• 한국철도학회논문집
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• 제12권2호
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• pp.219-229
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• 2009

철도안전법에 의해서 2006년 7월 1일부터 차량운전 및 신호기 등 취급자에 대해서 시행중인 적성검사의 구성체계, 신뢰도 및 적합성을 검증해 보고 향후 적성검사의 방향을 모색하는데 목적이 있다.

• Steel and Composite Structures
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• 제15권1호
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• pp.103-130
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• 2013

Fire performance and fire safety of high-rise buildings have become major concerns after the disasters of World Trade Center in the U.S. in 2001 and Windsor tower in Spain in 2005. Performance based design (PBD) approaches have been considered as a better method for fire resistance design of structures because it is capable of incorporating test results of most recent fire resistance technologies. However, there is a difficulty to evaluate fireproof performance of large structures, which have multiple structural members such as columns, slabs, and walls. The difficulty is mainly due to the limitation in the testing equipment, such as size of furnace that can be used to carry out fire tests with existing criteria like ISO 834, BS 476, and KS F 2257. In the present research, a large scale calorie meter (10 MW) was used to conduct three full scale fire tests on medical modular blocks. Average fire load of 13.99 $kg/m^2$ was used in the first test. In the second test, the weighting coefficient of 3.5 (the fire load of 50 $kg/m^2$) was used to simulate the worst fire scenario. The flashover of the medical modular block occurred at 62 minutes in the first test and 12 minutes in the second test. The heat resistance capacity of the external wall, the temperatures and deformations of the structural members satisfied the requirements of fire resistance performance of 90 minutes burning period. The total heat loads and the heat values for each test are calculated by theoretical equations. The duration of burning was predicted. The predicted results were compared with the test results, and they agree quite well.

• Structural Engineering and Mechanics
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• 제85권4호
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• pp.531-543
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• 2023

The existing concrete bridges are time-varying working systems, where the maintenance strategy should be planned according to the time-varying performance of the bridge. This work proposes a time-dependent residual capacity assessment procedure, which considers the non-stationary bridge load effects under growing traffic and non-stationary structural deterioration owing to material degradations. Lifetime bridge load effects under traffic growth are predicated by the non-stationary peaks-over-threshold (POT) method using time-dependent generalized Pareto distribution (GPD) models. The non-stationary structural resistance owing to material degradation is modeled by incorporating the Gamma deterioration process and field inspection data. A three-span continuous box-girder bridge is illustrated as an example to demonstrate the application of the proposed procedure, and the time-varying reliability indexes of the bridge girder are calculated. The accuracy of the proposed non-stationary POT method is verified through numerical examples, where the shape parameter of the time-varying GPD model is constant but the threshold and scale parameters are polynomial functions increasing with time. The case study illustrates that the residual flexural capacities show a degradation trend from a slow decrease to an accelerated decrease under traffic growth and material degradation. The reliability index for the mid-span cross-section reduces from 4.91 to 4.55 after being in service for 100 years, and the value is from 4.96 to 4.75 for the mid-support cross-section. The studied bridge shows no safety risk under traffic growth and structural deterioration owing to its high design safety reserve. However, applying the proposed numerical approach to analyze the degradation of residual bearing capacity for bridge structures with low safety reserves is of great significance for management and maintenance.

• 한국안전학회지
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• 제9권1호
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• pp.121-126
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• 1994

In this thesis, a series of loading tests are conducted in order to investigate the fracture safety as structural materials of GFRP(Glass Fiber Reinforced Plastics) which we wifely used in the developed countries becauses of their natural of anticorrosion and lightweight etc.. In the fracture test, the mid-span displacement, the strain and the yield load of the GFRP pipes are measured for different number of laminates, and fracture energy is estimated. From this study, it is known that GFRP pipe could be used as structural materials in underground buried pipes if their ductility and strength are increased by controlling number of laminates. Furthermore, because of their merit of lightweight, they can contribute greatly to reduction of construe-tlon cost when they are employed.

• 한국구조물진단유지관리공학회 논문집
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• 제9권4호
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• pp.149-158
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• 2005

본 논문에서는 전통 목조 건축물의 보다 실제에 가까운 구조특성을 파악하고 건물에 대한 안전성을 평가하기 위하여 현존하는 대표적인 전통 목조 건축물인 부석사 무량수전을 대상으로 하여 최대한 실제와 유사한 거동상태가 되도록 건축물을 3차원 및 2차원으로 모델링하여 범용 구조해석 프로그램을 통한 구조해석을 실시한 후에 해석결과를 비교, 분석하고 검토하였다.

