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This paper focuses on the design as well as on the experimental and numerical validations of the mechanical behavior of a precast ultra-high performance fibre reinforced concrete (UHPFRC) retaining walls. The design, made in accordance with the Canadian Highway Bridge Design Code (CSA S6, 2019), led to the fabrication of a full-scale UHPFRC retaining wall with 3% fibre content which had dimensions of 3 m in height, 2 m in length, 2 m in width, with two vertical and horizontal stiffeners, and very thin vertical and horizontal panels of 40 and 65 mm, respectively. The experimental tests showed that the UHPFRC retaining wall exceeded by 42% the ultimate limit state (ULS) design factored bending moment and showed a very ductile behavior under flexural loading. At service limit state (SLS), the retaining wall had maximum crack opening between 0.15 and 0.28 mm, and a maximum lateral displacement of 4 mm. The finite-element model developed for the application captured accurately the flexural behavior of the UHPFRC retaining wall and was used later in parametric studies to optimize the design. The retaining wall optimal design includes UHPFRC with 3% fibre content and stiffeners with variable cross-section which allows volume reductions of 73% for concrete and 86% for rebars in comparison to the conventional reinforced concrete design. [ABSTRACT FROM AUTHOR]

The Canadian Highway Bridge Design Code (CHBDC) uses the concept of a target reliability index for evaluating the load carrying capacity of existing bridges. This index, which is based on risk to human life, relates to three aspects of uncertainties inherent in a bridge: (a) element behaviour, (b) system behavior, and (c) inspection level, where the inspection level currently refers to only manual inspections. Citing examples of tests on many instrumented bridges, the paper proposes an additional inspection level for inspections done with the help of electronic instruments and tests under controlled vehicle loads. The paper proposes simple additions to clauses of the CHBDC, for use when determining the optimum load carrying capacities of existing bridges where structural health monitoring information is available. [ABSTRACT FROM AUTHOR]

In the context of the construction of road infrastructure facilities, there is no doubt that the construction of new roads leads to an increase in the quality of transport services. A new road fosters the development of settlements through which it passes, and indirect benefits are achieved through new investments. Cost-benefit analysis (CBA) as a method involves consideration of a project's financial returns, and most data on project costs and benefits are obtained through a relatively detailed financial analysis. Any independent variable reflected in the change results in a set share in project analysis; it is a critical variable and must be evaluated as reliably as possible. The implementation of a historical capital project in the Republic of Croatia has been highlighted in this paper - the construction of the Pelješac Bridge. Based on the transport criterion, the research has shown significant advantages achieved by bridge construction in the surrounding and wider area. The positive effects of demographic, economic, and social parameters are multiplying. The economic effects of bridge construction are highly favourable since, on the one hand, they are expressed as benefits in terms of savings on the costs of all activities from primary to quintary. On the other hand, they represent multiplications regarding the use and revitalisation of employment and natural resources. In accordance with the expected faster economic growth, the offer structure will cause a change in the relations within service activities in the direction of strengthening investments, intellectual services, tourism with all of its accompanying activities, etc. In the case considered, nonmeasurable benefits have not been quantified, although, independently from the CBA, their feasibility is fundamental. Nota bene, this primarily refers to the political component in strategic decisionmaking, such as the integration of regions, i.e., the achievement of the state territory integrity. [ABSTRACT FROM AUTHOR]

Military vehicles are sometimes required to transit bridges owned and operated by civilian bridge authorities. Using available data regarding the gross vehicle weight and associated axle loads of military traffic, live load factors, calibrated to the Canadian Highway Bridge Design Code, are proposed for bridge design and evaluation. This paper recommends live load factors for three categories of military vehicles: (i) wheeled-transport vehicles; (ii) wheeled-fighting vehicles; and (iii) tracked-fighting vehicles. The values are derived for interior girders of simply supported slab-on-girder bridges subjected to a single lane of traffic loading and are believed to be generally applicable for other structural elements and bridge types. Inherent differences between fighting vehicles, which are heavily armoured, and transport vehicles, which although armoured have high payloads, suggest that highway bridges should be evaluated separately for military fighting vehicles and military transport vehicles using distinct live load factors. [ABSTRACT FROM AUTHOR]

