Bridge Superstructure Research Articles

Large displacement behaviour of GRS bridge abutments under passive push

Many bridge abutments suffered failures due to large lateral deformations due to seismic shaking. During earthquakes, bridge abutments restrict the bridge deck's intrusion towards the backfill soil by generating passive earth pressure, which provides resistance to lateral deformation. As a result, the backfill takes the earthquake induced inertial forces transmitted from the bridge superstructure through abutment. Now a days, GRS bridge abutments are widely used due to their many advantages. In this paper, the behaviour of these GRS bridge abutments under large displacements such as 1 m lateral push into the soil due to the impact of bridge deck has been analysed and studied. It is observed that the GRS abutments with longer geogrids are observed to show better passive resistance.

Calculation method steel reinforced concrete continuous bridge spans with two reinforced concrete slabs on the effect of concrete shrinkage

The article is considered calculation method steel reinforced concrete continuous bridge spans with two reinforced concrete slabs on the effect of concrete shrinkage. For long-term processes that must be considered when calculating the span structures of bridges, besides creep, concrete shrinkage applies. Object of study: composite steel and concrete span beam bridge with two reinforced concrete slabs. Purpose: to develop a calculation method the cross section steel reinforced concrete bridges with two reinforced concrete slabs on the effect of concrete shrinkage considering concrete creep. Continuous spans of steel reinforced concrete bridges with two reinforced concrete slabs over intermediate supports much more economically, in terms of metal consumption, compared to steel reinforced concrete bridges with one concrete slab. Cross section of a reinforced reinforced concrete beam consists of a steel part that combined with two reinforced concrete slabs. The article presents the results of the calculation of continuous steel-concrete superstructure of a road bridge with two reinforced concrete slabs by the above method.

Thermal Method in the Control of Fatigue Cracks in Welded Bridge Superstructures

The purpose of the work is the use of infrared thermography in examinations and diagnostics of bridges to detect fatigue cracks. The research methods accepted laboratory and natural tests. The configuration of samples (cantilever sheet samples reinforced with stiffeners) and loading conditions corresponded to the actual operating conditions of the bridge beams. As a result of laboratory experiments, the process of metal self-heating around the fatigue crack tips was shown, as well as the general process of temperature change across the entire field of the sample. Also, studies were conducted on the process of self-heating of metal on operated bridge designs with fatigue cracks. The results of laboratory and field studies on welded superstructures are presented, as well as the applied algorithms for the software processing of thermal images are described. Studies have shown the applicability of infrared thermography to identify and assess the degree of development of fatigue cracks in welded superstructures of railway bridges.

Fatigue life analysis of laminated elastomeric bearing pad

The elastomeric bearing pads playing an important role by transforming the loads from bridge superstructure to its substructure. The fatigue life estimation of these elements is necessary to avoid any problems resulting from deterioration of such elements. To do so, the current study is devoted to develop a three-dimensional model for steel-laminated bearing pad subjected to different designated applied loads. The Ogden model, one of the built-in constitutive models in ABAQUS software, was used to fit the experimental load-deformation curve and to obtain the coefficients of the rubber material used in the pad to feed the ABAQUS software. The pad was modelled with elements C3D8R, C3D8RH, and M3D4R to represent the steel, rubber, and rubber skin respectively. Four loads with three frequencies for each load were selected to applied on modelled pad. Fe-safe, one of ABAQUS software package, was used to find the fatigue life for modelled pad. The results showed a good agreement with previous experimental studies on this field.

Automated design of the railway bridge structure

This paper presents the design and calculations of bridge structures using modern computer technology. They provide the special capabilities necessary for the design of bridges, for example, the construction of influence lines for calculating moving loads, for calculating nodal interfaces, for checking local stability, for calculating the thermal stress state of supports, etc. The main purpose of the survey of the bridge structures was to obtain the initial data in accordance with GOST-v and SNiP-v for calculating the carrying capacity of the bridge superstructure, assessing the technical condition and developing recommendations for its further operation.

Critical Aspects in Design and Construction of Open Type Shallow Highway Girders Across Railways

