Bridge Maintenance Strategies Research Articles

Multi-Objective Optimization for Seismic Structural Investigation and Maintenance Strategies of Bridges in Service

With the continuous updating of seismic design codes for Bridges, the new regulations have higher requirements for the seismic structure and mechanical properties of old Bridges. In order to make the decision of seismic structure strengthening more scientifically, with the goal of optimal overall performance, minimum economic cost and minimum environmental impact, the optimal model of seismic strengthening sustainable strategy is established. Firstly, according to the results of the seismic measures of the existing Bridges, the corresponding reinforcement measures are proposed for the structural problems that do not meet the seismic measures. Then the utility evaluation of the three objectives of the existing bridge was carried out. At last, NSGA-Ⅱ algorithm was used to build a multi-objective maintenance decision optimization model of the bridge network. Combined with the weight of the decision-maker's preference, TOPSIS algorithm was used to obtain the optimal solution of the target, and decision-making suggestions were provided for the relevant departments. The results show that there are many structural problems in the new evaluation of the old bridge, and the maintenance of the structural problems are more feasible and effective than the improvement of the traditional mechanical properties. Combined with the comprehensive evaluation utility and reinforcement objective function, the maintenance decision can be better under different objectives. The reinforcement maintenance decision model has the ability to improve the comprehensive performance and sustainability of the bridge to the maximum extent within the limited budget.

Optimized Bridge Maintenance Strategies: A System Reliability–Based Approach to Enhancing Road Network Performance

Optimized Bridge Maintenance Strategies: A System Reliability–Based Approach to Enhancing Road Network Performance

Analysis of common diseases, monitoring, and maintenance of cable-stayed bridges

The tide of bridge building has passed. Nowadays, the monitoring and maintenance of bridges is very important for their safety, durability, and applicability, and it is the focus of the worlds attention and research. This paper analyzes the common diseases and maintenance strategies of common cable-stayed bridges and cable-stayed bridges in coastal areas. This paper includes system composition, sensor layout, sensor types, monitoring objects, structural health status evaluation, and daily maintenance, as well as Sutong Bridge, Changmen Grand Bridge, and Ganjiang Grand Bridge of Changgan Passenger Transport in Ganzhou and other concrete examples. The modules and functions of structural health status assessment and the application of the bridge health monitoring system, such as early warning and assessment in the daily monitoring of cable-stayed bridges, are introduced. And Changmen Grand Bridge, Ganjiang Grand Bridge of Changgan Passenger Transport in Ganzhou, and Sutong Bridge are compared and analyzed according to the arrangement of measuring points, monitoring objects, and corresponding sensors. Finally, this paper briefly discusses the basic methods of preventive maintenance, BIM, and other related intelligent monitoring methods.

Optimization of Preventive Maintenance Timing of Highway Bridges Considering China’s “Dual Carbon” Target

The dual carbon target is a two-stage carbon reduction goal proposed by China, while the bridge maintenance strategy does not consider the need for sustainable development. Therefore, this article studies the optimization of bridge maintenance timing under China’s dual carbon goals. Firstly, this paper aims to minimize the total cost of maintenance and carbon emissions, considering the continuous effects of carbon pricing and emissions in the context of the dual carbon goals. The CHINAGEM-E model is employed to predict carbon prices, and a preventive maintenance decision-making method for highway bridges is established. Secondly, based on the theory of material residual strength, a degradation model for the technical condition of highway bridges is constructed. Finally, an in-depth case analysis of an in-service highway bridge is conducted to derive optimal maintenance solutions under three scenarios. In comparison to scenarios considering only maintenance costs or those based on benchmark carbon prices, the comprehensive maintenance cost under the dual carbon targets is the highest. In the total maintenance cost, carbon emission costs constitute over 50%, emphasizing the need for increased attention to carbon emission cost studies in future maintenance research. The methodology proposed in this paper is the first to connect carbon prices with the timing of preventive maintenance for bridges, providing a more scientific and sustainable basis for future highway bridge maintenance decisions.

