Bridge Load Research Articles

Analysis and Design of Superstructure of Bridge Built Through Engineering College Premises

Abstract: The earlier publication from the authors focused on “The bridge through the college” which highlights how contracts and agreements signed many decades ago have to still be respected and fulfilled. A public highway planned to originally be laid on top of a filled-out irrigation canal passing through the campus of a college that commenced in 1977 was later replaced with an elevated bridge that was completed in 2023 and is now open to the public. The first part of the two-stage manuscript elaborated on the conception of the bridge, the general layout, geometry, and construction of this reinforced concrete girder bridge. The challenges associated in the process of engineering and construction as well as the opportunities missed were discussed. The second part of this study details the analysis process of the girders, the static and dynamic bridge loads considered, the code specifications and guidelines followed. The results of the analyses present the strength and service level member forces the bridge girders and slab are subjected to, and the design governing load combination envelopes. The study presents the superstructure girder designs, slab designs and the design methodology followed overall.

Deformation Responses of a Geosynthetic Reinforced Soil-Integrated Bridge System Under Static Loading and Sensitivity Analysis of Influential Factors Based on the Improved Grey Relational Method

A numerical parametric study is conducted to evaluate the effects of various parameters on the deformation responses of a geosynthetic reinforced soil-integrated bridge system (GRS-IBS) under static load. The investigated parameters include the abutment height, reinforcement spacing, reinforcement length, reinforcement stiffness, bridge load, and backfill internal friction angle. The improved grey relational method is used to investigate the sensitivity of influential factors on the deformation responses of the GRS-IBS. The simulation results indicate that the abutment height, reinforcement spacing, and bridge load have a significant impact on the performance of the GRS-IBS with respect to lateral displacement and settlement, while the effects of reinforcement length, reinforcement stiffness, and backfill internal friction angle on the deformation behavior of the abutment are negligible. Differential settlements between the girder and approach are minimal under all conditions. The potential failure envelope of the GRS-IBS exhibits a “L” shaped configuration where the potential failure surface starts beneath the inner edge of the strip footing, extending vertically downward to half of the wall height and further bifurcating toward the strip footing and the toe of the wall. The results of the improved grey relational analysis show that reinforcement spacing is the most sensitive to the lateral displacement of the GRS-IBS. The abutment height and bridge load are more sensitive to abutment deformation than other influential factors. These three parameters are crucial to the deformation behavior and should be given primary consideration when designing a GRS-IBS.

Application Research of BIM Technology in Bridge Monitoring

According to the development situation of BIM technology and the application of bridge monitoring methods, this article proposes the design and application of bridge monitoring platform based on BIM technology, integrating the collection, data analysis, data transmission, safety assessment and prediction of basic bridge data. Then, according to the bridge load, the overall structure and the local data, it conducts the overall prediction and evaluation of bridge safety status, which can provide the method reference for the later maintenance and operation of the bridge.

Investigations on the fatigue loading of thin-walled and resource-efficient UHPFRC segmental bridges

Many reinforced concrete and prestressed concrete bridges are defective or can no longer withstand the increased traffic loads for a sufficiently long time. In the long term, they will have to be replaced by new structures. In previous reinforced concrete and prestressed concrete bridges, fatigue loading (e.g. traffic, wind) is rarely a problem with regard to the concrete, especially since the cyclic traffic loads are relatively low compared to the static dead loads due to a solid construction method. However, for reasons of sustainability and compliance with climate targets, future structures and bridges should be built in a resource-efficient and materials-compatible manner, while at the same time fast and durable. A target-oriented approach to this is segmental bridge construction with keyed dry joints made of ultra-high-performance fiber-reinforced concrete (UHPFRC). In these bridge structures the fatigue loads could become more relevant due to the slenderness of the thin-walled UHPFRC bridges superstructure and fatigue problems could occur. In order to investigate this in more detail, FE investigations on segmental box girder bridges under variation of the concrete strength (NSC, HSC and UHPFRC) were carried out, while optimising the cross-section dimensions. It was shown that due to the performance of UHPFRC and the associated cross-section optimisation, an exponential increase in the ratio of cyclic live loads to static dead loads and thus an exponential increase in fatigue loading occurs at thin-walled and resource-efficient UHPFRC segmental bridges compared to NSC and HSC bridges and that this can become relevant for the design of such bridges.

