• Journal of KIBIM
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• v.6 no.2
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• pp.29-38
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• 2016

Road bridges are deteriorating gradually, and it is forecasted that the number of road bridges aging over 30 years will increase by more than 3 times of the current number. To maintain road bridges in a safe condition, current safety conditions of the bridges must be estimated for repair or reinforcement. However, budget and professional manpower required to perform in-depth inspections of road bridges are limited. This study proposes an estimation model for safety rating of road bridges by analyzing the data from Facility Management System (FMS) and Yearbook of Road Bridges and Tunnel. These data include basic specifications, year of completion, traffic, safety rating, and others. The distribution of safety rating was imbalanced, indicating 91% of road bridges have safety ratings of A or B. To improve classification performance, five safety ratings were integrated into two classes of G (good, A and B) and P (poor ratings under C). This rearrangement was set because facilities with ratings under C are required to be repaired or reinforced to recover their original functionality. 70% of the original data were used as training data, while the other 30% were used for validation. Data of class P in the training data were oversampled by 3 times, and Repeated Incremental Pruning to Produce Error Reduction (RIPPER) algorithm was used to develop the estimation model. The results of estimation model showed overall accuracy of 84.8%, true positive rate of 67.3%, and 29 classification rule. Year of completion was identified as the most critical factor on affecting lower safety ratings of bridges.

• International Journal of Highway Engineering
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• v.19 no.6
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• pp.105-115
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• 2017

PURPOSES : The occurrence of unexpected disasters, including fire events, increases as the road network becomes complicated and traffic volume increases. When a fire event occurs on and under bridges, the damage extensively influences direct damage to structures, vehicles, and human life and secondary socioeconomic issues owing to traffic blockage. This study investigated potential fire-hazard risks on bridges of the Korean national route road. METHODS : The investigation was conducted using field investigation and analysis with satellite pictures and road views from commercial websites and the Bridge Management System (BMS). From the filed investigation, various potential fire resources were identified. The satellite pictures and road views were helpful in measuring and recognizing conditions underneath bridges, stowage areas, etc. RESULTS : There are various potential fire resources underneath bridges such as piled agricultural products, parked petroleum tanks, construction equipment, and attached high-voltage cables. A total of 94.6% of bridges have underneath clearances of less than 15 m. A bridge underneath volume that can stow a potential fire hazard resource was $7,332m^3$ on average, and most bridges have about $4,000m^3$ of space. Based on the BMS data, the amounts of PSC and steel girders were 29% and 25%, respectively. CONCLUSIONS : It was found that the amount of stowed potential fire hazard resources was proportional to the underneath space of bridges. Most bridges have less than 15 m of vertical clearance that can be considered as a critical value for a bridge fire. The fire risk investigation results should be helpful for developing bridge fire-protection tools.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.157-162
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• 2004

Recently, Life Cycle Cost (LCC) for civil infrastructures, such as pavements, bridges, and dams, has been emphasized. However there are few cost models for road tunnel especially for maintenance phase. The road network is composed of highways, bridges, and road tunnels. Thus it is as important as for road tunnels to keep safe for traffic. The maintenance strategies for road tunnels can be achieved based on the minimization of LCC in maintenance phase. For this purpose, in this paper, cost model and cost classification for road tunnel in maintenance phase are suggested.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.757-767
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• 2016

The power spectral density (PSD) for the road surface roughness on the bridges of minor roads in Wonju city and Hoengseong-gun, Gangwon-do is presented. To obtain the PSD, the road surface roughness on 18 different bridges with various superstructure type and span is measured by GPS at every 10 to 30cm interval. Assuming the PSD as the stationary normal probability process with zero mean value, the PSD of measured road surface roughness is obtained by applying the Maximum Entropy Method (MEM). A simple formula in evaluating the PSD of RC slab bridge, Rahmen bridge and PSC I-girder bridge which is applicable to the dynamic response analysis of bridges considering the road surface roughness is proposed. Using the calculated PSD curves, the road surface conditions on the 18 bridges are evaluated. The statistical relationship between the PSD and the IRI is presented by applying linear regression and correlation analysis.

