the durability of RFAC under sulfate attack combined with wet-dry cycling, employing a novel approach of incorporating MK and FA into RFAC. The findings highlight the practical application potential for using MK and FA in RFAC to produce durable and sustainable construction materials, particularly in sulfate-exposed environments. This research addresses a critical challenge in the construction industry, providing valuable insights for developing more durable and eco-friendly construction materials and contributing to long-term sustainability goals.

Xiaoquan Guo, Shigong Zhang, Changjian Zhao

Improving the prefabrication and assembly level of composited beams with corrugated steel web is key to promoting their application in bridge engineering for medium-span bridges. This paper first derives the principle of 'vertical composite force invariance' unique to composite beams with corrugated steel webs, and validates this principle using finite element structural models. Based on this, four new types of prefabricated and assembled continuous composite beams with corrugated steel webs are developed, and their respective characteristics are analyzed to provide references for other engineering practices.

Xiaoxia Zhao, Dajiang Geng, Zhiqiang Cheng et al.

Based on the advantages of the silicone graphene composite thermal insulation board, it was used to replace traditional plywood in the external wall formwork system, and the active embedded steel wire knot form in silicone graphene composite thermal insulation structure integrated system was designed. Firstly, the theoretical model of steel wire drawing resistance was established by theoretical analysis method, and the rationality of the theoretical model was verified by combining relevant experimental data. The relationship between multiple variables and steel wire pull-out resistance was analyzed. Then, combined with the theory of wind pressure strength of the exterior wall of a building structure, the layout form and the corresponding number of embedded steel wires of thermal insulation board under different building heights were analyzed. Finally, the silicone graphene composite thermal insulation board and ordinary plywood were compared and analyzed from the force of perspective of external wall formwork. The results showed that the pull-out resistance of steel wire was directly proportional to the diameter of steel wire, embedded depth, and embedded deflection angle. With the increase of building height, the number of steel wires to be arranged also increased. When the thickness of the silicone graphene composite thermal insulation board is not less than 80 mm, the anti-deformation effect is close to that of the ordinary plywood, which can meet the construction requirements of the external wall formwork. It can ensure the energy conservation and thermal insulation of the external wall, integrate the building’s exterior wall and thermal insulation structure of the building, and achieve the purpose of exemption from formwork removal.

Wenqing Wu, Wenkai Liu, Jun Hu et al.

AbstractAs a landmark in China’s hydraulic engineering history, the Central Route of the South–North Water Diversion Project (SNWD-CR) plays a major role in alleviating severe water shortages in Northern China. Existing InSAR monitoring of the SNWD-CR based on one-dimensional viewing geometry and Sentinel-1 imaging is insufficient for a comprehensive assessment of deformation causes. Moreover, the poor geocoding accuracy hampers the previous interpretation of the estimated deformations. Here we carry out comprehensive two-dimensional deformation analyses over the head of the SNWD-CR by integrating the multitemporal PS/DS InSAR and the stress–strain model, where the well-designed topography and geocoded error correction can help to identify the causes of deformation. We apply our strategy to ascending and descending TerraSAR-X meter-resolution datasets acquired from June 2020 to February 2021. Geocoding errors in both ascending and descending orbits are corrected, and the relationship between topography error and horizontal positioning error is discussed. The multi-data fusion results reveal insignificant deformations in the east–west direction except for a makeshift rigid-frame bridge, whereas the vertical deformation field shows two uplifts and a subsidence area in the narrow canal with a maximum rate of 23 mm/y, which are likely to be related to rainfall and water diversion pressure. Furthermore, the combination of the external DEM and topographic residual offers the chance to reconstruct the high-accuracy DEM.

Lin Zhang, Yuangui Pan, Kezhu Chen et al.