The paper takes a Yangtze River bridge as the object, establishes a finite element model of the highway orthotropic steel deck structure, calculates and analyzes the fatigue stress of specific structural details based on the hot spot stress method, and obtains the fatigue vulnerable area of this type of bridge deck structure. Based on the bridge’s actual use, the thesis calculates and evaluates the fatigue life of the typical welding details of the bridge deck based on the American Highway Bridge Design Code. The results show that the fatigue stress amplitude calculation of the five types of fatigue vulnerable structure details under the Fatigue Ⅰ and Fatigue Ⅱ limit states. The values are all less than the allowable value, and the fatigue life meets the design requirements. [ABSTRACT FROM AUTHOR]

Approximately a quarter of the bridges in the United States are classified as either functionally obsolete or structurally deficient by the United States Department of Transportation (USDOT). As such, transportation agencies are challenged to handle the increasing need of upgrades with limited resources. Accelerated Bridge Construction (ABC) can reduce the construction duration and can decrease the environmental and socio-economic impacts of repair and upgrade activities by minimizing traffic disruptions. As several states are using accelerated construction techniques, a standard guideline would be highly beneficial for these agencies in developing or improving the ABC decision-making process. As problems are often project specific, a decision tool can assist in determining the viability of ABC over traditional construction methods and in selecting appropriate construction and contracting strategies on a case-by-case basis. This paper presents findings of a recent survey with regards to utilization of ABC strategies by state Departments of Transportation (DOTs), and a decision support framework which consists of three models: (1) Analytical Hierarchy Process (AHP) based ABC vs. traditional construction decision-making model; (2) ABC alternatives selection model; and (3) procurement method and contract selection model. The paper also discusses the use of ABC in New York State and describes a New York State bridge project to validate the AHP model. [ABSTRACT FROM AUTHOR]

This paper describes the development of a unique rolling load simulator (ROLLS) for testing bridge superstructure with a footprint up to 4 m ×17 m, and its first application to test a full-scale 1220 mm ×900 mm ×16000 mm B900 prestressed concrete box girder. This facility at Queen's University in Kingston, Ontario, is the first of its kind in Canada. ROLLS can apply cyclic loading in a controlled laboratory environment, under realistic highway scale 'rolling wheel loads', in lieu of the conventional 'pulsating stationary loads'. It has two half-axles of a large tandem, each comprising a dual 1140 mm diameter air-inflated tires spaced at either 1.2 or 2.4 m. Each half-axle can apply up to 125 kN, representing the heaviest half-axle load of the CL-625 design truck of the Canadian Highway Bridge Design Code (CHBDC). The maximum travel range and speed are 14.9 m and 6 m/s, respectively. A case study involving analysis of a bridge with eight adjacent B900 box girders of 27.6 m span was carried out prior to experimentally testing one of the girders using ROLLS. Load distribution analyses were conducted using both (i) a finite element model of the full bridge under various CL-625 truck loading configurations and (ii) the CHBDC load distribution method, and both agreed well. Scaling analysis of the girder load share was then conducted to account for shortening it to 16 m to fit in the laboratory, resulting in two-115 kN ROLLS design loads, 1.2 m apart. Multiple passes were conducted at various loads of 40%–100% of the design load, at speeds of 1–5 m/s to examine the machine and girder behaviours. It was found that the applied load fluctuates by less than 10% of full capacity and a 0.13 s/cycle time lag occurs. The measured girder deflection and elastic strains were 11%–20% lower than predicted theoretically. With the two half-axles assembly spaced at 1.2 m, the apparatus has the ability to complete three million cycles in approximately 4.5 months if ran continuously at 5 m/s. [ABSTRACT FROM AUTHOR]

Building information modeling (BIM) has been widely adopted in the building industry. However, the use of BIM in civil infrastructure facilities, sometimes referred to as civil information modeling (CIM) has been slow in its application. Industry and academia are increasingly putting effort into CIM study and implementation, but so far there has been no comprehensive review of their effort in this regard. This paper presents a framework to evaluate the current practices of CIM adoption for various civil infrastructure facilities. In this study, civil infrastructure facilities were divided into nine categories for evaluation and the effort with regard to CIM adoption for each civil infrastructure category was evaluated in six aspects. Based on the evaluation and comparison results of 171 case studies and 62 academic papers on CIM, research gaps were identified and recommendations were made. For example, the findings show that data schema development for civil infrastructure facilities other than bridges, roads, and tunnels are lacking. The results and research gaps revealed by this study are useful for both researchers and practitioners. [ABSTRACT FROM AUTHOR]