• Journal of the Korean Society for Railway
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• v.8 no.5
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• pp.439-443
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• 2005

The biggest challenge bridge agencies face is the maintenance of bridges, keeping them safe and serviceable, with limited funds. To maintain the bridges effectively, there is and urgent need to predict their remaining life from a system reliability viewpoint. In this paper, a model using lifetime functions to evaluate the overall system probability of survival of a rail road bridge is proposed. In this model, the rail load bridge is modeled as a system. Using the model, the lifetime of the rail road bridge is predicted.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1989.04a
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• pp.11-16
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• 1989

This paper presents a fatigue reliability model for the reliability-based evaluation of remaining fatigue life of existing rail-road bridges. It is demonstrated that the simple fatigue reliability model based on the Weibull distribution of fatigue life can be extended by incorporating various effects due to the rate of the train-traffic increase and in-service Inspections. The paper also suggests the system fatigue reliability analysis using an approximate formulation and 2nd-order bound solutions. The application of the proposed model to existing rail-road brdiges based on field load tests shows that it may be practically used for the assessment of fatigue reliability, remaining life, and in-service inspection scheduling of existing rail-road bridges.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1997.04a
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• pp.185-191
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• 1997

The study presents the linear dynamic analysis of bridges under vehicular movement to examine the performance characteristics due to the various structural and loading conditions. The road surface roughness and bridge-vehicle interactions are considered. The road surface profiles for the approaching roadway and bridge decks are generated from power spectral density functions for different road roughness conditions. A new filtering method using the wheel trace is proposed to obtain the more rational bridge-vehicle interactions from the randomly generated road surface. The dynamic responses of various bridges designed according to current design practice are examined, in which important structural parameters(such as span length, girder spacing, etc.) are considering systematically. In addition, the traffic conditions of multi-truck traveling either consecutively on the same lane or side-by-side on the adjacent lanes are also evaluated.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1166-1169
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• 2009

Bridges are exposed to very severe environment and experience, as service life increased, elevated traffic load and traffic flow, in addition to natural disasters. In comparing to other road structures, bridges may cause more significant damage, such as human-involved accidents, to the society in the event of collapse. A certain level of service shall be necessarily secured to assure the minimum safety of users. The cost for manage and preserve bridges will increase gradually and more restrictions will be loaded to efficiently distribute the limited resources, such as monetary budget and human resource etc. In order to enhance performance and serviceability of bridges with the limited resource, asset management technique has been applied into the bridge management system, which capitalizes the road infrastructures including bridges and assess them in accordance with the government finance report. In the application of asset management, there must be a tool for assess the performance of bridges and this study introduces the basic information on the definition and role of performance measures for asset management for bridges. This research suggests future development direction of performance measure for asset management for bridges in Korea.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.3 s.49
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• pp.135-147
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• 2006

The essential information elements for the Earthquake Damage Evaluation System (EDES) of highway bridges are defined in this study, and a database construction method, which fits the circumstances of Korea, is proposed. The information elements for the EDES of highway bridges are categorized in two groups: structure related information, location related information. The structure related information is composed of the fragility curve information which is necessary for earthquake damage evaluation of highway bridges. The data structure of road network, which represents the location related information, is defined in more detail than the existing GIS-based data structure of road network for modeling of junctions. A pilot GIS-based EDES subjected to 110 bridges on expressway in Korea is developed, and it is verified that the proposed database construction method for the EDES can be used to develop a decision making system for quick retrofitting of the seismic damages of highway bridges and road network.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.498-501
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• 2006

R.C. Rahmen bridges have been widely constructed in the location of interchange or narrow road crossing. In addition, skewed or curved rahmen bridges are mostly constructed in comparison with normal rahmen bridges for the purpose of maintaining the route of road or considering the beauty of bridge. However, due to the functional characteristics, rahmen bridges are sustained under the direct vehicle loads and the side directional earth pressure so that the stress concentration with respect to the geometrical eccentricity can be occurred if rahmen bridges are constructed in large amount of skew. In this investigation, the behavior of skewed rahmen bridges which is located in curved route has been analysed to investigate the additional effects on the change of stress concentration. As a result, it is judged that the stress of curved rahmen bridges is more concentrated than the stress of straight rahmen bridges in the region of obtuse angle. However, in the middle of slab, the curve does not affect on the stress concentration.