• Journal of the Korea institute for structural maintenance and inspection
• /
• v.1 no.2
• /
• pp.115-122
• /
• 1997

Although most bridge foundations are usually constructed by Caisson, terrain difficulties sometimes bring about constructing bridge foundations by Jacket piles. This study investigated the dynamic characteristics of Caisson and Jacket by testing the impact applied to actual bridge foundations. The test result showed that the damping ratio of the foundation constructed by Jacket and Caisson were measured 1-2% and 3-6%, respectively. Considering the lateral deflection measured by the impact test, the rigidity of foundations constructed by Jacket was assessed about 1/5 - 1/6 of those constructed by Caisson. It implies that designing bridge foundations should include and reflect the dynamic analysis of bridge foundation.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.5 no.1
• /
• pp.169-175
• /
• 2001

Bridge load rating calculations provide a basis for determining the safe load capacity of bridge. Load rating requires engineering judgement in determining a rating value that is applicable to maintaining the safe use of the bridge and arriving at posting and permit decisions. Load testing is an effective means in calculating the rating value of bridge. In Korea, load carrying capacity of bridge is modified by response modification factor that is determined from comparisons of measured values and analysis results. The response modification factor may be corrupted by vehicle location error that is defined as the gap of test vehicle location between load testing and analysis. In this study, the effects of vehicle location error to structural response and response modification factor are investigated, and a new method for evaluating response modification factor is proposed. The random data analysis shows that the proposed method is less sensitive to vehicle location error than the present method.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.2 no.2
• /
• pp.177-184
• /
• 1998

The equation of motion on the vehicle-bridge system is established as the simultaneous equations which are combined the equation of vehicle and bridge by the interaction elements. A vehicle element is modeled as lumped masses supported by springs and dashpots, and a bridge element with pavement roughness is modeled as beam elements. An interaction element is defined to consist of a bridge element and the suspension units of the vehicle resting on the element. By the dynamic condensation method, the degrees of the freedom are eliminated, and compared with all the degrees of freedom on the bridge, the efforts of calculation is decreased. Thus, although a very small computational error is occured, the present technique appears to be computationally more efficient. It is particularly suitable for the simulation of bridges with a series of vehicles moving on the deck.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2008.04a
• /
• pp.532-537
• /
• 2008

Existing management of bridge is being writing management paper at field and computing at office. These are instability factor on bridge structure because of authenticity deterioration, disutility data management. Therefore, this paper is possibility expedient and objectivity inspection considering check situation at field for solve these problem. And development software which is intelligent bridge maintenance based Ubiquitous. This software can increase authenticity of data through computerization of maintenance data and reduce of time. Also, we confirm effective and facilitate maintenance management using ubiquitous.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.6 no.2
• /
• pp.217-224
• /
• 2002

This paper is proposed a reasonable method for determining the dynamic properties, the impact factors caused by traffic loads on highway bridges. In addition, the impact factors obtained in previous inspection reports were classified by the span length of the bridge, kind of bridge and type of bridge and the result of the impact factor was adjusted by a statistical method and presented problems. Also, the method for determining the impact factor using traffic load is proposed and the proposed method is compared with the specification code. The method estimating the impact factors due to the traffic loads can efficiently recognize the response of the structure by providing the impact factors and help to save the investigation cost, and also it can be used for the maintenance of structures using the usual test of bridges.

• Structural Monitoring and Maintenance
• /
• v.10 no.3
• /
• pp.191-205
• /
• 2023

In this paper, through operational modal analysis and ambient vibration tests, the dynamic characteristics of a multi-span simply-supported reinforced concrete highway bridge deck was determined and the results were used to assess the quality of construction of the individual spans. Supporting finite element (FE) models were created and analyzed according to the design drawings. After carrying out the dynamic tests and extracting the modal properties of the deck, the quality of construction was relatively assessed by comparing the results obtained from all the tests from the individual spans and the FE results. A comparison of the test results among the different spans showed a maximum difference value of around 9.3 percent between the superstructure's natural frequencies. These minor differences besides the obtained values of modal damping ratios, in which the differences were not more than 5 percent, can be resulted from suitable performance, health, and acceptable construction quality of the bridge.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.1450-1459
• /
• 2007

Line type rigid bearings for Open-Steel-Plate-Girder railway bridges have several problem in service, and they are unstable structurally. Thus, spherical bearings having advanced maintenance capability and device to resistance up-lift are developed and replace the existing ones. A experiment of maintenance for a new placed spherical bearings under real Open-Steel-Plate-Girder bridge is conducted and their good maintenance performance is proved. The dynamic behavior of the bridge is measured and analyzed for the two cases of the existing and replacing bearings. Therefore, the effect of the new spherical bearings on the railway bridge is assessed.

• Journal of Korean Society of societal Security
• /
• v.1 no.4
• /
• pp.41-49
• /
• 2008

As bridges have been longer and bigger recently, lots of bridge management systems (BMS) have been developed for each bridge. However, the differences among the data models developed by different system developers give a serious problem in integrated information management for national security. The aim of this study is to develop a common data model which can be referred in development of the BMS. The existing BMS and work process by laws are carefully analyzed. Based on the analysis results, the bridge management and maintenance process is categorized into the four basic activity types. In addition, common data models for each the unit activity type are defined.

• Structural Monitoring and Maintenance
• /
• v.6 no.2
• /
• pp.85-101
• /
• 2019

The effects of foundation scour depth and riverbed condition on the natural frequencies of a typical cross-river integral abutment bridge have been studied. The conventional operational modal analysis technique has been employed in order to extract the modal properties of the bridge and the results have been used in the Finite Element (FE) model updating procedure. Two tests have been carried out in two different levels of water and wet condition of the riverbed. In the first test, the riverbed was in dry condition for two subsequent years and the level of water was 10 meter lower than the natural riverbed. In the second test, the river was opened to water flow from the upstream dam and the level of water was 2 meter higher than the natural riverbed. The results of these two tests have also been used in order to find to what extend the presence of water flow in the river and saturation of the surrounding soil affect the bridge natural frequencies. Finally, the updated FE model of the bridge has been applied in a series of parametric analyses incorporating the effect of piles' relative scour depth on the bridge natural frequency of the first four vibration modes.

• Structural Monitoring and Maintenance
• /
• v.2 no.1
• /
• pp.65-75
• /
• 2015

Among the destruction instances of half-through arch bridges, the shorter hangers are more likely to be ruined. For a thorough investigation of the hanger system durability, we have studied vehicle impact effect on hangers with vehicle-bridge coupling method for a half-through concrete-filled-steel-tube arch bridge. A numerical method has been applied to simulate the variation of dynamic internal force (stress) in hangers under different vehicle speeds and road surface roughness. The characteristics and differences in impact effect among hangers with different length (position) are compared. The impact effect is further analyzed comprehensively based on the vehicle speed distribution model. Our results show that the dynamic internal force induced by moving vehicles inside the shorter hangers is significantly greater than that inside the longer ones. The largest difference of dynamic internal force among the hangers could be as high as 28%. Our results well explained a common phenomenon in several hanger damage accidents occurred in China. This work forms a basis for hanger system's fatigue analysis and service life evaluation. It also provides a reference to the design, management, maintenance, monitoring, and evaluation for this kind of bridge.