Bridge Project Research Articles

Data-driven corrosion failure probabilistic assessment model for reinforced concrete structures

The corrosion-induced failure of marine reinforced concrete structures, stemming from prolonged exposure to environments with elevated chloride content, poses a significant threat to structural integrity and serviceability. Traditional models predominantly depend on prior information to estimate the spatial stochastic degradation of aging structures, leading to a lack of comprehensiveness and accuracy in evaluation results. To address these limitations, a data-driven probabilistic assessment model for corrosion failure is proposed. This model incorporates a pre-training phase that integrates electrochemical simulations with long-term exposure data to establish the spatiotemporal distribution of corrosion failures, thereby facilitating a thorough assessment of overall damage by quantifying the corrosion failure proportion while propagating epistemic uncertainty. Subsequently, a multivariate function is derived using the non-dominated sorting genetic algorithm to elucidate the relationship between input and output variables. The efficacy of the data-driven model is evaluated through experimental observations and model predictions. The Hangzhou Bay Bridge project serves as a case study, wherein this model is demonstrated using actual data obtained from exposure experiments and field detection. Furthermore, the proposed model enables a rapid prejudgment of corrosion failure proportion, significantly reducing diagnostic time compared to conventional procedures.

The BRIDGE project: a feasibility randomised controlled trial of brief, intensive assessment and integrated formulation for young people (age 14-24) with features of borderline personality disorder (Protocol).

Borderline personality disorder (BPD) is a severe mental disorder that is characterised by a pervasive pattern of instability of interpersonal relationships, self-image, and mood as well as marked impulsivity. BPD has its peak incidence and prevalence from puberty through to emerging adulthood. BPD is a controversial diagnosis in young people. Commonly, young people with BPD are under-diagnosed, untreated, are not in employment or training and are estranged from their families. Yet, they have complex needs and are at high suicide risk. To assess the feasibility of conducting a randomised controlled trial (f-RCT) of a BRIDGE, a brief intervention programme for young people (age 14-24) with BPD symptoms (sub-threshold or threshold) in a community sample from Scotland, UK. Forty young people (age 14-24) meeting criteria for BPD symptoms, will be randomised in a 1:1 ratio to receive either a) the BRIDGE intervention plus service-as-usual or b) service-as-usual alone. Follow up will be 12 weeks and 24 weeks post-intervention. The study is carried out between 2021 to 2024. The two primary outcomes of the MQ funded, BRIDGE project (f-RCT) are i. recruitment rates and ii. retention rates. The study will present the acceptability and appropriateness of our putative outcome measures for a future definitive randomised controlled trial (d-RCT). Young people with BPD benefit from good clinical care and targeted intervention, however are regularly missed or mislabelled. The community based feasibility trial would provide initial evidence of variable needs of young people with complex needs, who maybe missed or excluded from services as they don't "fit" a model/diagnosis. Workable multi-agency service model proposed in the trial would be a major advance in understanding care pathways regardless of trial outcome. ClinicalTrial.gov, identifier NCT05023447.

Propagation Effect Analysis of Existing Cracks in Box Girder Bridges Based on the Criterion of Compound Crack Propagation

Cracking in concrete box girder bridges will have a significant impact on the safety and durability of the structure, and many box girder bridges which are in service have undergone varying degrees of cracking. Currently, the safety design of actual bridge projects place an emphasis on the stress or the load value of a cross section at the limit value specified in the code for safety control. This design method assumes that the member itself is of uniform and continuous material and is internally undamaged. However, the bridge structure is more or less cracked to varying degrees during the period from casting to construction to operation of the concrete members. In this paper, a finite element computational model of a three-span prestressed concrete box girder bridge with existing cracks is established based on the fracture mechanics theory, and the critical parameters of crack extension are introduced to evaluate the extension state of cracks. At the same time, the extended stability of the existing cracks of the box girder bridge is analyzed by considering the temperature effect, vehicle loading, and prestressing loss, and the sensitivity of crack extension under each working condition is investigated. The results show that, with the increase in crack length and depth, the crack expansion is promoted, but the effect is relatively small, and the maximum stress intensity factor is only 6.48 MPa mm1/2. Under the multi-factor coupling effect, the cracks show a composite crack expansion dominated by type I cracks, the longitudinal cracks of the existing base plate are in a stable state, the maximum value of the crack expansion critical parameter of the vertical cracks of the webs reaches 1.087, and there is a tendency to expand locally. The maximum value of the critical parameter for crack extension of the vertical crack in the web plate reaches 1.087, and there is a tendency towards local expansion. The crack extension evaluation criteria proposed in this paper have a certain reference value for crack extension research on similar concrete box girder bridges and provide a scientific basis for the optimized design of similar bridges.