A Big Data Approach for Investigating Bridge Deterioration and Maintenance Strategies in Taiwan

Due to the dwindling maintenance budget and lack of qualified bridge inspectors, bridge-management agencies in Taiwan need to develop cost-effective maintenance and inspection strategies to preserve the safety and functionality of their aging, natural disaster-prone bridges. To inform the development of such a strategy, this study examined the big data stored in the Taiwan Bridge Management System (TBMS) using the knowledge discovery in databases (KDD) process. Cluster and association algorithms were applied to the inventory and five-year inspection data of 2849 bridges to determine the bridge structural configurations and components that are prone to deterioration. Bridge maintenance agencies can use the results presented to reevaluate their current maintenance and inspection strategies and concentrate their limited resources on bridges and components most prone to deterioration.

Information fusion between bridge management system and structure health monitoring system

Through the application status investigation of the bridge management system and the structural healthmonitoring system, it was found that the two systems were not fused well, which resulted in resources waste and inaccurate outcomes. Based on the research of status and application of the two systems, the paper analyzed the necessity and feasibility of the information fusion of the two systems. Finally, the specifie information fusion of the two systems is presented through the exact information fusion of the systems in the bridge structural condition assessment, one of the most important modules of the bridge management system. More accurate results of the condition assessment and remaining life prediction of bridges can be obtained by the bridge management system after the fusion, which will offer some evidence for the bridge maintenance strategy made by bridge management decision- -makers.

Risk-Cost Optimized Maintenance Strategy for Steel Bridge Subjected to Deterioration

This paper aims to develop a deteriorated bridge maintenance strategy that ensures the safe operation of steel structures and minimizes the total risk. Five common failure modes are considered for the deteriorated bridge: flexure, shear, deflection, fatigue failure for girder, and chloride attack for the concrete deck. Time-dependent and system reliability analyses are carried out to find the probability of failure under these failure modes. Risk-cost optimization is then used to determine the maintenance strategy. This method was applied to a working example. It was found that the developed maintenance strategy can predict when, where, and what to maintain for a bridge to ensure its safe and serviceable operation during its lifespan. The proposed methodology can help structural engineers and asset managers repair and maintain bridges under deterioration.

Optimum maintenance of deteriorated steel bridges using corrosion resistant steel based on system reliability and life-cycle cost

Corrosion is a major deterioration mechanism of carbon steel bridges. Multiple maintenance actions have been proposed to meet the safety requirements for bridges subjected to corrosion, including preventive maintenance, such as repainting, and essential maintenance, such as girder replacement. Recently, corrosion-resistant steel has been adopted for bridge construction. However, a comprehensive comparison of different maintenance strategies is still an under-investigated research area, especially for the cost-effectiveness of using corrosion resistant steel to conduct essential maintenance. In this paper, a new type of corrosion-resistant steel, A709-50CR, is considered for girder replacement. Reliability- and risk-based bi-objective optimizations are conducted on a multi-girder carbon steel bridge to determine when and which carbon steel girders should be replaced under different target performance indicators. The objectives are to minimize the life-cycle failure probability/risk and the total life-cycle cost, including initial construction cost and life-cycle maintenance cost. Sensitivity analysis is performed on multiple factors associated with system reliability calculations, such as system models adopted and correlations among resistances of girders. The economic benefits of building an A709-50CR bridge and applying frequent repainting actions on a carbon steel bridge to avoid girder replacement are also investigated. The comparison of different construction and maintenance strategies for multi-girder steel bridges sheds light on their effectiveness.

A Data-Driven Damage Assessment Tool for Truss-Type Railroad Bridges Using Train Induced Strain Time-History Response

ABSTRACT In this paper, a non-parametric damage detection method for truss-type railroad bridges is presented. The method uses operational strain time-history responses to detect damage in truss elements, and change in support behaviour. Dynamic strain time-history responses obtained under baseline and unknown-state bridge conditions are used to compute the magnitudes of differences in strain values between two successive time-steps. A new damage-sensitive feature (DSF) is proposed as the change in percentage of the square root of the sum of squared values of these magnitudes. After establishing a threshold DSF based on the baseline bridge, further structural change or damage in the bridge could be detected and located by observing the values of the DSFs. The validity of the method is investigated through finite element analysis of a steel-truss railway bridge. It is demonstrated that the proposed method yields promising results for identifying, locating, and relatively assessing the damage, and could be useful even when different operational conditions (i.e. different train speeds and loads) and measurement noise influence the strain data. Therefore, the proposed method has the potential to assist in developing effective maintenance strategies for railway bridges.

