Segmental Girder Research Articles

Accelerated construction and geometry control of cable-stayed bridge: cable crane method

Mountainous regions with rugged terrain, steep valleys and restricted access to roads and rivers present distinctive challenges for segmented erection of cable-stayed bridges (CSBs). In recent years, the cable crane method (CCM) has emerged as an innovative solution for CSB construction to address the difficulties associated with vertically lifting and horizontally delivering girder segments in such challenging environments. However, integrating the CCM with a CSB introduces a coupling effect, significantly complicating the control of bridge geometry. In this work, the accelerated construction and geometry control for CSBs employing the CCM in mountainous regions were systematically studied. The characteristics of 1521 bridges in mountainous regions were investigated, followed by a numerical analysis of geometry control and field measurements of as-built geometries, forces and ambient conditions during construction. Critical techniques for CSB construction using the CCM are also clarified. The mechanical behaviour of a bridge during construction was comprehensively evaluated to improve geometry control. The numerical results were validated through field measurements, offering valuable insights for future CSB practices using the novel CCM.

A Review on Need of Effective Construction Management for Box Girder Segment Erection Techniques by Under Slung

India is creating nation due to which foundation development massively expanding day by day. As result of advancement keen arrangement required for cites infrastructural development, all of which require to be coordinates with open transport. Different inquires about and improvement are held by analysts to discover financial and time sparing technic of developments. Precast concrete is one of those investigates. The support of precast strategy in development has expanded around the world within the final few decades. This strategy of superstructure casting in urban ventures proposal numerous points of interest like diminished costs, decreased development time, decreased natural impacts, and diminished support of activity. The beneath thrown strategy for propelling box support sections stands as an inventive and effective procedure in advanced bridge development. This strategy includes suspending pre-cast box support sections from transitory underpins underneath the completed parcels of the bridge and incrementally advancing these sections to make the superstructure. The ponder will investigates the complexities and points of interest of this procedure, centering on its execution .To study the part of the transitory pre-stressing framework within the cantilever gathering prepare of the precast section box support bridge, . It is additionally critical the amid the development stage of appropriate usage of administration framework to realize the security quality and opportune completion of ventures, In this paper the need of need of effective construction management is analyzed also the effective construction management is helpful for box segment erection techniques under slag will review from various research papers and literature

Forward iterative algorithm for fabrication geometry of steel girders in cable-stayed bridges

This paper proposes a forward iterative algorithm designed for determining the fabrication geometry of the steel girder in cable-stayed bridges during the segment installation process. The expression of fabrication geometry control parameters and geometric dimensions for steel girder fabrication is deduced based on the installation geometry. Based on the equivalent plane algorithm for spatial stay cables, this paper establishes a forward iterative algorithm to simulate the construction process of cable-stayed bridges, employing the unstressed cable length as the control calculation parameter. The algorithm is programmed into a finite element method software, enabling a precise and well-converged simulation of the cable-stayed bridge construction process. This method has been successfully applied in a kilometer-scale cable-stayed bridge, facilitating the determination of internal forces and girder geometry throughout the construction process. This also streamlines the acquisition of fabrication parameters for individual girder segments. The application results demonstrate that the research presented in this paper provides an efficient and accurate calculation method for determining the fabrication parameters of steel girders in cable-stayed bridges.

Ultimate bearing capacity analysis of self-anchored suspension bridge with steel box girders considering local buckling

The local stability may dominate the design of a self-anchored suspension bridge with steel box girders. Due to geometric imperfections and welding residual stresses rarely considered for its ultimate bearing capacity analysis, the influences of the local buckling on the global structural behavior remain unknown. This paper presents a multi-scale finite element (FE) model for a self-anchored suspension bridge incorporating geometric imperfections and residual stresses in a steel box girder segment simulated by shell elements. Also, the pattern considering the defects in the shell FE model is validated by experiments. An extended parametric study is carried out via multi-scale FE models under various defects. Results illustrate that: ➀ the effects of local buckling on the ultimate bearing capacity of the bridge is small and can be ignored if geometric imperfections and residual stresses are not considered; ➁ the influences of local buckling becomes significant if geometric imperfections and residual stresses are included; and ➂ ultimate bearing capacity decreases with increase of defects, with geometric imperfection being the main factor influencing the ultimate bearing capacity of the bridge. Additionally, the thickness of steel plates has significant influences on the ultimate bearing capacity of the bridge. A comparison between the EN 1993–1-5 and the FE analysis results indicates that the former is conservative. This study provides useful insights for analyzing and designing local buckling from the perspective of steel bridge system.