The A82 is a primary route in Scotland that follows the shoreline of Loch Lomond. Following a landslide in the late 1970s, traffic lights were implemented, limiting vehicles to one-way traffic. A widening scheme was required to restore the two-way carriageway over a 400 m length. This scheme included a six-span 168 m viaduct curved in plan to follow the existing road alignment. The form of the structure was highly influenced by the site topography, the adjacent soil/rock slope profile and the loch shoreline. It aimed to provide an economical, buildable solution while minimising intrusion into the sensitive environment and minimising traffic disruption during construction. To meet these criteria, the design was developed to suit a phased construction. A full-length contiguous piled retaining wall supported the existing carriageway and facilitated installation of a trapezoidal steel-concrete composite box-girder viaduct. Partial construction of the deck slab allowed a temporary switch of traffic, enabling the remainder of the bridge works to be completed on the original road alignment. Once constructed, the 3000 t deck was jacked-up to its permanent position using 82 synchronised hydraulic cylinders. This paper summarises how design and construction of the viaduct was achieved in its challenging environment. [ABSTRACT FROM AUTHOR]

This paper deals with the cost optimization of road bridges consisting of concrete slabs prepared in situ and two precast-prestressed U-shaped beams of self-compacting concrete. It shows the efficiency of four heuristic algorithms applied to a problem of 59 discrete variables. The four algorithms are the Descent Local Search (DLS), a threshold accepting algorithm with mutation operation (TAMO), the Genetic Algorithm (GA), and the Memetic Algorithm (MA). The heuristic optimization algorithms are applied to a bridge with a span length of 35 m and a width of 12 m. A performance analysis is run for the different heuristics, based on a study of Pareto optimal solutions between execution time and efficiency. The best results were obtained with TAMO for a minimum cost of 104 184€. Among the key findings of the study, the practical use of these heuristics in real cases stands out. Furthermore, the knowledge gained from the investigation of the algorithms allows a range of values for the design optimization of such structures and pre-dimensioning of the variables to be recommended. [ABSTRACT FROM AUTHOR]

Highway construction efficiency is critical to highway users such as the trucking industry given today's era of shortages in funding, and given the need for major re-investments in the highway system. One topic that can add to project costs relates to delays and how contractors are reimbursed for such delays. Delays are common in construction, especially in complex heavy highway and other infrastructure projects, and the claims they generate have negative effects on project schedules and costs. In spite of this, the analysis of claims is hindered due to the variety of methods and analysis techniques in use and lack of standardization in the incorporation of delay claim analysis methods in construction contracts. This paper reviews different methods for delay claim analysis and outlines their advantages and disadvantages. A case study of a bridge project is used to demonstrate the potential for manipulation by using different methods for the same delay case. The analysis shows clearly that a standardized process for delay claim analysis would improve highway construction contracting. Research needs to create a standardized process are outlined. [ABSTRACT FROM AUTHOR]

• The longitudinal stiffening of RC beams significantly affected CSP tunnel response; • Modelling the CSP tunnel shell with orthotropic characteristics leads to underestimating tunnel response compared to corrugated shell; • The method of modelling a steel shell affects the time of the appearance of maximum displacements, velocities and accelerations; • The duration of the seismic excitation affects the response of the soil-steel tunnel; • The results from Canadian Highway Bridge Design Code obtained are quite far from those obtained from FEM; Transport infrastructure, such as tunnels and underground structures, are usually built using reinforced concrete solutions. Since the 1970s, many transport structures (culverts, bridges, tunnels and animal crossings) have been made from corrugated steel plates and surrounding backfill (also known as soil-steel structures). These structures are a good alternative to reinforced concrete solutions because they can be built rapidly with substantial 40–50% cost savings. The behaviour of soil-steel structures under typical static and dynamic loads is reasonably well recognised. However, the seismic analysis of these structures is usually conducted in a limited range, mainly for small culverts. Therefore, it is important to know how soil-steel composite tunnels behave under seismic excitations. The analysis in this work was made for the Tolpinrud railway tunnel in Norway. The paper presents the numerical analysis under seismic excitations using the DIANA FEA program based on the finite element method. Non-linear models with the El Centro and Ancona records were used to analyse the problem. Four different numerical models of the tunnel were considered. The paper analyses two methods of modelling the steel shell of the tunnel and the impact of using reinforced concrete (RC) beams to strengthen the shell. In models I and II, the shell was modelled as corrugated, and in models III and IV as flat. Additionally, it was found that the influence of additional RC beams (models II and IV) is negligible. Moreover, significant frequencies caused by given seismic excitations were determined. It was also found that the use of destructive earthquakes of similar intensity and different duration caused a low level of stresses in the soil-steel tunnel models. As a result of the conducted research, it was recommended that model I is the most suitable for this type of analysis. The obtained results can help recognise the behaviour of such tunnels located in seismic areas. [ABSTRACT FROM AUTHOR]