Study on Fracture Delay of High-Strength Bolts in Road Bridge Maintenance

In the maintenance work of highway and bridge engineering structures, the fracture delay of high-strength bolts is a content that needs to be focused on and researched. Based on this, the paper analyzes the fracture delay of high-strength bolts in highway bridge maintenance, including an overview of the fundamental research on fracture delay and related specific studies. It is hoped that this study can provide scientific reference for the reasonable maintenance of high-strength bolts, so as to ensure the overall maintenance effect of highway bridge projects.

Tuned mass dampers ‐ evaluation of the effect on two real footbridges

AbstractPedestrian comfort, subtle design, minimizing the number of fixed supports of the footbridge or material saving. These are the key arguments for integrating tuned mass dampers into the bridge project. The goal is to protect people and structure from vibrations and damage. The following paper presents findings from the design, production and tuning of mass dampers, their optimization possibilities and benefits for bridge engineering. The validity of damper design was verified on two footbridges in the Czech Republic and Slovakia. It concerns the footbridge over the Svitava River in Bílovice nad Svitavou and the footbridge over the high‐speed road in Banská Bystrica. Dynamic tests including measurement were carried out on both bridges before and after the installation of the dampers. The dynamic monitoring of the compliance of modal parameters was conducted using operational modal analysis (OMA). The evaluation of the dynamic tests also includes the response to pedestrian effects (comfort criteria) and the determination of the logarithmic decrement of the damping.

Steel solutions for a sustainable bridge infrastructure of today and tomorrow

AbstractResponsible for 70% of the global CO2 emissions, infrastructure has a significant impact on our climate and the related consequences. Bridges are a major keystone of the infrastructure and take a leading position in its decarbonization. In this framework, low‐carbon emission steels play an important role. Low‐carbon emission steels, like ArcelorMittal's XCarb® recycled and renewably produced steels, are already available on the market. Combining scrap and renewable electricity, it offers very low levels of CO2 emissions per ton of finished steel. The present paper describes how different steel solutions can be combined to lower the material input, to simplify the construction process and to reduce the maintenance efforts in bridge construction. The impact of efficient design has been assessed by a Life‐Cycle Assessment (LCA) for bridge solutions with small and medium spans of up to 40 m. The paper concludes with a summary of recently realized bridge projects in Poland.

Cost-benefit Analysis of PPP Construction Projects

This paper discusses the cost and benefit of the cross-river Bridge PPP construction project in Y City, and analyzes the application of PPP model in China and its economic benefits. Research shows that PPP model not only effectively alleviates traffic pressure and promotes regional economic development, but also significantly reduces project construction and transportation costs and improves the quality of public services through social capital investment and operation. As a typical case, the cross-River Bridge project accounts for 95% of social capital, and its successful implementation validates the significant advantages of the PPP model in improving economic and social benefits. In the national economic evaluation, the project made fine adjustments to the investment cost, including the application of shadow price and the adjustment of the conversion factor of labor wages, to ensure the accuracy of the evaluation results. In addition, the technical and economic data of various types of motor vehicles are listed in detail, especially the adjustment of the cost of motor transportation related to time, which provides an important cost reference for the transportation industry. Through the comprehensive analysis of the theoretical basis, practical application and economic cost and benefit of PPP model, this paper not only enriches the cost and benefit analysis theory of PPP projects, but also provides valuable practical experience and theoretical support for similar projects. Looking ahead, suggestions such as improving the governance system and strengthening risk management and control will promote the widespread application of the PPP model in China and inject new vitality into economic and social development.