Work Accident Risk Analysis in Tukad Ayung Bridge Replacement Project

Analysis of the risk of work accidents in the Tukad Ayung Bridge replacement project needs to be carried out by identifying, assessing, and controlling risks using the HIRARC method. This study aims to conduct a work accident risk analysis in the Tukad Ayung Bridge replacement project, precisely in the implementation of concrete girder installation. The data used are qualitative and quantitative data with primary data sources and secondary data. The data collection techniques used are observation, interviews, questionnaires, literature studies, and documentation studies. The data analysis technique used is HIRARC. The results showed that; 1) There are 24 types of work accident risks identified in the concrete girder installation work in the Tukad Ayung bridge replacement project in seven stages of work, namely, the concrete girder preparation stage, girder truss making, erection (segmental girder setting), prestressed steel installation (strand), strand cable stressing work, girder concrete tendon grouting, and diaphragm installation stage, 2) The results of risk analysis on concrete girder installation work on the project The replacement of the Tukad Ayung Bridge, is in the moderate category, which is as many as 12 risks with a percentage of 50%. Furthermore, as many as 11 risks are included in the high category with a percentage of 45.837%. Meanwhile, in the extreme category as much as one risk with a percentage of 4.17%, 3) Risk control efforts that can be carried out from the three levels of risk found, namely moderate, high, and extreme, namely by reducing risk through administrative control, engineering control, and warning system.

Penerapan Manajemen Risiko Kecelakaan Kerja pada Proyek Penggantian Jembatan Tukad Ayung Denpasar, Bali

Management of occupational accident risk involves systematic, planned, structured, and comprehensive efforts to mitigate the factors that contribute to the occurrence of work accidents. This study aims to examine the risk of work accidents in the Tukad Ayung Bridge replacement project, especially at the stage of installing concrete girders. Qualitative and quantitative data from primary and secondary sources were used, collected through observation, interviews, questionnaires, literature review, and documentation analysis. The Hazard Identification, Risk Assessment, and Risk Control (HIRARC) method is used for data analysis. The findings revealed 24 types of work accident risks at seven stages of concrete block installation in the project including the concrete girder preparation stage, girder truss making, erection (setting segmental girder), prestressed steel installation (strand), cabel strand stressing work, concrete girder tendon grouting, and diaphragm installation stage. The results of the risk analysis on the concrete girder installation work on the Tukad Ayung Bridge replacement project, are in the moderate category, which is as many as 12 risks. Furthermore, as many as 11 risks are included in the high category. Meanwhile, in the extreme category as much as 1 risk.

Flexural performance of precast segmental continuous box girders with corrugated steel webs

Due to the existence of joints, the flexural performance of segmental assembled girders is different from that of monolithic cast girders. In order to study the flexural performance of precast segmental assembled box girder with corrugated steel webs, a static failure test on a precast segmental assembled continuous box girder with corrugated steel webs and variable cross-section and a monolithic cast continuous box girder with corrugated steel webs of the same size was carried out. The influence of the existence of joints on the deflection, strain, and prestress increment of precast segmental continuous girder with corrugated steel webs was analyzed. The parameter analysis was further carried out by the finite element method. The results showed that, at the initial loading stage, the joint had little effect on the displacement, and the deflection of the segmental assembled girder changed more rapidly than that of the monolithic cast girder. In the monolithic girder, cracks mainly occurred at the middle-support position of the middle span and pure bending sections. In the segmental beam, cracks were concentrated in the concrete on both sides of the joint. The number of cracks was relatively small and concentrated in the concrete on both sides of the joints of the loading segment and the middle support segment. The trends in the strain growth in the segmental beam and MB01 were consistent, and the values were similar. The strain growth trend of the segmental girder and the monolithic girder was consistent, and the values were similar at the initial loading stage. The external prestressed tendons in the segmental girder had a greater role in the loading process than those in the monolithic girder, and the normal stress in the segmental girder increased more rapidly during the bending process. In the ultimate loading state, the external prestressing force of the segmental girder was 2.01% higher than that of the monolithic girder. The number of segments was inversely proportional to the flexural capacity of the structure. Excessive thickness of the adhesive layer would adversely affect the crack resistance of the structure. This study will contribute to the engineering application of continuous composite box girders with corrugated steel webs.