A highway bridge across railways in-lieu of the level crossing will surely be smoothening the road traffic and the rail traffic. Hence, it is essential to bridge across the railways at all the level crossing locations in a developing country. Due to the introduction of a bridge across a busy railway track, the necessity to negotiate the level difference happens. This level difference is more with the usage of the conventional type of girders. By this, the delay of the project due to land acquisition is considerable. The most suitable superstructure for such highway bridge is the deck with shallow open type pre-stressed girders. When multiple shallow, open-type girders are placed adjacently and integrated with a deck slab above these, the load distribution and sharing between girders are to be refined based on experimental studies and authors discussed the same within this paper. An experimental study on two Double-T cross-section pre-stressed model girders and deck assembly revealed the structural behaviour between girders. The results from the two-point load testing helped in developing various design methodologies in this study. An escalation of 17% in the design forces need to be considered on the results obtaining from the grillage analysis, to cater the unbalanced forces on the individual web of the open-type girder, during the eccentric loading condition. The Authors elaborated the design of shear friction reinforcement. The self-managing capacity of the spreading tendency of the webs of this type of girders is due to the counteracting of radial pressure generated from the pre-stressing force. The critical aspects of construction also dealt with in this paper without which the usage of open-type girders with ends closed cannot be encouraged. The authors developed conceptual designs for the removable internal shutter, launching scheme and demolishing of the bridge superstructure, in this study. The dismantling of the bridge is a rare requirement arises only when the number of track increases. The reuse of girder-deck assembly is also found possible and suggested in this paper.

Experimental study on static and dynamic performance of a novel GFRP bridge girder

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.

Performance of fiber-reinforced concrete link slabs with embedded steel and GFRP rebars

Expansion joints in bridge superstructures are often difficult to maintain, leading to the problems associated with water leakage and debris accumulation. As a potential solution, link slabs can be placed at the expansion joints, providing a continuous deck system. Despite the promise of such a system, there have been standing questions on the materials of choice and structural configurations appropriate for link slabs, especially in their transition zone from the bridge deck to their debonded region. This motivated the current study to investigate various reinforcement alternatives using full-scale laboratory tests and numerical simulations. To achieve a satisfactory crack resistance, a fiber-reinforced concrete (FRC) mixture was developed for the tested link slabs. In addition, two rebar alternatives, i.e., steel and GFRP rebars, were evaluated to ensure a proper transfer of stresses induced by negative bending moments (due to continuity) and to limit the width of cracks on the top surface of the link slabs, where they are directly exposed to water and deleterious agents. The full-scale performance was examined under increasing vertical loads applied to the midpoint of two individual spans connected by a link slab. This included an investigation of various structural response measures, such as strains in the FRC and embedded rebars. The study was then extended by performing a set of finite-element simulations to understand the effects of reinforcement details. The outcome of this study provided holistic information on how flexible link slabs can be utilized for jointless bridge superstructures, addressing the concerns regarding their performance and durability.

Study of wave forces acting on the box-girder superstructure of coastal bridges in the submerged condition based on potential flow theory

The box-girder superstructure of coastal bridges is vulnerable to wave-induced damage in the case of small clearances. The analytical method for estimating the wave forces on the box-girder superstructure of coastal bridges is proposed based on the potential flow theory in this paper. The two-dimension problem of the box-girder superstructure under the wave action is defined with some necessary simplifications first. Then, the analytical solutions are solved by the eigenfunction matching method, and the wave force on the submerged box-girder superstructure is calculated using the Bernoulli principle. After validating the accuracy of the proposed method by previous calculations and the experimental test, the influences of the girder type and structural configuration on the wave forces of submerged box-girder are conducted using the proposed analytical method. The results show that the girder type has a significant effect on the wave forces of the submerged superstructure, and the influence of various structural parameters should be considered comprehensively in the structural safety design under wave actions. The results of the present study can provide a useful reference for the estimation of wave forces and the structural design of the box-girder superstructure of coastal bridges.

Wave characteristics and spectrum for Pingtan Strait Bridge location

In order to obtain the wave forces on the substructure and superstructure of the sea-crossing bridge, this paper develops a systematic series of wave spectra covering a variety of spectral shapes observed in the bridge site area of Pingtan Strait Bridge. Error identification of wave data and data reconstruction using the orthogonal matching pursuit of compressive sensing algorithm are conducted to obtain the stable and accurate water level data firstly. The characteristic of the wave is then evaluated, and the joint distribution of significant wave height and average wave period is investigated using copula models. A family of wave spectra is proposed to represent a set of 7084 spectra measured at the 6# platform of the Pingtan Strait bridge site. Analytical results show that the proposed wave spectra family (Pingtan spectra) can represent the realistic wave spectra, and the Pingtan spectra characteristic can also reflect the diversity and randomness of the realistic wave spectrum. Application of the wave spectra suggests using the proposed spectra to calculate the wave force on the structure of the Pingtan Strait Bridge location.

Research on Application of RPC Materials in Urban Pedestrian Bridge Reconstruction

Aiming at the characteristics of poor corrosion resistance, high maintenance frequency and high cost of steel box girder pedestrian bridge structure, and the traditional concrete is thick and moderate in strength, this paper proposes a method to apply reactive powder concrete RPC to the existing pedestrian bridge deck and uses steel-RPC composite box girder as the bridge superstructure. Based on the research on the RPC material and the related performance of its components, the feasibility and reliability of RPC applied to beam-slab composite members are verified. By comparing steel-RPC composite box girder, steel box girder, and steel-general concrete composite box girder, it is found that steel-RPC composite box girder is superior in terms of mechanical performance, economic evaluation, and aesthetics. The research shows that the steel-RPC composite box girder is more suitable for the steel box girder pedestrian bridge reconstruction project and the new pedestrian bridge project across urban roads.

