Highway Bridge Superstructures Research Articles

On the effects of modified lane configuration due to construction works on bridge loading

Construction works are frequently recurring events within highway networks, temporarily altering the characteristics of the traffic flow and hence of the bridge loading process. Consequently, highway bridge superstructures usually carrying unidirectional traffic might have to face modified configurations, with possibly altered lane widths and transverse lane positions, or even an increased number of lanes and the occurrence of bidirectional traffic flow. While usually covering only short periods compared to the average service life of a bridge, such scenarios might represent extreme loading situations, potentially dominating the traffic loading process. Therefore, their consideration and accurate modeling in the course of traffic load assessment and development of object-specific traffic load models are of utmost importance. The presented study analyzes data from bridge monitoring along federal highway A92 in Southern Germany. The data covers standard and different modified lane configurations due to construction works. Besides analyzing the effects on traffic flow characteristics and resulting occurrence rates of multiple truck presence on the bridge, the consequences for load effects and their extreme value behavior are also evaluated. The findings support verification of related code background works and can serve as base and guidance for future research efforts on bridge load modeling in this context.

Construction Points of Prestressed Concrete Beam of Highway Bridge Superstructure

Construction Points of Prestressed Concrete Beam of Highway Bridge Superstructure

Longitudinal Joints between Deck Bulb Tee Girders Made with Nonproprietary Ultra-High-Performance Concrete

Abstract Highway bridge superstructures may be built using only precast concrete elements, such as deck bulb tees (DBTs). Formerly flange connections between those members have been made with welde...

Characterization of hydrodynamic properties from free vibration tests of a large-scale bridge model

To accurately predict the dynamic response of a structure subjected to fluid induced loading, a thorough understanding of the dynamic properties (mass, stiffness, and damping) and associated interactions is required. Limited data are available to characterize dynamic fluid–structure interactions. Data are particularly limited for large-scale and flexible structural models. This article reports the results of the first free vibration tests of a dynamic large-scale laboratory highway bridge superstructure model. The dynamic response characteristics of the model were extracted and analyzed from free vibration tests under varying levels of water submersion and for different horizontal substructure flexibilities. The nature of the damping response was identified based on the empirically measured logarithmic decrements of the model’s free vibration displacement amplitudes, and a suitable equation of motion (EOM) was subsequently developed. Using the classical fourth-order Runge–Kutta method, the EOM was solved for the different test trials and the dynamic properties of the model were obtained through an optimization approach. The concept of added mass was introduced to explain the observed decrease in natural frequency with increasing levels of water submersion. Finally, added mass factor was computed for the case where the water level was even with the top of the bridge superstructure model. This study provides a suitable EOM needed for numerical simulations of this and similar models that study fluid–structure interaction and also provides a methodology for establishing the structural dynamic properties of generalized hydrodynamic analytical models.

Strength and Stiffness Behavior of Earthquake Resistant Pedestrian LVL Timber Bridge

A bridge is a structure which is used to connect two areas separate by obstacles. The environmental damage caused a number of reductions in the production of timber, and by that, the LVL timber which is a high quality processed or engineered timber is chosen. This research determined the design of the timber bridge structure for pedestrian with simple beam type and earthquake resistant. The load in this bridge is referring to the SNI 1725:2016 and SNI 2833:2008, the design of the girder and the connection is referring to SNI 7973:2013, and the deflection is referring to the LFRD for Highway Bridge Superstructures. The timber bridge is designed to have a span of 10 metres long and 3 metres wide. The modeling and designing of the wooden bridge are using an application called SAP2000 based on finite element analysis. Result obtained from this research indicated that the longitudinal dimension of the girder is 360 mm x 630 mm and the cross sectional dimension is 180 mm x 270 mm. The number of bolts and lock screws needed on the connection among the longitudinal girders are 40 pieces, between the longitudinal girders and the cross sectional girders is three pieces, and between the railing and the slab are two pieces. Based on the stiffness review, the results showed that the bridge deflection that occurred was lower than the permit deflection

