• Journal of Korean Society of Steel Construction
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• v.9 no.3 s.32
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• pp.363-375
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• 1997

This study encompasses the performance of static and fatigue test for the 8 large scale test specimens to clarify the fatigue behavior of coped stringer and the effect of the repair and strengthening on the damaged stringer of the floor system in steel railway bridges. For the purpose of the research, the actual stress wave for the existing bridge was measured, the basic stress range frequency histogram was made and the equivalent stress range was calculated. Using the result from the equivalent stress range made by adjusting the stress range, the static and fatigue test was carried out by identifying the previous rehabilitation and after. As the result of the static tests, it was revealed that the level of local stress under the S1 specimen test of the real equivalent stress range was similar to tensile strength of the test material, and it was consistent with the requirement of the initiation condition of the fatigue crack. Through the various rehabilitation methods to the damaged specimens, the effects of the repair and reinforcement were analyzed. According to the results of the repair of effect, bolting the high tension bolt over the stop hole was confirmed to be more adequate method than drilling only stop hole to delay the fatigue crack growth. Futhermore, in case of the stringer subjected by bending moment, the reinforcement over the upper flange side was determined to be a useful strengthening method, and the reinforcement to the web of the stringer was not appropriate to accomodate as a adequate strengthening method. Also it was confirmed that the category of the fatigue design for the coped stringer met with the category E specified on the fatigue design criteria of the Highway Standard Specification in Korea.

• Journal of the Korea Concrete Institute
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• v.14 no.6
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• pp.922-933
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• 2002

Since the deterioration of concrete bridge decks affect durability, safety, and function, structural rehabilitation of damaged concrete deck that was strengthened with Fiber Reinforced Polymer(FRP) is increasing the latest. But recent studies on the strengthened structures are focused on the static behavior, however only a few studies on the fatigue behavior are performed. In this study, static and fatigue behavior of strengthened deck were peformed on 11 deck specimens strengthened with sheet typed Glass Fiber Reinforced Polymer(GFRP) that were reinforced by two different strengthening methods for the static test. A amount of strengthening material in the each direction such as transverse and longitudinal was adopted experimental variables for the static test and also the stress level of the static maximum load are adopted for the fatigue test. By the results of the experimental study, with respect to the strengthened decks, the resistance effect of crack propagation and effect of stress distribution are improved. In addition, the rate of variation of compliance decreased.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.4
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• pp.135-143
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• 2004

In this paper, 6 span SCP continuous girder bridge's structural behavior were studied by analytic and experimental method To study structural behavior of SCP girder, we used PSC theory and steel girder theory. To examine slab concrete crack, concrete stress, and fatigue stress of steel, we achieved a static load and fatigue test. In the result, 6 span SCP girder bridge connected at the interior support about actuality bridge have enough structural capacity under service loads.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.2
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• pp.54-63
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• 2014

Corrugated steel plate structure, which is built by assembling corrugated steel plate segments with bolts on site and filling the surroundings with quality soil, is widely used for buried structures as a eco-corridors, small bridges, and closed conduits. This experimental study is dealt with the static and fatigue performance of bolt connected corrugated steel plates under flexural loading. The experimental variables to verify the fatigue performance are bolt diameters and detailing of connection such as washer and the corrugation dimension of specimens has a $400{\times}150$ mm. The experimental ultimate strength of specimens under static loading was higher than the theoretical strength and all specimen failed by a bearing and tearing failure of bolt hole of upper plate. Therefore, a fatigue tests of specimens had 6.0mm and 7.0mm thickness was conducted in which the load range was up to 209kN and 516kN, respectively. From the fatigue test, failure patterns are changed from plate bearing and tearing which is a typical failure pattern of static failure to a bearing failure of plate and shear failure of bolt, and experimental fatigue limit at $2{\times}10^6$cycles is about 85MPa.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.2
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• pp.15-21
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• 2011

It is required to accumulate experimental datum that make the theories easy to general technicians in order to use composite material widely on construction field. Therefore, we intend to present base technologies that evaluate static and fatigue performance according to the FRP deck section and offer the basis datum for FRP deck analyses and the design standards. As results of static tests, it can be shown that specimen with fabric direction has higher rigidity than that with normal to fabric direction and convergence for the datum. Due to this reason, it has more stable behavior by structural characteristics of matrix arrangement during destruction. For the fatigue tests, we found that by increasing the number of test repetition, test specimen with fabric direction had an crack just before the destruction, and the contact surface was detached.