COMPARISON ANALYSIS OF EXISTING BRIDGE DESIGN BASED ON BMS 1992 AND SNI 1725-2016

Bridges are an important element of infrastructure facilities to support the economy and sustainable development. The design of bridge structures often develops over time, as well as the development of criteria as well as applied sciences that are developed and sustainable with the rules that have been listed. The truss type bridge structure is one type of bridge that is often used in Indonesia. Based on Binamarga standards, the bridge is planned with a design life of 50 years, the 50 years of this course will be followed by an orderly and good maintenance. The 50-year period is used as a standard taking into account the existence of material innovations used to the loads that will affect the bridge. Software development certainly supports the design at the beginning of the bridge project construction, in this case the bridge project uses SAP90 and STAAD-Pro as software to support this bridge design. Until now, of course, the software used is very diverse, one of which is ETABS, which is used in the design of a construction project. The existence of a thorough structural analysis with load analysis to connection analysis is the stage in the analysis for the condition of the bridge to the load with several reduction factors to load values that have different requirements. With a thorough design with 2D analysis along with ETABS software, based on the latest SNI 1725-2016 rules regarding the loading of bridges, a higher steel weight ratio is obtained when compared to the initial design, but this can be overcome by monitoring maintenance to the extent that In particular, some intensive handling is required for the safety and function of the bridge.

Theory and Empirical Analysis of Bridge Load Limitation Under the Action of Typical Heavy-Duty Vehicles

Abstract With the continuous growth of transportation demands, in-service highway bridges face greater challenges in their long-term operational lifespans, and bridge collapse accidents caused by vehicle overloading occur from time to time. Additionally, under the influence of loads and environmental factors, various wear patterns inevitably lead to degraded reinforced concrete bridges. In view of this problem, it is reasonable and feasible to limit the vehicle loads passing over highway bridges, and the key basis for limitation is determining the load limit value of a bridge. To determine a reasonable load limit value of a bridge, this paper has carried out the following research: Based on a classification of vehicle types, this paper explores the load parameters of several heavy-duty vehicles with large traffic volumes through traffic flow information and summarizes the load spectra of typical heavy-duty vehicles. On the basis of the theory of structural reliability, a method for determining the limit load of bridges is proposed. Given a structural target reliability index, the theoretical load limit value of a bridge can be calculated. To ensure the rationality of the theory of bridge load limit value, by relying on the engineering example, the theoretical load limit value is calculated. By comparing actual bridge load test data with the finite element model results, the rationality of the bridge load limiting theory is verified. Finally, the paper notes that it is safer and more reliable to define the load limit value according to the bending stress state for bridges.

Stress Analysis of Pin Connections in Steel Box Girder with the Unibridge System using Finite Element Model

This study analyzes the Unibridge system, a modular steel box girder employing two pins for longitudinal connections, thereby expediting construction compared to traditional girders. A finite element model was developed to analyze the stress on these pins in a single-box girder with five segments and a reinforced concrete floor slab. Various loads were applied following the Indonesian bridge loading standard, SNI 1725:2016. The model considers operational load analysis and assumes full composite behaviour between the top flanges of the girder and the concrete floor slab. The results indicate that the Von-Mises stress on the pins reaches a maximum of 490.95 MPa under combined service loads, consistently remaining below the specified material yield stress limit of 1200 MPa. Consequently, the Demand Capacity Ratio (DCR) is 0.41. As a result, the Unibridge girder connection pins do not experience plastic deformation under the applied loads.

