Bridge Maintenance Costs Research Articles

An IoT-Based Road Bridge Health Monitoring and Warning System.

Recent earthquakes worldwide have led to significant loss of life and structural damage to infrastructure, especially road bridges. Existing bridge monitoring systems have limitations, including restricted detection capabilities, subjectivity, human error, labor-intensive inspections, limited access to remote areas, and high costs. Aging infrastructures pose a critical concern for organizations and government funding policies, showing signs of decay and impending structural failure. To address these challenges, this research proposes an IoT-based bridge health status monitoring and warning system that is wireless, low-cost, durable, and user-friendly. The proposed system builds upon engineering standards and guidelines to classify bridge health status into categories ranging from excellent to collapse condition. It incorporates deflection, vibration, temperature, humidity, and infrared sensors, combined with IoT and a fuzzy logic algorithm. The primary objective is to reduce bridge maintenance costs, extend lifespans, and enhance transportation safety through an early warning system via a mobile application. Additionally, a Google Maps interface has been developed to display bridge conditions along with real-time traffic video. To validate the proposed system, a 3-D prototype model was constructed and tested. Practical testing of the fuzzy logic algorithm aligned with the simulation outcomes, demonstrating expected accuracy in determining bridge health status.

A Comparative Study of a Fully-Connected Artificial Neural Network and a Convolutional Neural Network in Predicting Bridge Maintenance Costs

The cost assessment of bridge maintenance is a difficult topic to study, but it is critical for a bridge life cycle cost analysis. The maintenance costs sample database was established in this study according to actual engineering data, and a bridge maintenance cost prediction model was developed using a fully-connected artificial neural network (ANN) and convolutional neural network (CNN), respectively. First, eight main factors affecting maintenance costs were evaluated based on the random forest method, and the evaluation results were verified by an exploratory data analysis. The original data were then screened based on the isolation forest principle, and the recent gross domestic product (GDP) growth rate was used to illustrate the relationship between economic development and bridge maintenance costs. Finally, these two neural networks were used to establish maintenance cost prediction models, respectively. The results from the two models were compared and their prediction accuracies were analyzed. The prediction performance of the CNN model for bridge maintenance costs was found to be better than that of the traditional fully-connected ANN model. The results of this study will enhance the opportunity for bridge managers to balance lifecycle maintenance costs.

Prediction of Remaining Life for Bridge Decks Considering Deterioration Factors and Propose of Prioritization Process for Bridge Deck Maintenance

Aged highway bridges have become substantially prevalent in recent years. Moreover, combined deterioration, caused by using deicing agents in winter, has led to increased bridge maintenance costs. Accordingly, to extend the service life of bridge decks, this study utilized actual inspection data and major deterioration factors to derive the remaining service life of bridge decks. Based on this study, the following three factors are selected: deicing agent exposure grade, pavement condition state, and surface improvement status. Performance degradation curves were derived for 11 cases that considered the representative three deterioration factors, and the performance degradation of decks was examined for each deterioration factor. Additionally, a process to determine maintenance priorities, using the current condition of highway bridges and the deterioration factors of individual bridges, was proposed. The maintenance demand was predicted based on the end of deck life, which indicated that the demand for deck replacement will sharply increase in 15 years, and that the decks of more than 2000 bridges will reach the end of life in 40 years. Furthermore, this paper proposes a process for prioritizing the maintenance of approximately 9000 highway bridge decks. By applying the prioritization process for bridge deck maintenance to the bridge deck, not only can the life of the bridge deck be extended, but also environmental pollution can be minimized. Additionally, an optimizing design for bridge decks, by considering the remaining life and deterioration factors, can be possible. Therefore, it is expected that the sustainability of the bridge deck can be accomplished.

Theoretical Modal Characteristics of Integral Abutment Bridge With Bored Piles Foundation

Since 2008, the Public Works Department of Malaysia had adopted the integral abutment bridge concept as one of the initiatives to reduce the maintenance costs of bridges. Although this type of bridge is popular in the developed country such as United States, United Kingdom and Japan, the use of integral bridges in the South East Asia Country is considered relatively new. While most of the researches focussed on theoretical dynamic characteristic of bridge founded with H-piles, this paper presents the theoretical dynamic characteristics of integral bridge abutment with bored piles determined by the FE modal analysis performed by using ABAQUS software. A single-span integral bridge located in Pahang, Malaysia has been selected as the case study. The modal characteristics of the same design of bridge with simply supported bridge yield different values of modal frequency, which are higher. From the FE modelling result, it was found that the integral bridge with the bored piles type of foundation possess lower natural frequencies compared to the simply supported bridge of similar type of foundation.