Experimental and Numerical Analysis of a Temporary Bridge Connector Consisting of an Upper Bearing Block–Lower Pin Configuration

In this study, the structural details of a hinge connection for steel girder segments were developed to improve the process of rapid and easy construction. In the connector developed in this study (referred to as the “speedBridge” hereafter), the compression load exerted on the upper flange is resisted by two bearing blocks in contact with each other, and the tensile force on the bottom flange is resisted by the hinge structure installed at the lower part of the steel girder. The structural behavior of the developed connection was investigated experimentally. It was shown that the developed connection details could develop an excellent connection plastic rotation of 5% rad without fracture. The test specimen developed initial stiffness in accordance with elementary beam theory for a supported beam. The maximum load reached 110% of the plastic moment of the beam. Finite element analysis was conducted to comprehend the load transfer path, and the results demonstrated that the hinge connection exhibited sufficient stiffness and strength, exceeding the bending capacity of the beam under tension without any signs of the failure modes considered in the design procedure.

Experimental investigation of bearing capacity of 3D printed concrete segmental girder

3D concrete printing (3DCP) technology represents a new approach to producing contemporary concrete structures. The application of sophisticated equipment such as a 3D printer has brought numerous advantages, which were noted through significant practical application. Currently, 3DCP technology is being developed in two main directions: on-site production of entire structures and prefabricated construction. However, 3DCP technology has not yet reached its full potential in prefabrication as the connections between individual segments and their capacities under horizontal and vertical loads, have not yet been extensively investigated. This paper focuses on the experimental testing of the bearing capacity of a beam constructed by connecting individual segments of 3D printed concrete. The segments are connected using post-tensioning steel bars. The experimental program included testing a single segment as well as a segmental girder in a 3-point test. In the case of the individual segment, failure occurred due to the loss of tensile capacity of the concrete. For the segmental beam, failure occurred when the shear capacity was reached. Shear fracture was accompanied by diagonal cracks extending from the point of force application towards the beam supports.

Experimental Study on Failure Mode of Precast Assembled Segmental Beams under Impact Loading

Precast segmental girder bridges are threatened by impact loads during service, but there is currently little research on the impact behavior of such bridges. This study investigated the dynamic responses and failure modes of precast assembled segmental beams experimentally and numerically. 10 beam specimens were designed for static and impact tests, respectively. Numerical simulations were conducted in LS-DYNA and verified by comparing them with the test results. Failure mechanisms were analyzed by verified models. The results show that the local shear failure mechanism is prominent under impact loading. Two typical failure modes were obtained: oblique section failure and joint section direct shear failure, which are related to the relative positions of joint and impact point. Confining stress can effectively improve the static bearing capacity and impact resistance, but has little effect on the early response and final failure mode. The main failure cracks occur near the joint bottom in the initial stage of impact, when the impact force is resisted by the inertia force, resulting in a characteristic “N” shape in shear force distribution. Shear failure of the joints dominates the beam failure mode. A dynamic shear span ratio can evaluate the early force characteristics of the joint section.

Numerical and experimental study of a segmentally prefabricated orthotropic steel–ultra-high-performance concrete composite deck for long-span cable-stayed bridges