Evolution of microstructure and mechanical properties along the thickness direction of 500 MPa HSLA steel heavy plates

High strength heavy plates with large thickness are demanded for the construction of large-span bridge projects. However, there is a lack of understanding on the microstructure evolution and mechanical properties through the entire thickness of heavy plates with yield strength over 500 MPa, especially manufactured by the thermo-mechanical control processing (TMCP) and tempering (T) process. In this research, the microstructure and mechanical property evolution through the thickness was investigated for the 85 mm thick, 500 MPa grade heavy steel plate manufactured by TMCP + T. The results show that the microstructure throughout the thickness predominantly consists of granular bainite (GB) and polygonal ferrite (PF). The yield strength and tensile strength at 1/8t, 1/4t, 3/8t and 1/2t (t, the thickness) are 659.4 MPa, 520.6 MPa, 500.3 MPa and 494.0Mpa, and 739.2 MPa, 642.9 MPa, 627.8 MPa and 625.2 MPa, respectively. Yield and tensile strength both significantly decline from 1/8t to 1/2t. The strengthening mechanisms at different thickness were analyzed, and grain refinement has the most significant contribution. In addition, the mechanical properties of ferrite/bainite heterostructure were analyzed by Cyclic load-unload-reload (LUR) tests. The hetero-deformation induced (HDI) stress increases from 1/8t to 1/2t. At 1/8t, HDI hardening is higher but occurs over a narrower strain range compared to that at 1/2t. The impact energy at −40 °C for 1/8t, 1/4t, 3/8t and 1/2t are 182.7 J, 213.0 J, 242.2 J and 253.7 J, respectively. It was discerned that PF undergoes plastic deformation and absorbs a large amount of energy, constituting the primary rationale for the enhanced impact toughness at 1/2t compared to 1/8t. Through this research, not only the microstructure and mechanical property evolution through the thickness was revealed, but also the ferrite/bainite microstructure was found a promising heterostructure to obtain high strength, high toughness and low yield ratio for heavy plates.

Major Bridges of Bangladesh: Engineering Marvels and Infrastructural Icons

Bangladesh is a riverine nation in South Asia with a 580 km coastline on the northern littoral of the Bay of Bengal. Our country has 213 rivers, and 20 significant bridges have been built. As populations grow and urban and rural landscapes evolve, the demand for innovative and efficient bridge structures becomes increasingly apparent. With its numerous rivers and water bodies, Bangladesh has faced the challenge of providing efficient and safe transportation infrastructure. Over the years, the construction of significant bridges has become crucial for connecting regions, promoting economic growth, and enhancing accessibility. This paper explores the historical background, geographical challenges, and economic significance of major bridge projects in Bangladesh. This paper looks at how bridges in Bangladesh have changed over time, focusing on essential projects that helped shape the country's infrastructure. The paper studies explicitly main bridges like Padma Bridge, Jamuna Bridge, and Shah Amanat, Lalon Shah, and others in Bangladesh. It looks at their designs, how they were built, and how they contribute to the country's development. Factors including the span length, site conditions, aesthetics, and engineering considerations influence the choice of bridge type.

Application of digital transformation in real-time bridge monitoring systems: a case study with GNSS, accelerometer and IoT solution

Abstract Digital transformation is a term that has recently become more popular in all industries such as economics, financial fields, and engineering. The development of the Internet of Things, smart sensor systems, and cloud computing is the basis for forming effective solutions in construction monitoring from cyclic monitoring and post-processing to real-time monitoring and processing; from physical storage systems to virtual systems, and connecting every component in the project. This article presents a study and application of advanced devices including GNSS, acceleration sensors and IoT solutions in bridge construction monitoring. The research aims to apply smart devices and IoT to build real-time monitoring modules for bridge projects following the digital transformation trend. The study uses a GNSS N3 Comnav receiver with a sampling interval of 1Hz, an MPU 6050 acceleration sensor with a sampling frequency of 250 Hz, and an ESP Wi-Fi module. The result of the research is a real-time wireless monitoring system that operates effectively and economically and initially processes data with GNSS and high-frequency acceleration sensors.