Allocation of bridge maintenance costs based on prioritization indexes

DOI: 10.7764/RDLC.18.3.568 Prioritization indexes (PI) are a need-based bridge maintenance approach, which allows making short-term maintenance decisions. They generally use just the bridge condition as an explanatory variable, therefore, prioritizing is easy to do. When these indexes are multidimensional, prioritization depends not just on the bridge conditions, but also on variables such as vulnerability and their strategic importance. This paper discusses a simple and direct procedure to allocate bridge maintenance costs by using a PI based on the bridge condition, their strategic importance and vulnerability. The procedure combines maintenance activities within the strategies of routine and preventive maintenance, repair, reinforcement, reconstruction or replacement. It includes the calculation of maintenance costs by maintenance activity and strategy, in order to integrate them in a cost matrix. The procedure is applied to a 24-m long bridge, whose infrastructure is made of concrete, steel beams and concrete deck. Unit costs of 60 maintenance activities were calculated, and a sensitivity analysis was carried out to establish the cost by linear meter in relation to PI explanatory variables. The cost was sensitive to bridge condition, their vulnerability, and relevance within the road network.

Integration of Structural Health Monitoring and Intelligent Transportation Systems for Bridge Condition Assessment: Current Status and Future Direction

Recent catastrophic bridge failures clearly indicate the urgent need for improving interval-based bridge inspection procedures that are qualitative and subjective in nature. Structural Health Monitoring (SHM) can mitigate the deficiencies of interval-based inspection techniques and provide real-time diagnostic information regarding the bridge structural health. SHM is not flawless however; the variability in the vehicle characteristics and traffic operational conditions makes it prone to false diagnosis. Recent advancements in the integration of SHM with intelligent transportation systems (ITS) demonstrate the successful use of ITS devices (e.g., traffic cameras, traffic detectors) in the analysis of bridge responses to multimodal traffic with varying loads or during the critical events that cause excess vibration beyond the normal limit. In an ITS-informed SHM system, the ITS device collected data can be integrated with SHM to increase the reliability and accuracy of the SHM system. This integration would reduce the possibility of false diagnosis of damages detected by the SHM system (e.g., vibrations caused by heavy vehicles on a bridge could be read by a SHM sensor as a structural health problem of the bridge), which would eventually decrease the bridge maintenance costs. Similarly, in SHM-informed ITS system, SHM sensors can provide data on bridge health condition for ITS applications, where ITS uses this bridge health condition information for real-time traffic management. In this paper, literature related to both ITS-informed SHM and SHM-informed ITS is reviewed. Based on the literature review, potential challenges and future research directions associated with ITS-SHM integration are also discussed.

효율적인 도심지 교량관리를 위한 교량자산관리 체계 및 서비스수준(LOS) 개발을 위한 기초연구

사회기반시설물의 핵심 시설물 중 하나인 교량은 이용자들이 쉽게 접하고 이용하는 시설물로 일정 수준이상의 성능유지는 필수적으로 요구된다. 교량건설 역사가 상당히 오래된 호주, 뉴질랜드, 미국, 유럽 등의 최근 관련 연구보고서 등의 사례를 비추어 보았을 때, 우리나라 또한 교량의 기대수명에 도달하는 10-20년 내 교량의 유지관리 및 개축 수요가 급격하게 증가될 것으로 예상되므로 비교적 건전한 상태를 유지하고 있는 현 시점에서 한정적인 예산을 효율적으로 분배하기 위해 교량 성능을 적정 수준 이상으로 유지하며 LCC 측면에서의 비용은 최소한으로 투입하는 합리적이고 공학적인 의사결정방법론이 필요하다. 이러한 목적을 달성하기 위하여 호주, 뉴질랜드 및 미국 등에서는 오래전부터 자산관리체계를 마련하기 위하여 많은 노력이 이루어지고 있다. 본 논문에서는 모든 교량을 관리할 수 있는 범용적인 자산관리체계와 교량이 제공하는 서비스수준(Level of Service)과 이를 측정하기 위한 성능측정기준을 개발하기 위한 사전 기초연구로써 연구의 범위를 도심지의 교량으로 한정하여 그 자산관리체계와 서비스수준을 개발하고자 한다. 전문가와 이해관계자로 구성된 워크숍을 실시하여 국내 실정에 맞는 도심지 교량자산관리체계와 그 서비스수준(LOS) 및 성능 척도(PM)를 개발하고 다속성 효용이론(Multi-Attribute Utility Theory)와 AHP기법을 이용하여 성능 지표별 가치의 값과 성능 척도의 가중치 분석을 실시하였다. 도출 된 성능 척도의 가중치와 성능 지표의 가치(Value) 등의 적용 확인을 위해 <TEX>${\bigcirc}{\bigcirc}$</TEX>시의 교량 6개를 선별하여 LOS분석을 적용하고 그 결과를 고찰하였다. Bridges, which constitute one of the key facilities in a social infrastructure, are easily accessed and used by users, so that keeping their performance above a certain level is essential. According to various cases in the U.S., Japan and Europe with a long construction history, it is expected that the maintenance cost of bridges in Korea will increase continuously in the future, so a rational decision making system based on engineering factors is necessary to optimize the performance of and maintain them by allocating the limited budget efficiently. This study is a preliminary basic study for the purpose of developing a common asset management system for managing all of the bridges and maintaining the level of service provided by them. The scope of this preliminary study is limited to bridges in urban areas. The bridge asset management system for bridges in urban areas, their level of service (LOS) and performance measure (PM) were developed by carrying out a workshop consisting of both experts and stakeholders. The analysis on the weights of the value and performance measure for each performance indicator was carried out by using the multi-attribute utility theory and the AHP method. In order to confirm the application of the weight of the performance measure and value of the performance indicator, six bridges in an example city were selected, LOS analysis was applied and its results were reviewed.