Utilizing the high strengths, toughness, and durability of ultra-high-performance concrete (UHPC), a segmentally prefabricated orthotropic steel–UHPC composite deck (POSUCD) system has been developed for long-span cable-stayed bridges. The deck system combines an orthotropic steel deck (OSD) with a reinforced UHPC layer using notched perfobond strips (NPBLs). The UHPC layer is prefabricated onto the OSD of the girder segment in the factory to form the POSUCD. After the precast UHPC layer is cured, the girder segments are transported to the bridge site and assembled. The precast UHPC layers are then connected via transverse wet joints before tensioning stay cables. Against the background of the Danjiangkou Reservoir Bridge with a main span of 760 m, finite element (FE) analysis was conducted to examine the stress state and flexural tests were carried out on local full-scale models to verify the feasibility of POSUCD. The results show that the prefabricated UHPC layer reduces the maximum static compressive stress of the steel deck in the girder system by 21%, and the stress ranges at fatigue-prone details of the steel deck are decreased by 28%–90% compared to traditional OSDs with asphalt overlay. Since the prefabricated UHPC layer helps withstand dead axial load in the main girder, the high compressive strengths of UHPC can be utilized more effectively than in deck systems with UHPC only used as a cast-in-situ overlay to resist vehicular wheel loads. The transverse wet joint interfaces were identified as the weakest aspect of the POSUCD, whether under tension or compression; however, their nominal flexural strengths along the longitudinal direction meet the required design standards. The shear resistance of NPBLs was also well confirmed by the minimal interfacial slip on the specimen when it reached the ultimate capacity under positive bending moment.

Shear stress at joint of prefabricated-composite box girders with corrugated steel webs

This paper studies the shear stress at the connection joints of a segmental prefabricated-composite box girder with corrugated steel webs. As the shear bearing capacity of the top and bottom concrete flanges of the segmental girder is weaker than that of an integral girder, this study focuses on the shear behavior at the combined joints of bridge segments under vehicle loads. The effects of concrete shear connector, concrete friction, the adhesive layer and steel web on the shear bearing capacity are considered. Laboratory tests were carried out for the segmental girder and an integral box girder as a reference. The structural behavior of the test girders' joint surfaces was also simulated through finite element analysis. Results show the shear bearing capacity formula for concrete box girders from the AASHTO Standard can be factored by a reduction coefficient of 0.9 to achieve a more accurate calculation. It shows that the modified formula can accurately reflect the shear stress variation trend of composite joints, and the percentage differences between the calculated values using the modified formula and those from experimental tests and simulations are both within 5%.

COMPARATIVE STUDY ON THE GIRDER ERECTION SCHEME FOR THE CHIBI YANGTZE RIVER HIGHWAY BRIDGE

The construction process of composite cable-stayed bridges varies, and it closely affects the finished bridge. This study takes the Chibi Yangtze River Highway Bridge, which is the world's largest-span composite cable-stayed bridge, as an example in determining the optimal scheme of girder erection during the construction of the composite cable-stayed bridge. Six girder construction schemes were proposed for comparison and analysis. On the basis of satisfying the objective principles of the finished bridge, the stress safety principle, and the economic principle, qualitative and quantitative methods were used to analyze the girder erection schemes. The refined model of the composite girder segment was established by the finite element software ABAQUS to examine the local stress of the bridge. Subsequently, the optimal scheme of girder erection was determined. Then, the key calculation results of the optimal scheme of girder erection during the construction stages and for the finished bridge were given, which proved the feasibility, safety, economy, and controllability of the proposed optimal scheme. Results show that the measured data of the girder line shapes and the cable forces of the finished bridge agree well with the theoretical values. This agreement verifies the correctness of the determination and demonstration of the proposed optimal scheme. This study provides a certain reference for the determination of the girder erection scheme of composite cable-stayed bridges. Keywords: Composite girder; cable-stayed bridge; steel girder erection; single segment one cycle; two segments one cycle; construction process;

Explosion resistance performance of reinforced concrete box girder coated with polyurea: Model test and numerical simulation

To study the anti-explosion protection effect of polyurea coating on reinforced concrete box girder, two segmental girder specimens were made at a scale of 1:3, numbered as G (without polyurea coating) and PCG (with polyurea coating). The failure characteristics and dynamic responses of the specimens were compared through conducting explosion tests. The reliability of the numerical simulation using LS-DYNA software was verified by the test results. The effects of different scaled distances, reinforcement ratios, concrete strengths, coating thicknesses and ranges of polyurea were studied. The results show that the polyurea coating can effectively enhance the anti-explosion performance of the girder. The top plate of middle chamber in specimen G forms an elliptical penetrating hole, while that in specimen PCG only shows a very slight local dent. The peak vertical displacement and residual displacement of PCG decrease by 74.8% and 73.7%, respectively, compared with those of specimen G. For the TNT explosion with small equivalent, the polyurea coating has a more significant protective effect on reducing the size of fracture. With the increase of TNT equivalent, the protective effect of polyurea on reducing girder displacement becomes more significant. The optimal reinforcement ratio, concrete strength, thickness and range of polyurea coating were also drawn.