Optimisation of maintenance strategy of deteriorating bridges considering sustainability criteria

Facing the contradiction between increasing maintenance demand and limited financial, as well as smaller social and environmental impacts, the optimisation of bridge maintenance strategies should be carried out. In this paper, the assessment model of four objectives, including the safety performance, economic, social and environmental impacts, in sustainability criteria are proposed. Moreover, a systematic optimisation framework of maintenance strategy of deteriorating bridges considering sustainability criteria and a novel decision-making method are developed, based on fuzzy analytic hierarchy process (FAHP) and a decision-making algorithm based on linear programming techniques for multidimensional analysis of preference (LINMAP). The case analysis results verify the effectiveness and superiority of the previous optimisation framework, and also show that the final optimal strategy obtained by the proposed decision-making algorithm can reflect the will of experts well. Compare with the essential maintenance, the implementation of preventive maintenance is more conducive to realise the sustainable development of the deteriorating bridges. The sensitivity analysis results show that the monetary discount rate has a greater impact on the life cycle maintenance cost, which is mainly controlled by the total social cost, while the direct maintenance cost only accounts for a small part.

Optimum life-cycle maintenance strategies of deteriorating highway bridges subject to seismic hazard by a hybrid Markov decision process model

Highway bridges are a class of important infrastructure components in transportation networks. Highway bridges will inevitably deteriorate over time due to various external impacts, such as traffic loads and corrosion. In seismic-prone areas, seismic hazard is another critical factor that threatens the normal operation of ageing highway bridges. To ensure adequate safety of ageing highway bridges under potential earthquake shocks, it is imperative to perform proper maintenances during their service life. This paper aims at optimizing the life-cycle maintenance strategies for highway bridges under the combinatorial threats of progressive deterioration and sudden earthquakes. Driven by the distinct characteristics of the two threats, we have proposed a novel hybrid Markov decision process model that integrates a discrete-time Markov decision process model for dealing with progressive deterioration and a continuous-time Markov decision process model for dealing with sudden earthquakes into a unified framework. The proposed model is further reduced into the form of a discrete-time Markov decision process model with an equivalent state transition matrix and an equivalent discount factor, which can be easily solved by dynamic programming. A ternary state space that collectively describes corrosion initiation, corrosion damage cumulation, and seismic damage cumulation is defined. A gamma process and a Poisson process are adopted to model bridge corrosion and earthquake occurrences, respectively. To demonstrate the application of the proposed framework, a numerical example is conducted, in which the optimizations with respect to the maintenance strategy, inspection interval, and design performance level of a hypothetical highway bridge are carried out successively.

Life-Cycle Maintenance Management Strategies for Bridges in Kuwait

To meet the requirements of 21st century, Kuwait ministry of public works have realized that they should use modern technologies and management system to face challenges of modern world. So, they maintenance Administration has launched a massive program which helps to meet development needs and helps to maintain the infrastructure’s sustainable growth. Thus, it is very necessary to develop appropriate bridge maintenance strategies to meet serviceability criteria and life cycle cost optimization of new bridges. And main purpose was to meet the requirements of development needs. Bridge management system (BMS) is a software or we can say a management tool which helps us to maintain or manage the bridges. These are the following main points which helps decision makers to make a best decision. Defines bridge condition, identifies bridge needs for like if we need replacement of any material or renovation can be identified by BMS, cost of bridge during maintenance and management of the bridge, identifies bridges for Replacement and rehabilitation programs (MR & R) and also identifies for the assessment of bridges. According to replacement and rehabilitation programs minor changes or maintenance of the bridges is done by Work management system (WBS). This paper proposes a framework that can enhance the effectiveness of Kuwait’s Integrated Maintenance Management System (KIMMS). A survey for bridge contractors around the world was used as the research method for this study. This contains questions regarding their current bridge management system (BMS) and what are the input and output parameters it considers in the process. BIM (Bridge information modeling) technology is used to reduce the errors in designing and construction of the bridges by using BMS, BRIDGE OWNER may have a sustainability in the maintenance and enhancement of its bridge. We can determine the cash flow to be used in future for the replacement and repairment of bridge. It helps to adopt maintenance program to maintain life-cycle costs for the community. Helps to review the replacement and rehabilitation strategies. Helps to improve the economic life of infrastructure assets. After evaluating the BMSs used by the respondents, it turned out that the most effective procedure should have three main processes to be followed; maintenance planning, maintenance optimization, and maintenance decision support. Overall, the conceptualized framework considers an optimized procedure for maintenance management considering the balance in cost and quality of the process.

