• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.10a
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• pp.304-313
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• 2000

This study presents the behavior of traditional wood structures of national heritage under earthquake loadings. A series of experimental program for four wood frames was performed to investigate characteristics of initial stiffness, behavior after ultimate loads, and hysteretic behaviors. The frames consisted of columns with a lintel by special joint and a bare frame was infilled by a mud wall. A pushover est was aimed to estimate the range of ultimate rotation of connection as a pilot test for cyclic load tests. One of frames infilled by a mud wall showed a larger stiffness than those of bare frames due to a strut action in the diagonal direction. However, the post yielding stiffness of the infilled frame was not increased.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.10a
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• pp.312-316
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• 1995

Flat-plate buildings are commonly modeled as two-dimensional frames to calculate lateral drift, unbalanced moments, and shear at slab-column connections. For gravity loads. the slab-column frames are analyzed using equivalent column approach, while equivalent beam approach is typical for lateral loads. The equivalent beam approach is convenient for computer analysis, but no rational procedure exists for determining the effective width of foor slabs. At present, the determination of the equivalent slab width and its stiffness is a matter of engineering judgement. To account for cracking, overly conservative assumptions are made regarding the stiffness of the slab. A rational approach is therefore needed to realistically estimate the equivalent slab width and its stiffness for unbalanced moment and lateral drift calculations. Based on the test results of 8 interior slab-column connections, an equivalent beam model is proposed in which columns are modeled conventionally as a function of column and slab aspect ratios and the magnitude of the gravity load. the proposed approach is verified with selected experimental results and is founded to be practical and convenient for analyzing flat-plate buildings subjected to gravity and lateral loading.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1056-1061
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• 2007

Railroad roadbed was consisted into structure types that earthwork, tunnel, bridge and joint sections. Joint section was affected a large factor confidence and safety of the train running by stiffness transition zone that track substructure stiffness change section as like between tunnel and earthwork from ballast track to concrete track. These problems are the results of increased dynamic wheel loads, which also lead to wear and tear on vehicle components and contribute to poor ride quality. The study presented in this paper was conducted on model test by using Wheel Moving Loading System.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.163-167
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• 2001

A two-dimensional progressive failure analysis method is presented for the strength characterization of the composite joints under pin loading. The eight-nodes laminated she]1 element is utilized based on the updated Lagrangian formulation. The criteria by Yamada-Sun, Tsai-Wu, and the maximum stress are used for the failure estimation. The stiffness of failed layer is degraded by the complete unloading method. No factor depending on test is included in the finite element analysis except for the material strength and stiffness. Total 20 plate specimens with and without hole are tested to validate the finite element prediction. The Tsai-Wu failure criterion most conservatively estimates the strength of laminate, and the maximum stress criterion yields the highest strength because it does not consider the coupling of the failure modes. The strength by Yamada-Sun method neglecting the matrix failure effect are located between other two methods and shows best agreement with test result for laminate with hole.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.722-725
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• 2005

Recently, ground-borne noise and vibration generated by underground transit system has been recognized as an important environmental problem. This study reviews several of the improved procedures that have been used to predict ground-borne vibration. At first, ground stiffness profile is examined by SASW test which is the most reasonable surface wave test. It is very important to acquire the exact ground stiffness profile at ground response analysis. At second, the train loading to act roadbed is calculated by using the real measured phase angle data. In finite element analysis, averaged acceleration method, infinite element, Rayleigh damping and 2-dimensional wave propagation analysis is performed.

• Journal of Industrial Technology
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• v.26 no.B
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• pp.101-110
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• 2006

The purpose of this study was to investigate the flexural, interfacial behavior, crack propagation, nonlinear behavior, effect repaired and rehabilitated with VES-LMC using RC beam with 4-point-loading test. The results were following: The test result showed that repair and rehabilitation effect increased as its depth increased, which was verified by the increase of flexural stiffness. More than 40% of stiffness was improved when the depth of repair was up to steel position. However, there was a little difference between 8cm and 12cm repaired beam. This means the repair depth must be considered. The interfacial behavior data showed that the repaired or rehabilitated beams had a little relative displacement. This means that two materials behave comparatively acting together. This suggested that interface treatment were one of the most important jobs in composite beams.