Optimisation of Bridge Pier Winding Flow Numerical Simulation Scheme Based on Delft3D

The majority of existing numerical simulations of the effect of bridge piers on water’s movement are based on a limited number of bridge piers at a laboratory scale. Furthermore, some 2D numerical simulations for actual bridge projects have deficiencies, including the use of overly large meshes and an inadequate treatment of bridge piers. In this study, we compare three methods (structural mesh encryption, suspension mesh, and non-structural mesh) based on Delft3D, and we apply the optimisation scheme to a real bridge project. It is demonstrated that optimal results can be achieved by utilising a grid size comparable to the pier diameter (Dp) in the region away from the pier. In the vicinity of the pier, the grid cell size should be no larger than 1/9 Dp. The suspended grid technique (DD Boundary) can yield results consistent with those obtained using a full-area high-resolution grid, provided that the total grid number can be reduced and the computational time is considerably reduced. In this study, the unstructured mesh (Delft3D Flexible Mesh) scheme was unable to capture the oscillations in the wake flow behind the bridge piers. However, the application of the optimised scheme in bridge engineering demonstrated its practical value. The findings of this study on mesh resolution and suspension mesh schemes can be applied to the Delft3D software and are also useful for other numerical simulation work.

Safety Evaluation for Fabricated Small Box Girder Bridges Based on Fuzzy Analytic Hierarchy Process and Monitoring Data.

During the operation of fabricated small box girder bridges, which face safety issues such as structural degradation and failure, there is an urgent need to propose a safety evaluation method to cope with the possible risks. This article quantitatively evaluates the safety state of a fabricated small box girder bridge in Wuhan City based on Fuzzy Analytic Hierarchy Process (FAHP) and structural health monitoring (SHM) data. Firstly, the FAHP model is established, and stress, deformation, and temperature are selected as evaluation factors. The safety thresholds of stress and deformation are determined by combining the industry specifications and the historical statistical patterns of the massive SHM data. The temperature field of the bridge is simulated and analyzed by combining ANSYS, HYPERMESH, and TAITHREM, and the most unfavorable temperature gradient is determined as a threshold for the safety evaluation. Finally, the scores of indexes of the bridge are determined based on the measured SHM data, which in turn provides a quantitative description of the safety state. The results show that the thresholds determined by the joint industry specifications and the massive SHM data are reasonable; the temperature field simulation model established in this article is consistent with the measured results, and can accurately determine the temperature gradient of the bridge. The safety evaluation result from the FAHP model is the same as the field test results, which verifies the effectiveness and applicability of the proposed method to actual bridge projects.

Prioritizing Trail Bridge Construction Projects in Nepal Using Linear Discriminant Analysis

The country of Nepal desperately requires trail bridges to foster rural connectivity and socio-economic progress especially in the remote areas. However, despite their significance, political meddling among other socio-economic factors has continuously influenced bridge construction priorities resulting in a non-uniform distribution that does not always match key indicators like population density, disadvantaged population or number fatalities due to river crossing. This report identifies Linear Discriminant Analysis (LDA) as an objective and fair approach for prioritizing bridge projects. This research will provide a structured way of ranking these bridges with reduced political influence and consequently decreasing social disparities through focusing on such criteria as benefiting homes, total population, disadvantaged population, time saved, type of rivers and risk factor. Trail bridges were in history demanded by Nepal since 1950s in a bid to receive international aid and community-based construction. The participation of the communities in the planning, designing and maintenance of these bridges has increased over time thus promoting sustainability and ownership. However, there are still challenges that remain to ensure equitable distribution of bridge projects that adequately address the needs of the most marginalized groups. Through LDA application, this research demonstrates how priority classes can be effectively separated to objectively determine areas with urgent need for bridge constructions by decision makers. From the analysis it is clear that bridges can be ranked by using socio-economic or geographical data that is quantifiable in order to promote fair infrastructure development. The nexus between traditional knowledge and modern analysis techniques toward sustainable equitable infrastructural development in Nepal cannot be overemphasized by the findings from this study. This. therefore, strengthens rural community resilience while also ensuring resources are distributed based on objective requirements but not political or socio-economic influences.