Novel methodology for identifying the weight of moving vehicles on bridges using structural response pattern extraction and deep learning algorithms

Acquiring the weights of moving vehicles on bridges is crucial for structural performance assessment, as well as for bridge operating and maintenance strategies. Due to the high cost and complex maintenance structure of the bridge weigh-in-motion (BWIM) system, it is necessary to develop an economic and intelligent technology to replace it. This paper proposes a novel methodology for acquiring the weights of vehicles in motion on a bridge, based on the extraction of structural dynamic response patterns and deep learning algorithms that allow the input of a vehicle to be directly distinguished from the bridge’s output response. The response patterns induced by vehicles crossing a bridge are captured by accelerometers, and the raw signals transformed into two-dimensional spectrogram images via time–frequency analysis to extract corresponding visual patterns. Object classification is then conducted using a deep convolutional neural network (DCNN) to automatically learn the features, while the application of optimal analysis enhances performance of the trained network. Experiments in both a laboratory and in the field were conducted to evaluate the effectiveness of the proposed method with results demonstrating that vehicle loads could be directly distinguished from a bridge’s structural responses, even in a noisy environment.

Effect of temperature on CFST arch bridge ribs in harsh weather environments

In a concrete-filled steel tube (CFST), dry shrinkage and creep produce a circumferential gap between the inner concrete core column and outer steel tube that is increased by harsh weather in cold regions. Thermomechanical coupling finite element analysis was performed to determine the temperature fields, stresses, and strains of CFST arch bridge ribs with circumferential gaps. A traction–separation law was developed for cohesive elements of the steel–concrete interface, which was applied to a parametric analysis on the CFST temperature field and stresses according to diameter. The results can help guide maintenance strategies for CFST arch bridges.

Damage detection framework for truss railway bridges utilizing statistical analysis of operational strain response

In this paper, a non-parametric damage detection method for truss railroad bridges is presented which utilizes statistical analysis of bridge strain responses to operational train loading. Strain time-history responses obtained under baseline and damaged bridge conditions are used to compute the coefficient of variation matrices. The results are presented in terms of the difference of the covariance matrix of the truss bridge between the baseline and damaged condition. The damage in the bridge is detected and located by observing the coefficients of the difference matrix as structural changes occur in the bridge. The magnitudes of the coefficients could be used to relatively estimate the severity of the damage. A finite element model of a truss railroad bridge is utilized for numerical validation of the proposed method. It is demonstrated that the proposed method yields encouraging results for identifying, locating, and relatively assessing the damage even under different operational conditions (e.g., different train speeds and loads). The proposed method could be very useful for early detection of damage and thus could assist in developing effective maintenance strategies for railway bridges.

Performance Degradation Model for Concrete Deck of Bridge Using Pseudo-LSTM

The purpose of a bridge maintenance strategy is to make effective decisions by evaluating current performance and predicting future conditions of the bridge. The social cost because of the rapid increase in the number of decrepit bridges. The current bridge maintenance system relies on traditional man-power-based methods, which determine the bridge performance by employing a material deterioration model, and thus shows uncertainty in predicting the bridge performance. In this study, a new type of performance degradation model is developed using the actual concrete deck condition index (or grade) data of the general bridge inspection history database (1995–2017) on the national road bridge of the bridge management system in Korea. The developed model uses the long short-term memory algorithm, which is a type of recurrent neural network, as well as layer normalization and label smoothing to improve the applicability of basic data. This model can express the discrete historical degradation indices in continuous form according to the service life. In addition, it enables the prediction of bridge performance by using only basic information about new and existing bridges.

A Comprehensive Probabilistic Model of Traffic Loads based on Weigh-in-Motion Data for Applications to Bridge Structures