Deterioration models for prediction of remaining useful life of timber and concrete bridges: A review

Abstract Bridge deterioration models are used for prioritization and maintenance of bridges. These models can be broadly classified as deterministic and stochastic models. There are mechanistic models (or physical models) as well as Artificial Intelligence (AI)-based models, each of which can be stochastic or deterministic in nature. Even though there are several existing deterioration models, state-based stochastic Markov chain-based model is widely employed in bridge management programs. This paper presents a critical review of different bridge deterioration models highlighting the advantages and limitations of each model. The models are applied to some case studies of timber superstructure and concrete bridge decks. Examples are illustrated for arriving at bridge deterioration models using deterministic, stochastic and Artificial Neural Network (ANN)-based models based on National Bridge Inventory (NBI) data. The first example is based on deterministic model and the second on stochastic model. The deterministic model uses the NBI records for the years 1992–2012, while the stochastic model uses the NBI records for one year (2011–2012). The stochastic model is state-based Markov chain model developed using Transition Probability Matrix (TPM) obtained by Percentage Prediction Method (PPM). The two deterioration models (i.e., deterministic and stochastic models) are applied to timber highway bridge superstructure using NBI condition data for bridges in Florida, Georgia, South Carolina and North Carolina. The illustrated examples show that the deterministic model provides higher accuracy in the predicted condition value than the stochastic Markov chain-based model. If the model is developed based on average of transition probabilities considering the data for the period 1992 to 2012, the prediction accuracy of stochastic model will improve. Proper data filtering of condition records aids in improving the accuracy of the deterministic models. The third example illustrates the ANN-based deterioration model for reinforced concrete bridge decks in Florida based on the NBI condition data for the years 1992–2012. The training set accuracy and testing set accuracy in the ANN model are found to be 91% and 88% respectively. The trained model is utilized to generate missing condition data to fill the gaps due to irregular inspections of concrete bridges. This paper also discusses scope for future research on bridge deterioration modeling.

Evaluation of the Increased Dynamic Effects on the Highway Bridge Superstructure

Dynamic properties of the bridge superstructure vary depending on many characteristics of the bridge and the loading conditions. In this paper, maximum Dynamic Amplification Factor was calculated for six different types of typical pre-stressed concrete beam bridges. It showed that each type of bridge with similar loading has a different range of Dynamic Amplification Factor. At the same time, every recently built bridge has different geometry and design load. Hence, it is difficult to determine a characteristic value of Dynamic Amplification Factor for the similar type of structures. By using fullscale dynamic and static bridge tests, it is possible to determine the necessary characteristics which show possibly high Dynamic Amplification Factor. This factor indicates if it is necessary to make a full-scale bridge dynamic analysis. It was found that those characteristics are natural frequency (first mode), damping ratio, relative deflection, and span and depth ratio. Obtained results from tests show a range of values for each of the characteristic. These ranges were analysed for reinforced concrete slab and pre-stressed concrete slab, and girder bridges.

Efficient construction of the motorway and highway bridge superstructure (experimental studies)

The design of the span structure of the bridge was presented. Its structure was formed by the creation of a composite steel and concrete element consisting spatial steel perforated boxlike-section blocks, a system of shear links of a special type and a monolithic reinforced concrete slab containing inside emptiness-formers The novelty of the design and methods of its creation predetermined the need for experimental testing. It was implemented in full-scale conditions and had, in addition to research, acceptance nature. In this connection, the article presents the results of tests of the composite steel and concrete structure of the superstructure of the bridge over Sukhoy Torets in Barvenkovo. The nature of its deformation under the static and dynamic loads is shown. During the tests, the components of the stress-strain state were determined at the distinguished points of the structure, fixed under static load. The amplitude and frequency response of the bridge unit were established for various dynamic impact options. Based on the obtained data, the structural resistance features under load impacts was analyzed, the design model of the bridge was verified, and the compliance of the accepted design parameters with the limitations of the applicable reference documents was confirmed.