Evaluation of Impact Resistance for Derailment Containment Provision Using Drop Weight Test

In Korea, to prepare for unexpected accidents caused by human errors and natural disasters that cannot be completely prevented, a protective wall (a type of side-structure) against derailed trains has been installed on high-speed railway bridges as one of the physical measures to mitigate the associated damage. However, taking the geometric aspects of a domestic railway bridge's super structure into consideration, such a protective wall is not appropriate, and the corresponding protective performance does not provide adequate security. Hence, a protective wall named Derailment Containment Provision (DCP) was newly developed and installed in the track gauge. In this study, to evaluate the impact resistance of the newly developed DCP, a drop weight experiment was conducted, and the impact behavior corresponding to a specific impact energy was analyzed.

Calibration and parametric investigation of integral abutment bridges

Integral abutment bridges (IABs) are a special type of bridges that are built free of joints on the superstructure to overcome the undesirable consequences associated with conventional jointed bridges. Despite of the proven advantages of IABs, no consensus exists among bridge engineers about design guidelines. This paper presents a parametric study validated to a field monitored concrete IAB using a three-dimensional finite-element model to study the parameters that affects the bridge response. Bridge length, pile size and orientation, and soil type were included in the study. Bridge components were simulated using 3D solid elements for best reflection of the real behavior of the IAB. Nonlinear p-y method was employed to model soil-pile and soil-abutment interactions. Several shrinkage models, earth pressure theories and temperature distribution across the bridge superstructure were considered in simulating the field response of the IAB. The outcomes of the calibration process were utilized in building sound models for the parametric study. The soil stiffness around the pile was found to has more impact than the pile orientation on the pile displacement. Pile stresses were found to be proportional to the soil stiffness and inversely proportional to the pile stiffness. Moreover, the maximum stresses occurred within the middle segment of the pile rather than the pile-abutment interface due to apparent abutment rotation. The study promotes understanding of important facts which could assist in a better IAB design.

Experimental Characterization of Static Behavior of a New GFRP–Metal Space Truss Deployable Bridge: Comparative Case Study

A new glass fiber-reinforced-polymer (GFRP)–metal box-truss composite girder was developed for use in lightweight deployable vehicular bridges with favorable torsional resistance for large spans. This paper describes the experimental characterization of the static behavior of the latest structure characterized by a closed cross section, with a comparative study on an early version having an open cross section. The structural form of the new structure differed considerably from that of the early version. Nondestructive tests with symmetrical and unsymmetrical static loadings were conducted on a newly fabricated prototype to identify the characteristic flexural and torsional performances of the new structure. Additionally, a comparative evaluation of the experimental behavior in terms of load–displacement and load–strain responses was conducted between the new structure and the early version. Favorable results demonstrated that the new structure enabled satisfactory static performances in terms of deployable bridge applications. The resulting comparisons indicated that the new structure featured a flexural resistance identical to that of the early version. However, the addition of lower plane-truss transverse braces in the new design significantly increased the torsional resistance of the space truss system. The overall torsional rigidity of the new structure approximately corresponded to 2.36 times that of the early version. Moreover, the stress state in the extrusion-type GFRP tubular elements of the space truss system was significantly improved. Compared to the early version, the latest structure is more appropriate for use in the primary load-carrying superstructures of large-span deployable bridges under critical unsymmetrical service loading conditions.

Chloride Transport in Cracked Concrete Subjected to Wetting – Drying Cycles: Numerical Simulations and Measurements on Bridges Exposed to De-Icing Salts

Although many models for service life predictions have been developed, their application to existing bridges is still not at a satisfactory level. The here presented coupled 3D chemo-hygro-thermo mechanical (CHTM) model can realistically simulate both corrosion phases: initiation and propagation. The focus of this research is the transport processes in cracked and un-cracked concrete before reinforcement depassivation. Realistic environmental conditions with the surface water and chloride contents variable in time are simulated based on the meteorological data for a mountain region where case studies bridges are located. Application of the large quantities of de-icing salts in combination with the poorly designed and executed details resulted in a high chloride content in concrete of the superstructure of both bridges: at the reinforcement level chloride content in cracked concrete elements exceeds the threshold value up to 10 times. Numerical results match well with the chloride content measured on the bridges after 11 and 14 years of service. Accounting for the realistic environmental conditions (wetting-drying cycles, application of de-icing salts only in the winter season, etc.) in the numerical simulations results in the continuous transport processes in concrete and higher chloride content in deeper concrete layers as opposed to the finite element models with the constant boundary conditions.