Evaluation of bridge load capacity using proof-load tests

A proof-load test is often necessary to accurately measure the field behavior of a bridge structure. A new segmental steel bridge has been constructed over the Tisza River in Hungary. The bridge comprises of two independent steel box girders assembled by a welding system. Engineers performed proof load tests before opening the structure to evaluate its load-carrying capacity and deck deflection. This paper presents several aspects of the load testing and evaluation of the bridge structure under static and dynamic loads using a rating factor (RF) approach compared to a baseline finite element model. The load test results helped to calibrate the model and verify the method. The study reveals that the tested bridge has an elastic behavior, a high capacity, and adequate dynamic performance.

RECENT ADVANCES IN THE FIELD OF BRIDGE LOAD TESTING

Load testing of bridges is commonly used to verify the performance of a bridge prior to opening as well as for the assessment of existing bridges. This paper reports on recent advances in the field of bridge load testing, based on experimental work carried out in Europe as well as international collaboration efforts. The experimental, numerical and analytical work that has been carried out in these past years is summarized. The main findings are: 1) modern instrumentation techniques (such as acoustic emission measurements and digital image correlation) can be combined with traditional measurements to gain more in-depth insights during and after the test; 2) for load testing to be fully compliant with current codes, a probabilistic substantiation of the methodology is needed; and 3) international collaboration is key in order to successfully update current codes and guidelines and develop recommendations and sets of best practices. The recent advances in North America and Europe have also resulted in improvements to the practice of bridge load testing in Latin America (in particular in Costa Rica and Colombia). To conclude, load testing is an important tool for engineers faced with the task of assessing existing bridges. The aforementioned efforts will result in improved recommendations for the assessment of concrete bridges by load testing to be included in codes and guidelines in Ecuador and other countries in Latin America.

Ultimate Load-Bearing Capacity and Sustainable Performance of Pile Foundations of Yanji Suspension Bridge in Fault Zone Based on Refined Geological Model

Pile foundation is the most important foundation type of long-span bridges, of which the ultimate load-bearing capacity affects the safety and sustainable performance of bridges. When constructing large-span bridges, the bridge site may be close to the adjacent fault zones, which seriously affects the safety and long-term performance of pile foundations, causing the failure and unsustainability of long-span bridges in their life-cycle service life. At present, there are no engineering design rules or methods for assessing the load-bearing capacity of the pile foundation near the fault zones. To study the influence of the fault zone on the loading-bearing capacity and sustainable performance of pile foundations, triaxial compression tests were carried out on the mylonite at the Yanji suspension bridge site near the Xiangfan–Guangji fault zone in Hubei Province. The mechanical properties of mylonite were reflected by the Mohr–Coulomb yield criterion, and a topographic and geological modeling method based on the multi-platform was established. Then, the ABAQUS finite element software was used to study the deformation, stress, failure modes, and sustainable performance of the pile foundation under different bridge load levels, analyze the safety of the pile foundation in the fracture zone, and summarize the ultimate bearing characteristics of the pile foundation. The results show that the whole pile and surrounding rock are basically elastic under the pressure of the designed load, the plastic zone of the pile foundation is mainly concentrated at the pile bottom, and the shear stress concentration zone of the pile is mainly manifested in the joint of the cap and pile and the interface between soft and hard rock. When the load is increased to 4 times the designed load, the stress concentration area of the pile body gradually shifts upward from the pile bottom, and the surrounding rock at the bottom forms an “X-shaped” shear failure zone. After 100 years of operation, the maximum compressive stress of piles reaches 28.6 MPa, which is 120% higher than that at the beginning of the bridge construction, indicating that the sustainable performance of the piles can withstand the effect of the fault zone over the designed service years.