KL-510 하중에 의한 강판형교의 동적응답

본 연구에서는 교량의 노면조도 및 교량과 차량 사이의 상호작용을 고려한 수치해석방법을 사용하여 도로교설계기준에 규정된 표준트럭 하중인 KL-510에 의한 강판형교의 동적응답을 연구하였다. 대상교량은 건설부에서 제정한 "도로교 상부구조 표준도"에 수록되어 있는 지간이 20m, 30m와 40m인 단순 강판형교를 사용하고. "보통의 도로"에 대하여 생성시킨 10개의 노면조도를 사용하였다. 차량은 5축 트랙터-트레일러인 표준트럭하중 KL-510을 3차원 차량으로 모델링하고, 교량은 주형을 보요소로, 콘크리트 바닥판은 쉘요소로, 주형과 콘크리트 바닥판 사이는 Rigid Link를 사용하여 3차원으로 모델링하였다. 이와 같은 노면조도 및 차량을 사용하여 강판형교의 충격계수와 DLA를 구하고 각국의 설계기준과 비교 검토하였다. Dynamic response of steel plate girder bridges by KL-510 design truck in KHBDC considering the road surface roughness of bridges and bridge-vehicle interaction is investigated. Simply supported steel plate girder bridges with span length of 20m, 30m, and 40m from "Standard Highway Bridge Superstructure" published by the Korean Ministry of Construction are used for a bridge model, and ten sets of the road surface roughness of bridge deck are generated from power spectral density (PSD) function by assuming the roadway as "Average Road". A three dimensionally modeled 5-axle tractor-trailer with its gross weight, which is the same as that of KL-510 design truck, is used for dynamic analysis. For the finite element modeling of superstructure, beam element for the main girder, shell element for the concrete deck, and rigid link between main girder and concrete deck are used. Impact factor and DLA of steel plate girder bridges for different span are calculated by the proposed numerical analysis model and compared with those specified by several bridge codes.

Influences of Climate Change on Reliability of Bridge Superstructure

Global climate change, including climate deterioration and extreme weather events, has serious impacts on reliability of bridge superstructure. Global warming and increasing velocity of wind associate with the increase of CO2 level play a dominate role in reliability degradation. For the highway bridge in offshore environment, a main factor of reinforcing steel corrosion is the invasion of chloride ion, which can cause durable damage of the structures. Moreover, temperature rises will increase corrosion rates. In addition, changes in maximum wind speeds may increase expected wind loads on bridge structures. This paper develops a reliability analysis model to assess the reliability degradation of the highway bridge superstructure under (i) base case, (ii) temperature rising case, (iii) wind speed changing case, and (iv) combination of case (ii) and case (iii). The process is illustrated by studying the reliability of a offshore highway bridge using simplified models of the structure. It is demonstrated that the reliability degradation will be greatly accelerated taking account of climate change. The life expectancy of the structure will be 10 years and 70 years lower than base case if the target reliability is 4.5.

Redundancy and robustness of highway bridge superstructures and substructures

Major advances have been recently achieved in developing methodologies for the structural analysis of cascading failures and in understanding the behaviour of different types of systems under suddenly applied extreme loads. Yet, a main issue related to defining objective measures of redundancy and quantifying the levels of redundancy that exist in structural systems remains vastly unresolved. This paper reviews the work done by the authors and their colleagues on the quantification of system redundancy of typical highway bridges and reassesses previously made proposals for including system redundancy and robustness during the structural design and safety evaluation of bridge superstructure and substructure systems. These proposals, which are based on system reliability principles, consider structural system safety, system redundancy and system robustness in comparison to member safety, and account for the uncertainties associated with determining member and system strengths as well as future loads in a consistent and rational manner.