Flutter performance of a double-main-span suspension bridge during erection with temporary constraints on girders

An increasing number of double-main-span suspension bridges with three towers are now constructed. For this bridge type, close modes exhibits similar characteristics due to the participation of two main and side spans, which is more prominent during girder erection as different spans are disconnected. It is important but hard to accurately determine the modal combination for flutter analyses. In this paper, full-order modal flutter analyses were performed to study the flutter performance of a double-main-span suspension bridge during erection. The dominating modal branches for the anti-symmetrical and symmetrical flutter instability were determined, respectively. After that, temporary pier constraints on the side spans and temporary connections between girder segments were set, respectively, to study the flutter suppression. The results show that the anti-symmetrical flutter instability of the bridge during erection is prior to the symmetrical one except for the first two stages. Reinforcing the connections between girder segments in the lateral direction could significantly improve the anti-symmetrical flutter stability. Meanwhile, the symmetrical flutter instability of the bridge during erection is more complicated as it is associated with the girder torsion, cable swing, and girder lateral bending. The set of temporary pier constraints or proper temporary connections is favorable.

Performance of steel cable-stayed bridges in ship fires, part I: Numerical method and baseline fire scenario study

Over the past decade, the previous hysteretic recognition of the fire threat to bridges has provoked significant progress in understanding the fire performance of bridges. However, despite the growing maritime shipment of combustibles, scarce studies have contributed to evaluating the safety of steel cable-stayed bridges subjected to under-girder ship fires. Limited existing knowledge is still based upon the less precise temperature curve method and flame geometry modeling. This study developed an advanced numerical method to more accurately evaluate the response of steel cable-stayed bridges subjected to ship fires. First, the computational fluid dynamics (CFD) approach was used to reproduce realistic fire conditions. An efficient thermal boundary, adiabatic surface temperature, was then transferred to the thermal finite element model of affected girder segments for calculating the temperature propagation. Lastly, this paper used the multiscale structural finite element method to incorporate the local performance variation of exposed girders into the response of the entire bridge. The proposed method was validated by predicting a thermomechanical response of the steel beam exposed to realistic underneath fires, agreeing well with the data from two large-scale structural fire experiments by NIST. Based on the method, the response of a typical steel cable-stayed bridge subjected to ship fires was simulated. Results show that fires can introduce local damage to the girder segments above the fire and alter the internal force distribution of the entire bridge. The bending moment of the girder sections over the fire significantly increases, and the flexural characteristic of pylons is also altered. Both thermal convection and radiation contribute to the temperature increment, and the latter dominates at the locations above fires. Adopting temperature curves can overestimate or underestimate the fire impact, introducing uncertainties to the safety of steel cable-stayed bridges in ship fires and can cause unrealistic stress concentration on the border of heated and unheated domains of exposed floors. The developed advanced method is more competent in capturing the inhomogeneous temperature and stress distribution.

Seismic Vulnerability Analysis of Long-Span Prestressed Concrete Composite Box Girder Bridge with Corrugated Steel Webs under Construction

In order to address the difficulty in determining the seismic damage probability of continuous girder bridges under construction, the seismic vulnerability analysis method of the construction state is proposed in this study. Firstly, taking a long-span prestressed concrete composite box girder bridge with corrugated steel webs (OSW) as an example, the finite element models (FEMs) of dynamic calculation in different phases of cantilever construction are simulated by OpenSEES. Secondly, by selecting reasonable seismic waves and seismic intensity measures, the non-linear time-history analysis is carried out, followed by the demand parameters and damage indexes suitable for the construction state proposed. Finally, the probabilistic seismic demand model (PSDA) of the continuous box girder bridge during the construction stage is constructed by using the “cloud method”, and the seismic vulnerability curves of the piers and temporary bearings are established to evaluate the seismic performance during the construction stage. The results indicate that the damage probability of piers and temporary bearings increases with the progress of construction. The initial formation of the cantilever structure and the sudden change in the size of the construction segmental girder correspond to a high probability of damage, and seismic protection measures should be strengthened during this construction state. Moreover, significantly higher damage probability of the components under construction compared to the completed bridge after it is built.