Supervised learning to covering cost risk through post-construction evaluation of transportation projects by project delivery methods

PurposeThe main objectives of this study are to (1) develop and test a cost contingency learning model that can generalize initially estimated contingency amounts by analyzing back the multiple project changes experienced and (2) uncover the hidden link of the learning networks using a curve-fitting technique for the post-construction evaluation of cost contingency amounts to cover cost risk for future projects.Design/methodology/approachBased on a total of 1,434 datapoints collected from DBB and DB transportation projects, a post-construction cost contingency learning model was developed using feedforward neural networks (FNNs). The developed model generalizes cost contingencies under two different project delivery methods (i.e. DBB and DB). The learning outputs of generalized contingency amounts were curve-fitted with the post-construction schedule and cost information, specifically aiming at uncovering the hidden link of the FNNs. Two different bridge projects completed under DBB and DB were employed as illustrative examples to demonstrate how the proposed modeling framework could be implemented.FindingsWith zero or negative values of change growth experienced, it was concluded that cost contingencies were overallocated at the contract stage. On the other hand, with positive values of change growth experienced, it was evaluated that set cost contingencies were insufficient from the post-construction standpoint. Taken together, this study proposed a tangible post-construction evaluation technique that can produce not only the plausible ranges of cost contingencies but also the exact amounts of contingency under DBB and DB contracts.Originality/valueAs the first of its kind, the proposed modeling framework provides agency engineers and decision-makers with tangible assessments of cost contingency coupled with experienced risks at the post-construction stage. Use of the proposed model will help them evaluate the allocation of appropriate contingency amounts. If an agency allocates a cost contingency benchmarked from similar projects on aspects of the base estimate and experienced risks, a set contingency can be defended more reliably. The main findings of this study contribute to post-construction cost contingency verification, enabling agency engineers and decision-makers to systematically evaluate set cost contingencies during the post-construction assessment stage and achieving further any enhanced level of confidence for future cost contingency plans.

Characteristics Comparison and Case Study of Traditional Anti-Slip Saddles and Innovative Rolling Saddles in Highway Long-Span Bridges

The cable saddle structure is the main support component for long-span bridges to transmit cable force, which is of great significance for the structural force system. Nowadays, the main cable saddle structures used in long-span bridges are mainly traditional anti-slip saddles and innovative rolling saddles. To clarify the characteristics of the saddles in long-span bridges, the design principles, mechanical properties, and casting process of these two types of saddle structures were researched. A rolling saddle in a bridge project was taken as an example and its mechanical situation in the roller area was investigated. The results showed that the stress concentration phenomenon is prone to occurring in the rolling saddle because of the line contact in the contact area and the rolling saddle is mainly subjected to vertical force. Thus, attention should be paid to the von Mises stress in the contact area between the saddle base and the roller shaft, the lower surfaces of both ends of the roller shaft, and the top surface of the tower, to avoid material damage. Furthermore, the casting process of the anti-slip saddle structure is mature, but also faced with problems due to the welding of thick plates, and urgently needs to be improved and upgraded. The rolling saddle is used with the all-welded casting process, but its technology is relatively immature and the requirements for the roller shaft material performance are strict. The research results can provide a reference for the selection and design of the saddle structure in long-span bridges.

Analysis of Road Bridge Repair and Strengthening Construction Technology

Highway infrastructure plays a crucial role in the healthy development of the social economy. Therefore, China has invested a lot of financial resources in the construction of road and bridge projects in recent years, resulting in the rise in scale and number of road and bridge projects. Simultaneously, the quality of road bridges has garnered widespread attention, necessitating an exploration of common hazards associated with road bridges and the significance of their reinforcement. It is essential to delve into specific technical methods to enhance the quality and service life of road bridges. This paper elaborates on the common hazards faced by road bridges and proposes maintenance and reinforcement strategies to promote the healthy development of road bridge engineering.

Service Life Design of Reinforced Concrete Maritime Infrastructure: Holistic Approach with Experiences from Chilean Cases

The consideration of the useful life of reinforced concrete in the different stages of a structure's life cycle, as a distinguishing factor in the design process for performance under aggressive environmental conditions, has presented new challenges in construction. This includes the development of new regulations incorporating innovative engineering materials, performance tests and modeling processes to estimate concrete deterioration over time, and construction processes ensuring adequate Quality Control and Quality Assurance (QAQC). As a result, infrastructure projects have been able to exceed their intended lifespan, maintaining serviceability levels for more than 100 years. One such example is the Chacao Bridge project currently under construction in southern Chile. This paper provides an overview of project stages from a holistic approach, focusing on aspects inherent to planning including design and construction processes, control stages for monitoring deterioration levels through regular diagnostics and appropriate monitoring to support ongoing structural health management. Additionally, it presents real case design examples carried out with specific models created for each case.