Seismic Design and Ductility Evaluation of Thin-Walled Steel Bridge Piers of Box Sections

This paper deals with seismic design and ductility evaluation of thin-walled steel bridge piers of box sections supporting highway bridge superstructures. The basic characteristics of the thin-walled steel box section structures are noted. A seismic design method for ultimate strength and ductility evaluation of thin-walled steel bridge piers of box sections is presented. The application of the method is demonstrated by comparing the computed strength and ductility of some bridge piers with test results. The method is applicable to both the design of new, and the retrofitting of existing, thin-walled steel bridge piers of box sections. The effects of some important parameters, such as width-to-thickness ratio, column slenderness ratio, and residual stress, on the ultimate strength and ductility of thin-walled steel bridge piers of box sections are presented and discussed.

System Factors for Highway Bridge Superstructures

Although traditional methods of bridge structural design proportion each member separately, the members do not behave independently but interact to form a single structural system. To account for overall system safety during the design process, the current AASHTO load and resistance factor design (LRFD) specifications (AASHTO LRFD Bridge Design Specifications, 2002) provide a load modifier factor, η, which explicitly accounts for the effects of ductility, redundancy, and operational importance. In the absence of precise information, the values used for the load modifiers are assigned subjectively. The results of a research project funded by NCHRP that led to the development of objective measures of redundancy and a method that uses system factors, Φs, during the design and load capacity evaluation process to account for the system's reserve strength are summarized. A set of proposed system factors was calibrated to provide bridges with adequate levels of overall safety and system reliability. Nonredundant...

Rehabilitation of Bridge Superstructures via the Addition of Girder Lines. I: Theoretical Considerations

A companion paper reported on theoretical considerations associated with adding girder lines to rehabilitate highway bridge decks and superstructures. This article reports on practical, construction, and cost considerations associated with the addition of girder lines rehabilitation strategy. Results of the investigation indicate that adding longitudinal girders between the existing girders is a viable bridge superstructure rehabilitation strategy. The two primary merits of the strategy are (1) most of the work can be performed from the underside of the bridge, thus minimizing interference with traffic; and (2) the strategy strengthens and stiffens the deck/superstructure and, therefore, should significantly prolong the remaining service life of the existing girders and deck. The greatest drawback to the adding girder lines strategy is its high initial cost. Because of this high cost, the strategy is not recommended except in special cases.

Construction of Fiber-Reinforced Plastic Modular Decks for Highway Bridges

Fiber-reinforced polymer (FRP) composite materials have shown great potential as alternative bridge construction materials to conventional materials such as steel and concrete. This is especially valid in the field of repair and rehabilitation of existing bridges as well as in new bridge construction. The acceptance of composites in the highway bridge industry is mainly due to their superior properties such as high strength, durability, corrosion resistance, and fatigue resistance. Moreover, FRPs are well suited for mass production of structural shapes because of their high strength-to-weight ratios, which has resulted in the rapid installation of FRP modular decks on highway bridges. Details related to the construction of FRP modular decks as replacements on existing highway bridge superstructures are provided. In addition, details on shipping, handling, erection, assembly, deck-to-deck connections, deck-to-stringer connections, joints, and wearing surfaces are discussed.

Effect of vertical support on highway bridge superstructures

A Fourier series expansion is used to obtain the deflection, moment, shear, velocity, and acceleration expressions for a multispan highway bridge superstructure under the effects of vertical support motion. These expressions are used in computer programs that compute the maximum values along the bridge span. The formulation is also used to show the feasibility of creating nondimensionalized design aids that may be used in industry. A finite element analysis is used to help verify the results.

Final Report on Specifications for Bridge Design and Construction for Design and Construction of Steel Highway Bridge Superstructures

These specifications cover the design of fixed span bridges and require first-class design, material, and workmanship, subject to the approval of the Engineer.