Several engineering practices have shown that the excavation of shallow-buried tunnels beneath major roads, as well as the selection of appropriate engineering measures and construction methods, has a significant impact on road surface settlement. Therefore, field monitoring and numerical simulation are adopted in this study to analyze the effect of the cross diaphragm (CRD) excavation method on surface settlement for the under-construction Yüan 1 railroad tunnel. The findings show that during the excavation of the four divisions of the CRD excavation method for shallow-buried tunnels, the amount of surface settlement caused by the excavation of part 1 accounts for 40% of the total surface settlement, followed by the excavation of part 3, accounting for 30% of the total surface settlement, and the difference between the excavation of parts 2 and 4 is insignificant, with part 2 slightly larger than part 4. The main influence of the CRD method on surface settlement for shallow-buried tunnels is 0.64–0.86 times the cavity diameter from the tunnel median, within which the final surface settlement caused by excavation is within the same horizontal range, and beyond which the surface settlement is prone to dramatically decline. By applying advanced grouting and adjusting the construction method of CRD based on the monitoring data, the effect of the CRD excavation method on surface settlement can be controlled.

Yuan Jing, Xu Zhang, Yongjun Zhou et al.

The dynamic response of a prestressed concrete box girder bridge under the impact of an over-height vehicle is studied using the numerical simulation method. The finite element analysis software LS-DYNA is used to simulate the collision between the bridge superstructure and an over-height truck. Further, a parametric analysis is carried out to investigate the influence of six factors, i.e., girder configuration, vehicle speed, vehicle mass, impact angle, concrete strength and strand prestress, on both local damage and overall performance of the bridge. The numerical analysis results show that the girder configuration, vehicle speed, vehicle mass and impact angle have obvious effects on both local damage and the overall behavior of the PC box girder bridge. Whereas, the concrete strength and strand prestress only have a certain effect on the local damage at the impact area with very limited influence on the overall behavior of the bridge. In addition, based on the results obtained from the numerical simulation and parametric analysis, a formula for predicting the peak and average impact force of the prestressed concrete box girder bridge under the over-height vehicle impact is developed. The proposed impact force formula comprehensively accounts for the influence of the vehicle speed, vehicle mass and impact angle and can accurately predict the impact force generated under different working conditions, which confirms the promising prospect of the proposed formula in practical applications.

Marcin Chybiński, Łukasz Polus, Maciej Szumigała

This paper presents a review of composite structures in which aluminium alloys are used. Current trends in the research of composite structures with aluminium girders and their possible applications in structural engineering were shown. In the presented solutions, advantageous properties of aluminium alloys were exploited, such as high strength-to-weight ratio, corrosion resistance and recyclability. The authors demonstrated the structural behaviour of aluminium-concrete and aluminiumtimber composite beams based on their own tests as well as investigations presented in the literature. Furthermore, aluminium-concrete composite columns, a composite mullion made of an aluminium alloy and timber, and a military bridge consisting of aluminium truss components, a stay-in-place-form, reinforcement and concrete were presented. In addition to the description of the structural elements, the main conclusions from their experimental, theoretical and numerical analyses were also demonstrated in this paper. The connection of aluminium girders with concrete or timber slabs provided for the increase of the load-bearing capacity and stiffness, and it eliminated the problem of local buckling in girder flanges and lateral-torsional buckling of girders in the analysed solutions.

Jinlin A, Chaoyang Xie, Fayuan Wei

The natural aging of silicone foam materials leads to a decline in their mechanical properties, which, in turn, affects the structural response of systems incorporating these materials. This study investigates the accelerated aging of silicone foam through stress relaxation tests, compression set tests, and uniaxial compression tests. By using the constitutive relationship as a bridge, a connection between stress relaxation and compression set is established, forming a predictive model for structural response. This model is validated against experimental results through finite element analysis. The high degree of accuracy between the predictive model and the experimental outcomes confirms its suitability for engineering applications.