In various efforts to assure safety and serviceability of a bridge structure throughout its lifetime, it is essential to accurately estimate the traffic load effects. Although traffic loads involve large uncertainties and can vary significantly with site-specific traffic environments, bridge design codes and maintenance strategies do not utilize a probabilistic model that can reflect the actual environments and uncertainties of the target bridge. Rapid developments of weigh-in-motion (WIM) technologies now make it possible to collect various types of data describing the characteristics of vehicles and traffic patterns. Based on actual WIM data collected in South Korea, this paper develops a comprehensive probabilistic model describing the characteristics of vehicles and traffic flow so that the traffic load effects of a target bridge can be assessed using a Monte Carlo simulation approach. To describe the characteristics of vehicles and traffic flow in the WIM data, several important random variables are first identified. These key random variables are then incorporated into a comprehensive probabilistic model based on fitted probability distributions and theories of transportation engineering. The developed model is successfully verified by comparing the daily maximum total loads estimated using actual WIM data with those estimated using artificial WIM data generated from the model. Furthermore, bridge traffic load effects, e.g., moment and tension, are estimated using the influence lines of an actual cable-stayed bridge in South Korea (the Incheon Bridge) and are compared with those from the live load model of a design code. Finally, a brief parametric study is performed to explore the possibility that a probabilistic model developed by the proposed approach can be used as a generic probabilistic traffic load model capable of estimating the site-specific traffic loads through customizations based on partial measurements and available information regarding the target bridge.

Traffic Sensing Methodology Combining Influence Line Theory and Computer Vision Techniques for Girder Bridges

Collecting the information of traffic load, especially heavy trucks, is crucial for bridge statistical analysis, safety evaluation, and maintenance strategies. This paper presents a traffic sensing methodology that combines a deep learning based computer vision technique with the influence line theory. Theoretical background and derivations are introduced from both aspects of structural analysis and computer vision techniques. In addition, to evaluate the effectiveness and accuracy of the proposed traffic sensing method through field tests, a systematic analysis is performed on a continuous box-girder bridge. The obtained results show that the proposed method can automatically identify the vehicle load and speed with promising efficiency and accuracy and most importantly cost-effectiveness. All these features make the proposed methodology a desirable bridge weigh-in-motion system, especially for bridges already equipped with structural health monitoring system.

Seismic fragility curves for California concrete bridges with flared two-column bents

The increased aesthetic appeal of columns with flares resulted in bridge configurations with flared columns during the 1970–1990 design periods in California. Earthquake reconnaissance reports indicated that the flare is detrimental on the structural functionality of the bridge with some geometric configurations. This research examines the relative vulnerability of bridge configurations with flared and non-flared columns for three-span two-column bent bridges with oblong cross-sections. The numerical model of the columns with and without flare is calibrated with existing experimental results. The calibrated models are used to develop the fragility curves for California bridges. Fragility curves for each bridge class are generated by accounting for the material, geometric, and structural uncertainties, and the effects of column flare on the seismic demand and fragility of bridges are investigated in detail in this paper. Results reveal that the presence of column flare for the case study bridges increases the stiffness and strength of columns because of a low potential of column shear failure, resulting in the reduction of bridge vulnerability and have beneficial effects on the structural functionality. Thus, the flare does not necessarily reduce the seismic performance for all bridge cases and depends on the failure mode associated with the bridge configuration. The fragility curves suggested in this research can be used by stakeholders in deciding the retrofitting and maintenance strategies of bridges with architectural flares.

Life-time reliability based optimization of bridge maintenance strategy considering LCA and LCC

Maintenances are necessary to ensure the safety and serviceability of existing bridges. With the increasing number of existing bridges, maintenances cost a large proportion of financial fund and have significant impact on environment. Implementation of preventive maintenance (PM) could reduce the frequency of essential maintenance (EM) and corresponding cost, leading to considerably lower environmental impact of maintenances. Different from planning of EM, which depends on the structural condition of an existing bridge, PM is periodical. Selection of initial time and time interval of PM will influence the life cycle cost and environmental impact of existing bridges. In this study, a framework for the maintenance scheme optimization of existing bridges based on the genetic algorithm was proposed. Maximum safety, minimum life cycle cost and life cycle environmental impact were taken as optimization objects to find a more rational initial time and time interval of PM of the bridges. To verify the effectiveness of the proposed optimization procedure, a case bridge was selected and the cumulative failure probability, life cycle cost, and life cycle environmental impact of the case bridge with different maintenance schemes were calculated. An optimal maintenance schemes set of the case bridge was obtained. Comparison among the optimal schemes and the scheme without PM was conducted. It can be concluded that PM is of great importance on bridge management. Selection of the initial time and time interval of PM rationally would decrease the bridge's life cycle environmental impact effectively. The reduction of the life cycle cost of the bridge caused by maintenance scheme optimization is not significant. This is because that time value of cost was considered by introducing discount rate into the framework.