• Proceedings of the KSR Conference
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• 2011.10a
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• pp.374-374
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• 2011

Recently the construction of railway sections passing the central area of cities and stations under railway lines are increasing, and then it is urgently required to take the countermeasures against the railway vibration and the second-phase noise radiated from it. The most efficient countermeasure, out of technologies developed up to now, is the floating slab track which is the track system isolated from the sub-structure by springs. In other countries, the source technologies for anti-vibration design and vibration isolator - one of key components - have been developed and many installation experiences have been accumulated. However, in Korea, since the system design technology and technologies for key components are not yet developed, the foreign system are being introduced without any adjustment, and the key component, vibration isolator, depends on imports. In this study, based on the results of previous studies of the dust-control device installation using the slab and go through time after lifting impressive when stepped on power generated by the cross-section of the slab and shear connection re-examined the structural stability.

• Journal of Korean Society of Steel Construction
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• v.25 no.5
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• pp.531-541
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• 2013

This paper investigated the structural capacity of the CT shear connectors, which is a kind of the perfobond rib and functions as an anchor transferring the tension force in the joint between a composite PHC wall pile and a bottom slab. The direct pull-out test was performed for various specimens. From failure modes and load-displacement curves, it was found that transverse rebars should be placed to holes in a web to restrict pull-out failure of CT shear connectors. The results of additional tests for specimens with transverse rebars and various support lengths indicated that all specimens were failed by the tension failure of PHC pile before pull-out failure of CT shear connector and concrete pull-out failure. Thus, the CT shear connector could endure the tension force between the PHC wall pile and the bottom slab.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.5
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• pp.64-71
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• 2018

This paper provides the results for experimental study on longitudinal shear performance for new-concept composite slabs embedded with silence insulator. Longitudinal shear capacity tests are used to predict characteristics of composite action between the concrete block, silence insulator and deckplate. A total set of 7 Push-Down specimens are tested to clarify the composite action between the concrete block, silence insulator and deckplate. Parameters in this study are the width of T-type bar, the depth of reinforced bar and the thickness of silence insulator. The results from experimental study on longitudinal shear capacity for new-concept composite slabs applied T-type bar, Reinforced bar and Silence insulator are summarized as follows. In test result, the Longitudinal Shear Capacity of the new concept specimen is 2 times excellent than basic specimen with safety. It is expected that applying the proposed composite slab detail at the actual site will provide a significant safety factor in structural aspect of the existing composite slab, and greatly contribute to the improvement capacities of resisting vibration and sound.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.2
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• pp.151-157
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• 2019

Concrete bridge constructed in metropolitan cities has different superstructure members like slabs and girders, and their carbonation depths vary with different design strengths and local environmental conditions. In this paper, 54 concrete cores were obtained from prestressed concrete girders and the related tests were performed for compressive strength and carbonation depth measurement. Referred to the specified compressive strength of 24MPa for slab and 35MPa for I-type girder, the strengths from cores were evaluated to 82% and 73% of design grade, respectively. For carbonation depth, the slab member showed 30.6mm of average with 32.9% of COV(Coefficient of Variation) and I-type girder showed 16.7~17.0mm with 22.8~33.6 of COV. The I-type girder has much lower carbonation depth and COV compared to slab member, however it has higher COV than column structures.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.5
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• pp.37-47
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• 2019

The study purposed to investigate the optimal location of core and offset outrigger system considering floor diaphragm. To accomplish this aim, a structure design of 70 stories building was performed by using MIDAS-Gen. And the leading factors of the analysis research were the slab stiffness, the stiffness of shear wall and the outrigger position in plan. Based on the analysis results, we analyzed and studied the influences of the shear wall stiffness and the slab stiffness on optimal location of core and offset outrigger considering floor diaphragm. The results of the analysis study indicated whether the slab stiffness, the stiffness of shear wall and the outrigger position in plan had an any impact on optimal location in outrigger system of tall building. Also the paper results can give help in getting the structural engineering materials for looking for the optimal position of outrigger system in the high-rise building.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.8
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• pp.169-176
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• 2019

The purpose of this study was to analyze outdoor thermal comfort of apartments planning characteristic of pedestrian height in Beijing, China. Selecting 322 apartment complexes with more than 1000 households and more than 10 buildings(including 10 buildings), mainly in Chaoyang District and Tongzhou District to select 32 basic layout types and then 12 typical layout types were select in 32 basic layout types. Finally, the simulation was conducted for the 12 typical layout types using the micro-climate model ENVI-met to evaluate the wind environment, the thermal environment and the comfort. The results of this study as follows: In the parallel arrangement, it has the best outdoor thermal comfort of Slab-East-Parallel(S/E/P). Next is Slab-South-Parallel(S/S/P), Tower-South-Parallel(T/S/P) in turn. In the stagger arrangement, Mixture-South-North and South Stagger-1(M/S/NSS-1) has the best outdoor thermal comfort and Slab-South-North and South Stagger(S/S/NSS), Tower-South-North and South Stagger(T/S/NSS), Mixture-South-North and South Stagger-3(M/S/NSS-3), Mixture-South-North and South Stagger-4(M/S/NSS-4), Mixture-South-North and South Stagger-2(M/S/NSS-2) in turn. In the cluster arrangement, Mixture-Mixture-Cluster-2(M/M/C-2) has the best outdoor thermal comfort and Mixture-Mixture-Cluster-3(M/M/C-3), Mixture-Mixture-Cluster-1(M/M/C-1) in turn. Due to the low wind speed and high air temperature, it is necessary to consider the layout types that can form the wind road at first, such as Mixture-South-North and South Stagger-1(M/S/NSS-1), Slab-South-North and South Stagger(S/S/NSS) and so on.