Michelle L Bell

Environmental Research: Health is a new open access, interdisciplinary journal devoted to addressing important global challenges at the interface of the environment and health in ways that bridge scientific progress and assessment with efforts relating to impact and future risks, resilience, mitigation, adaptation, security and solutions in the broadest sense. While progress has been made in many areas of environmental health, many problems remain and are in fact rising, with increasing threats from climate change and growing disparities in the health burdens of environmental conditions. Although many disciplinary and some broader journals exist, Environmental Research: Health functions at the intersection of science and solutions, which necessitates contributions from multiple disciplines, often working collaboratively, to provide science to better inform decisions from the local to global levels. The journal welcomes contributions from all research methodologies, including qualitative, quantitative, experimental, theoretical and applied approaches, including work on exposure assessment, implementation studies, policy analysis, and health assessment. Through open access, all science published in the journal will be made available free of charge to everyone. The inaugural Editorial Board spans experts from many fields including medicine, epidemiology, architecture, environmental engineering, statistics, and more. Environmental Research: Health aims to facilitate high caliber scientific evidence on how environmental conditions can harm or improve health to allow decision-makers from community groups to national and international leaders to make the best choices to improve health and the environment.

Yuzhou Xiang, Zhikai Zeng, Yangjun Xiang et al.

Abstract Geo-materials may present varying mechanical properties under different stress paths, especially for tunnel excavation, which is typically characterized by the decreased radial stress and increased axial stress during the complex loading and unloading process. This study carried out a comparative analysis between the loading and unloading model testing, which was then combined with PFC2D simulation, aiming to reveal the fracture propagation pattern, microscopic stress and force chain distribution of the rock mass surrounding the tunnel. Comparisons of extents and development of tensile strain between loading and unloading testing results were made. The overall stability, the integrity of rock mass, and the failure pattern transition under loading and unloading processes were systematically examined. In addition, for the two unloading cases with different vertical stresses imposed, the failure patterns were both identified as the collapse of the V − shaped extruded sidewall, due to the coupling of the shear failure and the vertical tensile failure in the sidewall wedge.

Xiwu Zhou, Wen Zhang, Xiangyu Wang et al.

In this study, the lateral impact tests of six RC piers which were protected by closed-cell aluminum foam (CCAF) were carried out by making use of an ultrahigh drop hammer horizontal impact test system. The protective effects of CCAF with different densities on the piers were then analyzed. The data regarding the piers’ impact force, displacement, reinforcement strain, and crack and damage development were mainly collected during the experimental testing processes. The results indicated that, when the impact energy was less than 7258 J and the density of the CCAF was 0.45 g/cm3, the cumulative impact force and displacements of the piers decreased by 67% and 35%, respectively. Therefore, it was considered that the CCAF with a density of 0.45 g/cm3 had displayed the best protective effects at that stage. It was also observed that when the impact energy was greater than 7258 J and the density of the CCAF was 0.55 g/cm3, the cumulative impact force and displacements of the piers decreased by 25% and 18%, respectively. Therefore, the CCAF with a density of 0.55 g/cm3 had displayed the best protective effects at that stage. Furthermore, under the conditions of constant accumulative impact energy, the protective effects of CCAF on the piers were observed to be weakened if it entered the densification stage too early and high-yield platforms were formed due to the density levels becoming too high. However, it was found that reasonable density and thickness increases could effectively delay the entry of CCAF into the densification stage, which effectively reduced the shearing effects which occurred when the impact speeds were too high, thereby preventing the shear failure of the piers.

Li Yazhou, Dong Li

In recent years, with the rapid development of social economy and highway transportation, the phenomenon of overweight transportation is increasingly serious, which is the main reason for the frequent occurrence of bridge collapse accidents in our country, causing heavy economic losses and casualties to the society.Due to the lack of unified bridge load limit management standards at the national level, it is difficult to fundamentally improve the adverse situation of bridge overload operation by relying on the existing overlimit management measures.Based on this background, we made the following work:(1) load carrying capacity check and calculation of prestressed hollow slab bridge: check whether the bridge used meets the requirements of the specification, so as to provide a reliable engineering basis for the analysis of load limit value in the following paper.According to the 04 specification, the load carrying capacity of the car is checked and calculated to verify whether the bridge meets the design requirements of the load carrying capacity.Then, the mid-span deflection of the bridge and the crack resistance of the main beam are checked to determine whether the bridge meets the design requirements in the normal limit state of use.(2) prestressed hollow slab bridge limit load values adaptability analysis first, calculates the design safety grade level on the limit load of prestressed cored slab jointless security levels of primary, secondary and tertiary limit load vehicle load effect, on this basis, from bearing capacity limit state and serviceability limit state analysis of the bridge limit load values of adaptation.