• 한국안전학회지
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• 제33권2호
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• pp.86-93
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• 2018

Recently, the use of composite steel plate concrete structural modules filled with concrete between steel plates of complex internal structure, in which a large amount of studs are installed, is increasing in order to reduce the weight and to increase workability of structures such as LNG storage tanks. However, in Korea, there is no systematic criterion for evaluating the construction performance of composite steel plate concrete structural modules. Therefore, in this study, we propose a filling guideline of concrete for composite steel plate structural module. For this purpose, high filling performance concrete with general strength range was formulated and tested for filling ability and permeability for each formulation. Rheology analysis was performed to quantitatively evaluate the flow characteristics of concrete. The reliability of $T_{500}$ and plastic viscosity was evaluated to reflect the results of each test, and a guideline for high filling concrete satisfying the reliability of 0.9 or more was derived by reflecting the results of the study on the relationship between the $T_{500}$ and plastic viscosity. Through final fill-box test, filling performance was verified and guidelines were suggested.

• 한국산업안전학회:학술대회논문집
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• 한국안전학회 2003년도 춘계 학술논문발표회 논문집
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• pp.508-513
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• 2003

The objective of this paper is to investigate the lining board's capacity by using the static loading test and fatigue test. Specimens that constitute the H & Channel type lining board are adopted. The test is to inspect the possibility of retrofit and efficiency, which is required to upgrade the structure's capacity and to examine the effects of the improvements of specimen by using structural analysis, stress analysis, static loading test and fatigue test, respectively. The accumulated test results of stress condition and deflection by bending will be used to analyze the relation between the cause of fatigue crack occurrence and the behavior of both structure system and the steel.

• 한국철도학회논문집
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• 제8권5호
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• pp.419-424
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• 2005

This paper has performed fatigue and nondestructive test of bogie frame for Korean tilting train. Before the fatigue test, static tests were carried out. From the test, the structural safety was investigated using Goodman diagram. After the static test, the fatigue test were conducted under tilting load conditions. The fatigue test was conducted for $10{\times}10^6$ cycles. During the fatigue test, the nondestructive tests using magnetic particle and liquid penetrant were performed at $6{\times}10^6$ cycle and $10{\times}10^6$cycle. From the crack detection tests, it was known that there was no fatigue crack in the bogie frame.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 춘계학술대회 논문집
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• pp.593-598
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• 2009

In this study we present results for the design of ground test system for 4 degree of freedom(DOF) control test is one of the smart UAV ground test. This system is equipped with real smart UAV and Z direction DOF and 3 direction rotation DOF, Ensuring safe operation of the Smart UAV is a top priority. To this end, it is required to do structure analysis and test verification to confirm the design margin and safety. Based on the analysis, the ground test system has been redesigned to meet the structural conditions.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2013년 추계학술대회
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• pp.39-48
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• 2013

Recently, the using of prefabricated temporary equipments is increasing in the industrial field because it can reduce the installation and dismantling period. The various types of prefabricated temporary equipments are manufacturing with various materials in domestic and overseas countries. However, those equipments should win the safety certificate according to the "Governmental Notification about Safety Certification" which regulate the member-based safety certification. It tends to cause over performance of temporary equipments because it couldn't consider structural benefit of the prefabricated products. As the result of this study, it is concluded that the establishment of new safety certification standard for the prefabricated temporary equipments is resonable and the movable scaffold is appropriate for those prefabricated temporary equipment. The movable scaffolds are using as single structure and cannot be expands horizontally. Other types of temporary equipments are using as complex structure which can freely expand horizontally according to the main structure. From the results of the study, the standard of vertical compression performance of prefabricated movable scaffolds should be more than double the performance of single main frame. Other test items of safety certification standard should be fixed when the Notification is amended. The prefabricated temporary equipments which are adopted for the safety standard on assembled structure should be used, moved and kept in assembled state and not separated discretionally. The establishment of new standard for the assembled structure based on this study leads to the development of various types of temporary equipments using structural efficiency of prefabricated structure.