• Coupled systems mechanics
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• v.11 no.6
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• pp.557-586
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• 2022

In spite of extensive testing of the individual shear wall and the coupling beam (CB), numerical and experimental researches on the seismic behavior of CSW are insufficient. As far as we know, no previous research has investigated the affectations of position of CB regarding to the slab level (SL). So, the investigation aims to enhance an overarching framework to examine the consequence of connection positions between CB and SL. And, three cases have been created. One is composed of the floor slab (FS) at the top of the CB (FSTCB); the second is created with the FS within the panel depth (FSWCB), and the third is employed with the FS at the bottom of the CB (FSLCB). And, FEA is used to demonstrate the consequences of various CB positions with regard to the SL. Furthermore, the main measurements of structure response that have been investigated are deformation, shear, and moment in a coupled beam. Additionally, wall elements are used to simulate CB. In addition, ABAQUS software was used to figure out the strain distribution, shear stress for four stories to further understand the implications of slab position cases on the coupled beam rigidity. Overall, the findings show that the position of the rigid linkage among the CB and the FS can affect the behavior of the structures under seismic loads. For all structural heights (4, 8, 12 stories), the straining actions in FSWCB and FSLCB were less than those in FSTCB. And, the increases in displacement time history response for FSWCB are around 16.1-81.8%, 31.4-34.7%, and 17.5% of FSTCB.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6D
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• pp.819-829
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• 2008

Fatigue cracking occurs over long time period because dynamic strength of slab continuously decreases by vehicle loading repetitively applied to the concrete pavement. To more accurately predict the fatigue life of the concrete pavement, the stress due to environmental loading should be considered prior to calculating the stress due to the vehicle loading because the stress due to temperature and moisture distribution always exists within the slab. Accordingly, a new fatigue model considering the environmental loading was developed in this research by evaluating factors of existing fatigue models most widely used and by making data points from the models. The applicability of the new model was evaluated by performing a fatigue analysis on the general concrete pavement structure using local climatic and traffic conditions in Korea. It was concluded that the top-down cracking due to the tensile stress at top of the slab is dominant cause of the fatigue failure than the bottom-up cracking occurred at bottom of the slab. More advanced fatigue analysis considering vehicle speed is expected by developing this study.

• Steel and Composite Structures
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• v.52 no.4
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• pp.419-434
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• 2024

A flat slab is a structural system where columns directly support it without the presence of beam elements. However, despite its wide advantages, this structural system undergoes a major deficiency where stresses are concentrated around the column perimeter, resulting in the progressive collapse of the entire structure as a result of losing the shear transfer mechanisms at the cracked interface. Predicting the punching shear capacity of RC flat slabs is a challenging problem where the factors contributing to the overall slab strength vary broadly in their significance and effect extent. This study proposed a new expression for predicting the slab's capacity in punching shear using a nonuniform concrete tensile stress distribution assumption to capture, as well as possible, the induced strain effect within a thick RC flat slab. Therefore, the overall punching shear capacity is composed of three parts: concrete, aggregate interlock, and dowel action contributions. The factor of the shear span-to-depth ratio (a_v/d) was introduced in the concrete contribution in addition to the aggregate interlock part using the maximum aggregate size. Other significant factors were considered, including the concrete type, concrete grade, size factor, and the flexural reinforcement dowel action. The efficiency of the proposed model was examined using 86 points of published experimental data from 19 studies and compared with five code standards (ACI318, EC2, MC2010, CSA A23.3, and JSCE). The obtained results revealed the efficiency and accuracy of the model prediction, where a covariance value of 4.95% was found, compared to (13.67, 14.05, 15.83, 19.67, and 20.45) % for the (ACI318, CSA A23.3, MC2010, EC2, and JSCE), respectively.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.474-479
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• 1998

In this paper, the structural behavior of R.C. multi-layered floor structure including foam concrete layer is numerically analyzed. For the analysis, 3D interface element has been implemented to finite element analysis program to consider the interfacial behavior of multi-layered floor structure which consists of rubber layer, foam concrete layer and mortar layer on RC slab. Based on analysis results on multi-layered structure, its structural behavior is analyzed according to geometrical and material properties of foam concrete. Optimum material property of each layer of the floor structure is proposed to get optimum multi-layered concrete structure.