• Journal of Korean Society of Steel Construction
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• v.12 no.3 s.46
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• pp.239-250
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• 2000

This study investigates the mechanical behavior on trough rib to crossbeam joint in orthotropic steel plate decks, specially emphasizing on the effect of diaphragm inside trough rib on the fatigue behavior of slit by static and fatigue tests. In particular, the effects of diaphragm on in-plane stress and out-of-plane stress, stress concentration, propagation of fatigue cracks at the silt are studied. With the result of experiment and numerical analysis, we have estimated the fatigue strength using the nominal stress and hot-sport stress. The details with diaphragm have occurred about 50% stress reduction at trough rib part of trough rib to crossbeam joint than the detail without diaphragm, however, the lower parts of crossbeam have occurred much more stress. Initial crack size or slit have an considerable influence on the propagation of fatigue cracks due to V-notch. The fatigue strength category of the details without diaphragm has higher value than fatigue limit, whereas that of the details with diaphragm is estimated lower than fatigue limit.

• Journal of Korean Society of Steel Construction
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• v.16 no.6 s.73
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• pp.725-736
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• 2004

A new type of girder, called steel-confined prestressed concrete girder (SCP girder), has been developed, which maximizes the structural advantages of concrete, steel, and PS tendon, and improves on the shortcomings of steel plate girder, PSC I-girder, and preflex girder bridge for use in the construction of middle- or long-span bridges. To verify the propriety of design, structural safety, and applicability of this girder, a static load test was carried out (Kim et al.., 2002). Since the main damage typically sustained by steel bridges results from the fatigue caused by the repetition of traffic loads, fatigue safety must therefore be guaranteed in applying the SCP girder in the construction of real bridges. In this study, a fatigue test was carried out to investigate fatigue behavior and provide basic data for fatigue design. Based on the fatigue test, the fatigue safety of the girder was estimated. For the fatigue test, 10-m specimens were designed for a standard-design truckload (DB-24). A static load test was also performed before the fatigue test to analyze the structural behavior of the specimens. After the fatigue test, outer steel plates were removed to observe the condition of the concrete in the girder.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.1
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• pp.127-135
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• 2005

Recently, as the concrete structures are becoming bigger, higher, longer and more special, high strength concrete is demanded. But the fracture behavior of high strength concrete is shown more brittle than that of the normal strength concrete. Therefore, in order to improve the brittle fracture behavior and crack propagation resistance, ACI Committee363 has been recommend the use of fiber reinforced concrete which showed superior property against the crack propagation resistance. On the other hand, bridges, concrete pavements and railroads etc. have been exposed to the repetition loading at least several million times during the service life. Therefore, fatigue load is dominantly most of all, but it is very difficult to estimate the suitable fatigue strength calculated by fatigue load. In this research, in order to examine the fatigue behavior of hybrid fiber reinforced high strength concrete, the static and fatigue tests were carried out. And from these results, it was estimated the fatigue strength of hybrid fiber reinforced high strength concrete.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5A
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• pp.873-880
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• 2006

PSC composite bridge with precast decks which was designed by the proposed horizontal shear equation was fabricated. Fatigue test was performed to evaluate the endurance of shear connection and the behavior of PSC composite bridge. After all the fatigue loading were applied, no crack and no residual slip were occurred. The flexural stiffness of PSC composite bridge was maintained the initial value, and demage of shear connection was not occurred. To verify the applicability of horizontal shear equation and shear connection detail and to evaluate the strength of PSC composite bridges, static test was also executed. PSC composite bridges with precast decks had 2.08 safety factor which was the ratio of crack to serviceability load and showed ductile behavior after ultimate load. Test results showed that the proposed design equation of the shear connection gave reasonable horizontal shear connection design. Fast and easy construction would be achieved using the suggested precast system.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.3
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• pp.167-174
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• 2008

The objective of this study is to verify whether the composite action is sufficiently strong to withstand at the interface and the structural behavior of LB-DECK panel with field concrete slab strengthened with main reinforcing bars. Static and fatigue tests are performed for LB-DECK panels with varied shapes and amounts of rebars, and the results are compared with those of field concrete panel(FCP). The test results indicate that the LB-DECK panel with 1.5 times of more rebars inside significantly increase the overall stiffness. LB-DECK penel usually shows on average 52.1 percent of improved stiffness compared with the FCP. The fatigue test results also show that the LB-DECK panel can withstand two-million cycles of repeated loads without any damage.