A Case Study for Stability Analysis of a Toppling Bank Slope with Fault Fracture Zones Developed under the Action of Bridge Loads and Reservoir Water

The mountainous areas of Southwest China have the characteristics of valley deep-cutting, a large topographic gradient, complex geological structures, etc. With the development of infrastructure construction in the area, the construction of bridges across valleys has gradually increased, and the phenomenon of slope failure occurs more and more frequently. As the weak interlayer, the fault fracture zones have a significant influence on the geological structure and stability of slopes, while the complexity of the mechanism of the deformation and failure of slopes increases with the combination of the development of the fracture zones and toppling deformation. This paper took the toppling bank slope of bridge foundations developed with fault fracture zones in Lancang River as the research object. Through an on-site field survey and geological survey technologies, it identified the distribution range of the fracture zones on the bank slope and determined the characteristics of the rock mass in the fracture zones. A stability evaluation model for the bank slope of the bridge foundations was established using the limit equilibrium method and discrete element method. Based on the two-dimensional limit equilibrium analysis, the potential failure modes of the bank slope were explored, and the stability of the bank slope under bridge loads was calculated. Through the three-dimensional geological model of the bank slope, including the fracture zones and toppling bodies, the three-dimensional discrete element numerical simulation method was adopted to simulate and calculate the deformation and failure process of the bank slope under different bridge loads and working conditions. According to the calculation results, the influence of bridge loads and reservoir water on the stability of the bank slope was analyzed from the perspectives of displacement, plastic zone, stability coefficient, and other factors. The formation process of the plastic zone and the development of the sliding surface were revealed, the incentive mechanism of bridge loads and reservoir water on the deformation and failure of the bank slope was analyzed, and the influence of fault fracture zones on the stability of the bank slope and the development of toppling deformation was determined. The results indicate that the fault fracture zones are important geological structures that affect the deformation and failure of the bank slope as a weak interlayer. Under the influence of bridge loads and reservoir water, the stability of the bank slope is affected by the quality of the rock mass and the development of the fault fracture zones, resulting in the unmet need for safety requirements and maybe leading to instability. Based on the calculation results of the stability evaluation prediction model for the bridge foundation bank slope and the engineering geological conditions, the bridge scheme has been selected.

The Influence of the Variation in Arch Height of the Main Tayan Bridge on the Member Forces

The height of the bridge arch significantly impacts the strength and structural efficiency. Research on the height of the Tayan Bridge arch was conducted to determine the values and behaviour of member forces, structural weight, and deflection and to design the optimal arch height geometry. This research involved five variations of the arch height. The bridge structure was modelled using AutoCAD software. Relevant bridge loading data based on the SNI 1725-2016 standard was inputted into AutoCAD for structural design, and then the structure was modelled and analysed using SAP2000. The analysis results provided information on the bridge weight, deflection, and member forces. The analysis results were then compared with the bridge arch height, and this comparison was presented in the form of graphs. From the analysis results, it can be concluded that the bridge arch height has a positive linear relationship with the bridge weight. Tensile and compressive forces exhibit opposite behaviour. Increasing the arch height with constant value results in weight, deflection, and member force variations. Constantly expanding the arch height also does not lead to an increase in the stiffness of the bridge. Structurally, the optimal arch height is 42.134 meters.

Characterizing Bridge Thermal Response for Bridge Load Rating and Condition Assessment: A Parametric Study

Temperature is the main driver of bridge response. It is continuously applied and may have complex distributions across the bridge. Daily temperature loads force bridges to undergo deformations that are larger than or equal to peak-to-peak traffic loads. Bridge thermal response must therefore be accounted for when performing load rating and condition assessment. This study assesses the importance of characterizing bridge thermal response and separating it from traffic-induced response. Numerical replicas (i.e., fine element models) of a steel girder bridge are generated to validate the proposed methodology. Firstly, a variety of temperature distribution scenarios, such as those resulting from extreme weather conditions due to climate change, are modelled. Then, nominal traffic load scenarios are simulated, and bridge response is characterized. Finally, damage is modelled as a reduction in material stiffness due to corrosion. Bridge response to applied traffic load is different before and after the introduction of damage; however, it can only be correctly quantified when the bridge thermal response is accurately accounted for. The study emphasizes the importance of accounting for distributed temperature loads and characterizing bridge thermal response, which are important factors to consider both in bridge design and condition assessment.