Reliability of bridge decks in the United States

Deterioration of bridge decks in the United States is an important issue due to its major impact on bridge maintenance costs nationwide. In this paper, results of survival (reliability) analyses performed on bridge data for all fifty states and Puerto Rico are presented. Data were obtained from the 2011 National Bridge Inventory (NBI) database. The end of service life is defined as a recorded NBI bridge deck rating of 5. Only non-reconstructed bridges and conventional bridge types and decks were considered. The NBI-derived parameters included in the analyses were age, average daily traffic (ADT), deck surface area, and deck rating. Each state’s data were analyzed separately to assess and compare relative performance among the states. Deck reliability at an age of fifty years ranges from less than 20% to over 90% . The geographic regions with the highest overall 50-year reliability are generally in the northeastern and northern United States.

Bridge Load Rating Using Dynamic Response

Proposed herein is a method for load rating of prestressed box beam (PSBB) bridges based on their dynamic response collected using wireless sensor networks (WSNs). The hypothesis states that the health of a bridge is associated with its vibration signatures. Two WSNs were deployed on a 25-year-old PSBB bridge, and trucks were run with variable loads and speeds for collecting its real-time dynamic response at current condition. Also performed were finite-element (FE) simulations of 3D bridge models under vehicular loads to acquire the representative dynamic response at its newest condition. The bridge model was validated by field testing and numerical analysis. The fast Fourier transform and peak-picking algorithms were used to find maximum peak amplitudes and their corresponding frequencies. The in-service stiffness of the bridge was calculated to determine its load rating, which resembles the actual load rating of the bridge. The application software developed from this research can instantly determine the load rating of a PSBB bridge by collecting its real-time dynamic response. The research outcome will help reduce bridge maintenance costs and increase public safety.

Fatigue behavior and statistical evaluation of the stress category for a steel–concrete composite bridge deck

The maintenance cost of bridges is rapidly increasing since many existing bridges are deteriorating or reaching their design life all over the world. Moreover, as many long-span bridges are under construction and planning in Korea, research and development on bridge decks with high load-resistance capacity as well as high fatigue strength has become a growing concern. This research gives experimental results of the fatigue behavior of a new-type of steel–concrete composite bridge deck being developed under such circumstances. The proposed composite bridge deck consists of corrugated steel plate, welded steel ribs, stud shear connectors, and reinforced concrete filler. Fatigue tests were conducted under a four-point bending test with four different stress ranges in constant amplitude. In order to determine the influence of the concrete filling, fatigue tests on partial steel specimens containing only plain corrugated steel plates were performed in advance. The partial steel specimens and the steel–concrete composite deck specimens both showed fatigue failure in the tension part concerning the fillet welding part between the corrugated steel plate and steel rib. Finally, the stress category of the fillet welding part of each specimen is evaluated based on a statistical approach of Albrecht’s probability model. The research concludes that the fatigue behavior of such steel–concrete composite decks under sagging moment can be estimated based on the classical S–N approach, focusing on steel components.

Validation of Design Recommendations for Integral‐Abutment Piles

Because integral‐abutment bridges decrease the initial and maintenance costs of bridges, they provide an attractive alternative for bridge designers. The objective of this project is to develop rational and experimentally verified design recommendations for piles in these bridges. Field testing consists of instrumenting two bridges in Iowa to monitor air and bridge temperatures, bridge displacements, and pile strains. Core samples are also collected to determine coefficients of thermal expansion for the two bridges. Design values for the coefficient of thermal expansion of concrete and revised temperature ranges for the deck and girders of steel and concrete bridges are recommended. A girder extension model is developed to predict the longitudinal bridge displacements caused by changing bridge temperatures. The pile is idealized as an equivalent cantilever. The frame model better predicts both the longitudinal displacement and weak‐axis pile strains. A lateral frame model is presented to predict the lateral motion of skewed bridges. Two alternatives for the pile design are reviewed: the first alternative, the more conservative, includes thermally induced stresses; the second neglects thermally induced stresses but allows for inelastic redistribution of forces.

Prefabricated Press-Formed Steel T-Box Girder Bridge System

The conventional bridge construction methods are time consuming and costly because of the high costs of material and labor. In addition, bridge maintenance costs are increasing rapidly. Hence, the need for more economical techniques of rehabilitating existing bridges and building new ones is well recognized. To this end, several innovative modular bridge systems are being developed by the authors and have been reported in the literature. This paper presents the details of an all-steel superstructure system that is economical and suitable for span ranges of 40 to 100 ft under HS20-44 loading. Herein, it is referred to as the press-formed prefabricated steel box girder-bridge system.