Damage behavior of extra-wide reinforced concrete box girder with multiple chambers under repeated explosive loads: Testing and numerical simulation

Explosive tests of scaled girder specimens and numerical simulations of prototype girder segments were implemented to study the dynamic response and failure characteristics of extra-wide reinforced concrete box girders subjected to repeated explosions. First, a segmental girder specimen was manufactured at a reduced scale of 1:3 based on the prototype girder of a real bridge. The damage behavior of the specimen was tested by detonating two 3-kg TNT (trinitrotoluene) grains in sequence at a height of 0.40 m above the center of the middle chamber. Second, LS-DYNA software was used to simulate the explosive response of the specimen. The reliability of the numerical simulation method was verified by comparing its results with test data. Finally, the effects of different TNT equivalents, detonation positions, and repeated explosion modes on the anti-explosion performance of the prototype girder segment are simulated. The results showed that the holes in the top plate of the middle chamber of the girder specimen were 41.50 cm × 45.50 cm and 56.80 cm × 63.50 cm along the longitudinal and transverse directions, respectively, under the two explosions. The concrete at the bottom of the top plate peeled off over a wide area, and cracks appeared in the bottom plate close to the supports. In comparing the simulated damage behavior of different girder segment types along the transverse direction, the dynamic response of the T-beam section segment was found to be greater than that of the box section segment under the same explosive charge. The maximum response was located at the road centerline. Moreover, the degree of damage to the girder was more severe under repeated explosions with a certain amount of charge compared with that under a single explosion with twice the amount of charge. The degree of damage to the web, bottom plate, and crossbeam caused by the explosions in sequence from outside to inside the box with two 200-kg TNT grains was more severe than that caused by a single explosion of 400-kg TNT grains. Simultaneous detonations at multiple positions severely degrade the bridge traffic capacity.

Experimental investigation of a precast segmental Twin‐Deck box girder bridge simultaneously erected with double bridge erection gantries

AbstractPrecast segmental construction can shorten the construction time of the bridge and reduce the impacts on traffic and environment. Thus, this approach has been widely used in many countries. The relevant literature suggests that in the existing segmental precast bridges, nearly all of the centerlines of the girders are aligned with the centerline of the bridge piers. This paper introduces a wide urban viaduct comprising twin separate box girder cells using segmental prefabrication. To save space under the bridge, the bridge has only one row of piers and long cantilever crossbeams are set at the top of each pier. Additionally, the centerline of the girder and the centerline of the pier do not overlap. To prevent eccentric loading and improve the construction speed, two bridge erection gantries are used for synchronous construction. This study is a pioneering attempt at bridge construction with a precast segmental twin‐deck box girder bridge simultaneously erected with double gantries. To investigate the stress state of the whole system (crossbeam, gantries, and box girder segments) during construction and demonstrate the feasibility of the construction method, a real bridge was used. The test results provide a reference for the design and construction of similar projects.

Shear lag effect of composite cable-stayed bridges under dead and live loads

The modern composite cable-stayed bridge always has a wider deck, and the slab has an obvious shear lag effect. At the operation stage, internal forces distribution of the composite girder under live loads differs from that under dead loads only. It is essential to investigate the shear lag of the main beam under dead and live loads. Then, in-situ tests under truck loads were carried out on Xia Zhang Bridge. Considering the superposition of axial forces, a simplified method is proposed to evaluate the effective width. The finite element models (FEMs) of the full bridge using solid shell elements under dead and live loads were established. The longitudinal distribution of the effective widths for concrete slabs under different loading positions and loading forms was obtained. Furthermore, the full-scale variable parameter analysis considering the effects of span lengths and deck widths was conducted by FEMs. The numerical results show that the composite girder segments at the location of the bridge tower and the loading position need to be concerned for shear lag analysis. A generalised verification for a cable-stayed bridge was made, and compared results show that simplified methods can calculate the normal stresses in slabs more accurately than Eurocode 4.