Design of UHPC prestressed girders for shear

AbstractBreakthrough technology of ultra‐high‐performance concrete (UHPC) introduced in the 1990s exhibits several exceptional mechanical properties that are advantageous in elements of bridge applications. Extensive research has aimed to industrialize UHPC and develop design models. This paper investigates several design models for shear, including a unified approach with that of conventional concrete based on the modified compression field theory (MCFT). An experimental database of UHPC prestressed concrete girders subjected to shear failure is compiled to evaluate model accuracy and a reliability study is conducted to establish appropriate safety factors. The analysis demonstrates that the proposed MCFT‐based model aligns well with experimental results, exhibiting a suitable level of conservatism for design. A reliability assessment of a typical prestressed girder designed according to Canadian Standards Association building and bridge loadings is performed, resulting in a structural reliability evaluation against a target reliability index. The study recommends specific strength reduction and safety factors for design approaches using UHPC.

A hybrid virtual–real traffic simulation approach to reproducing the spatiotemporal distribution of bridge loads

AbstractCurrent traffic simulation approaches analyze vehicle loads and load effects from a statistical perspective; however, they fail to reproduce the spatiotemporal distribution of bridge loads and resultant load effects at every moment, hindering real‐time bridge health management. This paper proposes a two‐step hybrid virtual–real traffic simulation (HvrTS) approach to reproduce the spatiotemporal distribution of bridge loads. Vehicle load sequences are first identified using computer vision based on traffic video from two surveillance cameras installed along the bridge. Next, traffic microsimulation is optimized with the identified vehicle load sequences from the two cameras serving as the known input and validated output. Using a cable‐stayed bridge under free‐flowing traffic, the HvrTS approach achieved a weighted mean square matching error of ≤0.3 m for the vehicle longitudinal location and a matching error of ≤7% for the vehicle lane position, whereas with congested traffic, the matching errors were much higher due to the inherent complexities and challenges associated with reproducing vehicle behavior in heavily congested situations. The traffic load effects calculated via HvrTS presented excellent spatiotemporal matching with those measured by a structural health monitoring system, especially in free‐flow traffic conditions. Applications on a continuous rigid frame girder bridge further validate these findings. Hence, the proposed HvrTS approach can overcome the challenge of spatiotemporal matching between vehicle loads and load effects in field monitoring.

Fatigue vulnerability assessment of a steel arch bridge using the probabilistic weibull model and considering its remaining service life under localized corrosion effects

This study attempts to obtain the approximate fatigue vulnerability of a steel arch bridge from the Colombian national road network. It establishes the interaction between the demand and the available capacity through the Weibull probability equation, and an AASHTO remaining-time equation indicated in (FHWA, 2015). However, the available capacity in terms of the S-N curve obtained from available international references was modified to account for the effects of corrosion present in elements and/or joints in the bridge. The load demand was modeled as the controlled action of the fatigue truck reported in AASHTO, which was systematically located on a structural model represented by Shell and Frame type finite elements, which represented the information available in drawings (in the current Colombian bridge management system), and the one obtained from structural survey activities. The structural model was further calibrated by a parametric study on the modulus of elasticity of steel, which included the minimization of the error difference in the vertical deflections of a bridge load test, keeping the magnitude within the expected ranges established in a protocol. Such reports of actual deflections were achieved using distance meters at important points of the bridge. This model allowed for estimating the magnitude of stresses in the structural elements of the bridge, especially in an area of interest for the study where chemical and physical elements of structural deficiency were determined. The results show an inverse relationship between the probability of failure and remaining service life. The effect of corrosion on the remaining capacity and the probability of failure of the structural elements is clear.

The Risk of Failure Assessment in Bina Marga Standard Designed Prestressed Concrete Girder Bridges under B-WIM Load Measurement

The use of precast prestressed concrete girder bridges in Indonesia has been increasing rapidly due to their high quality, reliability, and faster construction on site. The girder components are typically designed for a specific bridge span and can be prefabricated. The Directorate General of Highways of the Ministry of PUPR (Bina Marga) has released a standard design for prestressed concrete girder bridges with a typical span of up to 40 m. This design is based on the bridge loading standard SNI 1725 2016, which determines the live traffic load through consensus due to limited data on actual traffic load measurement results. However, the Ministry of PUPR has been implementing actual traffic load measurements using weigh-in-motion (WIM) technology to directly measure the load of passing vehicles. In this study, a risk assessment of the failure risk of a standard Bina Marga bridge with a 40-m span prestressed concrete girder type was conducted based on B-WIM load measurements. The results of this assessment indicate that the standard Bina Marga bridge has a failure risk of 1.48 x 10-4, which is smaller than the acceptable risk of failure according to the AASHTO LRFD Bridge Design Specification as referenced in SNI 1725 2016.