Rem W. Collier, S. Russell, David Lillis

Agent-Oriented Programming (AOP) researchers have successfully developed a range of agent programming languages that bridge the gap between theory and practice. Unfortunately, despite the in-community success of these languages, they have proven less compelling to the wider software engineering community. One of the main problems facing AOP language developers is the need to bridge the cognitive gap that exists between the concepts underpinning mainstream languages and those underpinning AOP. In this paper, we attempt to build such a bridge through a conceptual mapping that we subsequently use to drive the design of a new programming language entitled ASTRA, which has been evaluated by a group of experienced software engineers attending an Agent-Oriented Software Engineering Masters course.

Emilia Kuliczkowska

In this paper, road pavement collapses resulting from sewer leakage are divided into six categories: negligible, marginal, considerable, serious, very serious and catastrophic, with the categorization being based on two criteria, both related to traffic safety, i.e., the number of fatalities caused by sinkholes, and the extent of the road pavement damage. The causes of road pavement collapses are also discussed. The study involved analyzing the deterioration of sewer pipes with long service lives, focusing on the most common materials, i.e., concrete and vitrified clay. The results of the sewer inspections performed by the Kielce University of Technology suggest that the spot and linear defects detected in sewers of this type can be divided into three groups. The findings were used to formulate some recommendations on how to improve road traffic safety by preventing road pavement collapses.

Damian Beben, Adam Stryczek

The paper presents a numerical analysis of corrugated steel plate (CSP) bridge with reinforced concrete (RC) relieving slab under static loads. Calculations were made based on the finite element method using Abaqus software. Two computation models were used; in the first one, RC slab was used, and the other was without it. The effect of RC slab to deformations of CSP shell was determined. Comparing the computational results from two numerical models, it can be concluded that when the relieving slab is applied, substantial reductions in displacements, stresses, bending mo­ments and axial thrusts are achieved. Relative reductions of displacements were in the range of 53–66%, and stresses of 73–82%. Maximum displacements and bending moments were obtained at the shell crown, and maximum stresses and axial thrusts at the quarter points. The calculation results were also compared to the values from experimental tests. The course of computed displacements and stresses is similar to those obtained from experimental tests, although the absolute values were generally higher than the measured ones. Results of numerical analyses can be useful for bridge engineering, with particular regard to bridges and culverts made from corrugated steel plates for the range of necessity of using additional relieving elements. First published online: 15 Jan 2015

Mustafa Akgul, Murat Demir, Tolga Ozturk et al.

Forest road planning is a time-consuming and complicated process both because it requires environment-friendly road building, and due to the requirement to observe economic costs. This costs will be increase depending on maneuverability requirements of vehicle dimension. The main aim of this study is to analyze maneuverability of recreational vehicles on forest roads that primarily serve utilization of vehicles intended for production as well as geometrical characteristics of roads on computer environment. Both dynamic horizontal driving analysis and dynamic vertical driving analysis can be made with Autopath driving analysis module of Plateia 2013 software. Computer-aided horizontal driving analysis, which is used in examination of opportunities for utilization of available roads by different vehicle types, appears as an effective method for the decision maker in consideration of geometrical standards of vehicles during decision-making process. Graphical report is another output of driving analysis which visually presents vehicle maneuverability. In this context, Maneuverability of automobile, midibus and bus were analyzed on forest road with 4 m platform width. As a results of this study, it was concluded that computer-aided driving analysis is a beneficial tool in decision making process for re-planning of forest roads. As a consequence, it is considered that driver safety, as well as project costs, would increase by utilization of driving analysis during forest road planning and design.

L. Haefner