• Steel and Composite Structures
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• v.30 no.4
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• pp.315-325
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• 2019

Double skin composite walls offer structural and economic merits over conventional reinforced concrete counterparts in terms of higher capacity, greater stiffness, and better ductility. This paper investigated the axial behavior of double skin composite walls with steel truss connectors. Full-scaled tests were conducted on three specimens with different height-to-thickness ratios. Test results were evaluated in terms of failure mode, load-axial displacement response, buckling loading, axial stiffness, ductility, strength index, load-lateral deflection, and strain distribution. The test data were compared with AISC 360 and Eurocode 4 and it was found that both codes provided conservative predictions on the safe side.

• Journal of the Korea Institute of Building Construction
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• v.6 no.2 s.20
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• pp.111-117
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• 2006

In case of carrying out vortical crossing water distribution system in expressways or general roads construction, VR(Vibrated and Rolled reinforced concrete) pipes are restricted because of their specification of reinforced spun concrete pipe or on-site made pipe. Therefore, in order to apply VR pipes to those constructions, through the structural behavior experiments of the pipes, VR pipes are compared and verified with reinforced spun concrete pipe and the results are obtained as the following. From the experiments and analyses of Pipe Stiffness(PS) of the pipes, cracking loading is approved to satisfy the KS regulations. Through a direct load test, the cracking loading strength and the maximum load test of VR pipe is larger compared with reinforced spun concrete pipe. Particularly, even if side weld is thin, there is no little change in the cracking strength of VR pipe. The results of the direct load test analysis show that the structural behavior of VR pipe is equivalent or higher compared with reinforced spun concrete pipe in performance and VR pipe could be used as the water distribution pipe for roads. In this study, through pipe stiffness, direct load test and load teat on earth, reinforced spun concrete pipe and VR pipe are compared. And as a result, the structural behavior of VR pipe is comprehensively excellent. From the structural behavior tests, VR pipe's section shows more thickness and has uniform characteristics so that VR pipe is considered more favorable than reinforced spun concrete pipe.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.3
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• pp.303-312
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• 2008

Multi-axial compression tests have been frequently adopted for the evaluation of material properties of rock cores and rock fracture model tests. Special care has to be applied on the boundary condition between the specimen and loading platen to draw the precise test results of the multi-axial compression tests. With the use of dry steel platen, the stress rotation will occur, due to the frictional restraint from the boundary between the specimen and loading platen. The restraint will deviate the expected test results under the conditions of the given external pressures. Various methods have been applied to reduce the side restraint along the specimen/loading platen interface. The steel brush type loading platen is one example of the attempts. In this paper, a new type of loading platen is introduced to overcome the limitation caused by the use of the brush type loading platen, which requires some internal space for the installation of the brushes. The new type of loading platen, roller supported steel piston type loading platen. is constituted of shot steel pistons which have sufficient stiffness to deliver the external pressure and the shaft type roller installed at the rear of the pistons. The pistons are designed to follow the local deformation of the specimens. In this paper, structural details of the loading platen are presented and frictional and biaxial compression tests results are shown to verify the required functions of the loading platen. Furthermore, calibration process is followed by a comparison between the test results and numerical analyses.

• Journal of the Korean Geotechnical Society
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• v.22 no.12
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• pp.89-98
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• 2006

In this paper the behavior of saturated sand deposits where liquefaction occurred before is studied for successive earthquakes. The relationship between past pore pressure generation and reliquefaction resistance is examined by using cyclic direct simple shear tests. If the soil sample in direct simple shear produced nearly 90% of excess pore pressure during first time loading, its liquefaction resistance increased during following cyclic loading after consolidation. However, a fully liquefied soil during first time loading has a densely packed condition but shows less liquefaction resistance for the following cyclic loading. UBCSAND model that can account for pore pressure change and stiffness loss of soil during shaking is used to analyze the centrifuge test simulating reliquefaction. The pore pressure rise during first time cyclic loading controls liquefaction resistance. The measurements from reliquefaction centrifuge test are compared with numerical predictions. By considering frequent earthquakes having occurred at the Southern Korea near Japan, such effective stress approach is necessary for reliquefaction study.