Towards reliability of load-bearing beams of bridges (Tomsk)

One of the criteria for assessing the reliability of load-bearing elements of bridges, are peak values of the temporary mobile load significantly exceeding the standard level of loading. Peak loads are interpreted as a continuous random process in the form of a random pulse sequence manifested after a random period of time and having a random duration.Purpose: The aim of the paper is to show changes in temporary mobile load over time in the form of a simple Poissonian flow, where the bridge load is independent, and repeatability and duration of the random load are independent random variables.Research findings: Three cases are considered to determine sufficiently low probability of destructive temporary mobile loads during the given normative service life of bridges. Based on the failure types, the average failure-free operation of the beam is determined as well as the operating time for a possible failure with a prolonged or specific excess load.

The Effects of River Torrents and Debris on Historic Masonry Vaulted Arch Bridges

The carrying capacity for vertical loads of well-maintained masonry arch bridges is reasonably high. This might not be the case for horizontal loads, the effects of which have not been the subject of extensive research aside from seismic occurrences. Arch bridges crossing rivers are subjected to sudden horizontal loads, due to river torrents, carrying debris from higher grounds. The magnitude of these horizontal loads is similar to those of coastal waves and debris; however, their effect on these structures has yet to be explored in detail. The narrow and high Devil’s Bridge across the Arda River (BG) and the wide, low Candia Viaduct across the Sesia River (I) were chosen as examples. Both are strongly exposed to fast-washing flow in the river during spring. FE simulations show that the impact of the rapidly rising river water influences the general stability, while the effect of debris mainly causes local damage. The results exhibit that tall, slender masonry arch structures fail due to the brittle fracture of the material, followed by the shear failure of a pier body. In contrast, lower and wider viaducts fail due to exaggerated tensile cracking in the upstream parts of a pier and the associated increasing pressure at its downstream parts.

Study of Rail Structure Interaction on Double-Decker integrated bridge with Metro and Highway Structure

In the metro rail system, Long Welded Rails (LWR) have been used for less maintenance, smooth & safe ride at higher speeds. The arrangement of connecting rail and deck system causes an interaction effect in force transfer. The study of this effect in the structure is Rail Structure Interaction (RSI) analysis. In this study, the behavior of double-decker integrated structure, rail stresses and relative deformation are studied due to the bending behavior of the deck, bearing articulation & support stiffness with the proposed geometrical arrangement of the bridge and applicable loading as per standards. The effect of RSI analysis and limitations of additional stresses are referred with the guidance of UIC standards & RDSO guidelines. The double-decker elevated viaduct structure is proposed with a first level highway deck carrying highway loading and second level metro system carrying metro loading. In highway bridge deck, the decks are proposed with four span continuous to avoid discomfort due to more number of expansion joints and thereby provide smooth riding for passengers. The effect of RSI is studied in this paper by considering the above complexity of two-level superstructure with a different type of superstructure at the metro level due to the track requirement like U girder deck system at each track, I girder deck system as a single deck for both the tracks at the cross over / pocket track locations and I girder deck system at highway level with deck continuity. A finite element analysis is performed using the analytical tool MIDAS CIVIL software to study the interaction mechanism for this double-decker bridge structure. For this study, rail and deck (unballasted) are linked with a multilinear elastic spring as recommended in UIC 774-3R and other boundary conditions as per IRS & IRC standards. This paper discusses the behavior of structure from the results of the rail stresses and forces to the substructure due to thermal and live load effects at both level Metro Rail system and Highway Road systems.