Conformity assessment of two orthotropic steel deck bridges in Bulgaria according to present requirements

Two orthotropic steel deck (OSD) bridges along “Hemus” highway in Republic of Bulgaria are discussed in the paper. They are built at 1985 and are in exploitation over 30 years up to present times. The first of the bridge superstructures is with closed section trapezoidal longitudinal ribs of the OSD and steel plated main girders with 72,45 m span. The second bridge superstructure is with open type section longitudinal ribs of the OSD and steel box main girder with 162m span. Visual inspection and some measurements are performed for evaluation of the overall condition of these bridges. It must be mention that the traffic has considerably increased. Some checks for fatigue for the second bridge are performed in accordance with Eurocode. The condition in respect to fatigue behaviour in accordance with the used structural details in the OSD and the prescriptions of the present design standards is analysed and discussed.

TINJAUAN GAYA TSUNAMI PADA JEMBATAN KRUENG RABA

Aceh Province is located in one of the earth's fault lines in Indonesia, which is an area prone to earthquakes and the potential for a tsunami disaster. Therefore, any planning of structures located on the coast must consider the potential for a tsunami to obtain a strong structure to withstand the forces affected by the tsunami. During the 2004 tsunami, many bridges were carried away by the tsunami. Both bridges made of concrete, as well as steel frame bridges, such as the Krueng Raba steel frame bridge, Lhoknga, the Krueng No bridge, the Meunasah Kulam bridge, and several other bridges. This study aims to analyze and calculate the force and load effects of the tsunami on the structure of one of these bridges, namely the Krueng Raba steel frame bridge, Lhoknga. The force and load of the tsunami effect (Ts) will be analyzed by adopting the Guidelines for Design of Structures for Vertical Evacuation from Tsunamis, 2012, namely: (1) hydrostatic force; (2) buoyant forces; (3) hydrodynamic forces; (4) impulsive forces; (5) debris impact forces; (6) debris damming forces; (7) lift force; and (8) additional gravity load from water retained on the bridge floor. From the results of this study, it is shown that each of the tsunami forces acting on the crew-raba Lhoknga bridge at the minimum tsunami height variable, 11 meters, which is the initial height of the tsunami touching the bridge's superstructure are: 94.866 KN hydrodynamic force; 142,299 KN thrust; 133,810 KN debris impact force; 14,244 KN debris dam force, and 34,018 KN lift force. Meanwhile, the maximum tsunami height variable, 25 meters, is 24634.934 KN hydrodynamic force; 36952,400 KN thrust; 720,591 KN collision force; 3698,939 KN debris blocking force; and 986,519 KN lift styles. The results of the analysis using computational methods, by inputting the magnitude of the tsunami forces to the bridge model, it can be seen that the ability of the Krueng Raba, Lhoknga steel frame bridge to withstand the forces and loads caused by the tsunami only up to a height of 14 meters.

Running Safety of a High-Speed Train within a Bridge Zone

This paper describes the issue of validity of running safety criterion on high-speed railways (HSR). In this research, the 2D model of ‘car–track–bridge’ system is used. A feature of HSR is the practical reaching of the critical speeds that cause resonance of bridge superstructures. The Eurocode establishes the limit of bridge superstructure acceleration below 5[Formula: see text]m/s2 in case of nonballasted track. This limit does not suit in certain conditions such as resonance of the superstructure that is permitted in Eurocode. In this case, there is no correlation between acceleration limit and firm wheel–rail contact. The numerical analysis shows repeated wheel lift-off during train passing a bridge zone. It is resonance of the bridge deck that causes this effect because without resonance, the running train is safe. Lower damping in nonballasted track increases resonant vibration influence.

Parametric Study on the Structural Behavior and Failure Mechanism of Skewed Inverted-T Bent Caps

Abstract In the past several decades, the inverted-T bent caps (ITBCs) have been frequently used as an innovative type of bridge superstructure worldwide. In some specimens, the bent caps have to b...

Force-displacement response of bridge abutments under passive push

Many bridge abutments have suffered failures due to pounding of bridge superstructure elements during earthquakes. Due to pounding of the bridge deck, the bridge abutment undergoes translation and rotation. The lateral translation of the bridge deck towards the abutment is resisted by the abutments through mobilisation of passive earth pressure. The passive earth pressure plays an important role in many geotechnical problems. In the conventional design practices, usage of lesser magnitude of passive pressures is considered to be conservative. However, it is not so under all circumstances. In this paper, various analytical ways of obtaining the force–displacement response of bridge abutments from different seismic design guidelines are reviewed. From the literature review, it has been observed that the guidelines for obtaining the force–displacement response of the GRS abutments resting on Pile foundations are yet to be developed.