• Soil-structure interaction of flexible corrugated metal pipes. • Design codes typically estimate conservative values for the internal pipe forces. • Cover depth, backfill stiffness, and the compaction efforts significantly affect the results. The Canadian Highway Bridge Design Code (CHBDC), the American Association of State Highway and Transportation Officials (AASHTO) and the Swedish Design Manual (SDM) are regarded as fundamental manuals for the design of flexible corrugated metal pipes. However, these manuals do not consider properly several factors that may affect the soil-structure interaction, such as the backfill soil stiffness, the pipe burial depth, the effect of compaction loads, and the trench geometry, including the trench width and the slope of the side of the excavation. To examine these factors, this paper utilizes a detailed finite element model of a flexible corrugated metal arch pipe. The model was developed and validated by using a field case study in Sweden. In a comprehensive parametric study, the numerical analysis and the empirical methods are used to investigate the applicability and accuracy of these methods for estimating the interaction behaviour of flexible culverts installed in semi-shallow and shallow trenches. [ABSTRACT FROM AUTHOR]

The Canadian Highway Bridge Design Code (CHBDC) provides formulas for determining the live load distribution factors for composite slab-on-girder bridges. These formulas were developed by neglecting the contribution of secondary elements such as lateral bracing in bridges, leading to conservative design in some cases and unsafe design in others. This paper presents a practical-design-oriented parametric study, using three-dimensional (3D) finite-element modeling, to investigate the live load distribution factors of composite braces steel I-girder bridges under CHBDC truck loading conditions at ultimate, serviceability and fatigue limit states. The key parameters considered in this study included girder stiffness and spacing, span length, number of girders, and number of design lanes. The comparison of results suggested that the CHBDC equations underestimate the girder moments for the 15 m spans and overestimates the response for greater spans. On the other hand, CHBDC generally overestimates the shear distribution factors, with significant difference observed at fatigue limit state. Based on the database generated from this study, a set of empirical expressions were developed for the moment and shear distribution factors for rational prediction of the girder design moment and shear force. A design example is presented to illustrate the use of the developed equations. [ABSTRACT FROM AUTHOR]

A novel glass fibre-reinforced polymer (GFRP) bridge girder was developed and implemented in a bridge superstructure as the result of the domestic R&D project. The novel GFRP girder consists of a shell with trapezoidal cross-section and a sandwich deck slab, both acting compositely owing to structural bonding. Before superstructure implementation, a test specimen fabricated as a full-scale prototype of the GFRP bridge girder was subjected to a series of static and dynamic tests to evaluate its structural performance and to verify design predictions and to check relevant code requirements. This paper presents a prototype GFRP girder itself and the selected results of an experimental study on its stiffness, strength, ultimate capacity and failure mode, global factors of safety against failure and dynamic characteristics. The output of testing confirmed that the proposed GFRP bridge girder has an appropriate structural performance and fulfils the design assumptions and relevant standard requirements to be considered in an actual road bridge design. [ABSTRACT FROM AUTHOR]

This paper investigated the influence of atypical agricultural vehicle parameters on girder distribution factors (GDFs) for two simply supported steel-concrete composite bridges located on secondary roads in the United States. As part of the parametric investigation, field measurements were performed on the bridges under the passage of full-scale agricultural vehicles along each bridge centerline. Strain data obtained from field tests were used to determine field GDFs. Both field data and GDFs were used to calibrate a finite element model of the bridge. Data from over in-use one hundred agricultural vehicles were collected, and then each vehicle was applied to the model to compute analytical GDFs. These vehicles were analytically and statistically investigated to determine the sensitivity of GDFs to vehicle parameters, including maximum vehicle axle load, gage width, and spacing distributions. Based upon field strain investigation for the two bridges, the responses of the central girders were greater than those of the exterior girders, resulting in greater field GDFs for central girders than those of the exterior girders. Results also indicated from the sensitivity study that each girder had different levels of correlation between GDFs and single vehicle parameters. [ABSTRACT FROM AUTHOR]