How a project design becomes a macro-actor: laboratory simulations in trials of strength between competing bridge designs, project budgets and sustainability

PurposeThis paper shows how Bruno Latour’s novel work and methodological approach can enrich management and organization studies, accounting and science and technology studies on what it takes to redesign sustainable societal infrastructures. Latour’s notions of trials of strength, macro-actor and design as redesign are used in a case study to describe and analyse how the laboratory becomes decisive in negotiating the bridge design and project budget to the benefit of a more sustainable transport infrastructure.Design/methodology/approachLatour’s notion of the detective-author is used to research and write a longitudinal qualitative case study that reconstructs the project processes and chain of related events by following the actors/actants.FindingsThe case analysis shows how a project design becomes an emerging powerful macro-actor through the mobilization of laboratory simulations and calculations. The role of the project budget changes; from a strong supporting role as input to a decision option in favour of a cheaper stayed bridge to a weak role as an output from a process of redesign supporting a much larger, costlier and more sustainable suspension bridge.Originality/valueWe use Latour’s methodological approach to engage primarily in detailed process descriptions to go beyond the often-pointless call for further theory development and to rather account for what is at work in specific situations. Latour’s notions of redesign as an outcome from trials of strength, we consider a useful approach to further our understanding since it also takes account of the distributed knowledge production that is integral to the actors’ cognitions and recognitions. Relatedly, the specific Latourian notion of redesign opens up new avenues for researching the more or less powerful role accounting devices such as a project budget can play in valuing, supporting and/or undermining the design of sustainable societal infrastructures.

Analysis of the Impact of the Former Abandoned Dregs of Mountain Highways on the Construction and Safety of New Bridge Pile Foundations

In highway reconstruction and expansion projects, the impact of the abandoned dreg body produced by the original highway on the new bridge project cannot be ignored. If the abandoned dregs are not handled properly, they will cause great threat to the operation of the new highway as well as to the safety of the surrounding environment and personnel. In this paper, based on a South China highway reconstruction and expansion project, a model of the abandoned dreg body, bridge pile and anti-slide pile is established with the help of finite difference software FLAC3D 5.0. The calculation results show that compared with burying the anti-slide pile, slope cutting is more effective for improving the stability of the abandoned dreg body. Under the action of vertical force intensity, the displacement of the top of the pile increases continuously, and the maximum bending moment of the pile body increases firstly and then decreases. The pile displacement and bending moment of the bridge pile increase significantly in the storm condition compared with the normal condition. In addition, the abandoned dreg body hazard prevention and control technical measures are studied. The impacts of different locations of anti-slide pile burial on bridge piles are analyzed and compared, and it is determined that the optimal location of anti-slide pile burial is the middle of the secondary slope.

EXPLORING THE SUSTAINABILITY OF CONCRETE BRIDGES

After the construction boom of the past 30-40 years, United Arab Emirates has been left with many costly structures that may or may not fulfill modern sustainability requirements. With the on-going economic recession seen by most of the world and a higher awareness among the population regarding the environmental and societal impact of construction, engineers and designers are carrying out sustainability studies for all kinds of infrastructure. Although most of past research has focused on sustainability rating of buildings, recent advances in this area shows a heightened interest in sustainability assessment of bridges as well. Several of the key sustainability indicators for buildings are also applicable for bridge; quantitative (construction cost and assembly, transportation of materials, service life, environmental impact, etc.) and qualitative (aesthetics, safety features, etc.). This paper contributes to an ongoing research project aimed at developing a sustainability rating system for bridges in the UAE. It includes a comprehensive survey designed to evaluate the relevance of current sustainability indicators for bridge projects within the region. The findings and analysis of this survey are discussed, providing insights into the adaptation of these sustainability metrics for UAE bridges.