• Structural Engineering and Mechanics
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• 제44권6호
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• pp.839-856
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• 2012

To enable remodeling of the exterior of buildings more convenient, such finishing materials as curtain walls, metal panels, concrete panels or dry stones need to be easily detached. In this respect, this study proposed a new design of the slab for the purposes. In the new design, the sides of the slab were properly modified, and the capabilities of anchors fixed in the modified slab were experimentally tested. In details, a number of concrete specimens with different sizes and compressive strengths were prepared, and the effect of anchors with different diameters and embedment depths applied in the concrete specimens were tested. The test results of the maximum capacities of the anchors were compared with the number of current design codes and the stress distribution was identified. This study found that the embedment depth specified in the current design code (ACI318-08) should be revised to be more than 1.5 times the edge distance. However, with the steel sheet reinforcement, the experiment acquired higher tensile strength than the design code proposed. In addition, for two types of specimens in the tensile strength experiment, the current design code (ACI 318-08) is overestimated for the anchor depth of 75 mm. This study demonstrated that the ideal breakout failure was attainable for the side slot details of a slab with more than 180 mm of a slab thickness and less than 75 mm of an anchor embedment depth. It is expected that these details of the modified slab can be specified in the upgraded construction design codes.

• Steel and Composite Structures
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• 제49권1호
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• pp.19-30
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• 2023

Steel-concrete composite slabs represent a very efficient floor solution combining the key performance of two different materials: the steel and the concrete. Composite slab response is governed by the degree of the interaction between these two materials, mainly depending by chemical and mechanical bond. The latter is characterized by a limited degree of confinement if compared with the one of the rebars in reinforced concrete members while the former is remarkably influenced by the type of concrete and the roughness of the profiled surface, frequently lubricated during the cold-forming manufacturing processes. Indeed, owing to the impossibility to guarantee a full interaction between the two materials, a key parameter governing slab design is represented by the horizontal shear-bond strength, which should be always experimentally estimated. According to EC4, the design of the slab bending resistance, is based on the simplified assumption that the decking sheet is totally yielded, i.e., always in plastic range, despite experimental and numerical researches demonstrate that a large part of the steel deck resists in elastic range when longitudinal shear collapse is achieved. In the paper, the limit strain for composite slab, which corresponds to the slip, i.e., the debonding between the two materials, has been appraised by means of a refined numerical method used for the simulation of experimental results obtained on 8 different composite slab types. In total, 71 specimens have been considered, differing for the properties of the materials, cross-section of the trapezoidal profiled metal sheets and specimen lengths.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.363-366
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• 2003

This study is to develop a strengthening method for RC slab bridges and rigid-frame bridges with external prestressing. In this study, we design the slab specimen that have a strengthening of the DB-13 and set up the longitudinal tendons placed on both side of slab strengthens the whole bridge, and lateral tendons placed under the slab strengthens the middle of slab, and conveys the load at middle slab to both sides. Structural analysis for the tensile force for strengthening were analysed and we know that displacement and strain was improved from this test. This method has no upward roof work, so it is very convenient for installing. And no spaces under the slab are need, so it is good for shallow slabs which has less space inder the slab.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.369-372
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• 2004

The design process of RC Slab includes multiple procedures such as structural analysis, member design, the production of calculation sheets, CAD, and itemized statements of quantities. The objective of this study is to develope an integrated design system that includes all the steps needed for RC Slab design, and as a result, to improve the quality and efficiency of the design process. In this study, the design steps are divided into structural modules and database, and each module and database is systematically combined for the complete design process. The developed design system is based on Web environment. Therefore it can be used in real time and reduces the design work time and space.

• 국제초고층학회논문집
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• 제4권4호
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• pp.271-281
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• 2015

This paper introduces detailed three-dimensional numerical analyses on a bored pile foundation for a high-rise building. A static load test was performed on a test pile and a numerical model of a single pile, which was calibrated by comparing it with the test result. The detailed numerical analysis was then conducted on the entire high-rise building foundation. Further study focused on soil pressures under the base slab of a piled raft foundation. Total seven cases with different pile numbers and raft-soil contact conditions were investigated. The design criteria of a foundation, especially settlement requirement were satisfied even for the cases with fewer piles under considerable soil pressure beneath the base slab. The bending moment for the structural design of the base slab was reduced by incorporating soil pressures beneath the base slab along with bored piles. Through the comparative studies, it was found that a more efficient design can be achieved by considering the soil pressure beneath the slab.

• Computers and Concrete
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• 제22권4호
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• pp.365-372
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• 2018

The current design codes present an equivalent frame method (EFM) for the analysis and design of two-way slab structures. However, since the EFM was developed to be suitable for two-way slab structures subjected to gravity loads only, it brings many problems in its application to the analysis of two-way slabs to which gravity and lateral loads are applied simultaneously. Therefore, authors proposed the unified equivalent frame method (UEFM) that can analyze the structural behavior of flat-plate slab systems subjected to gravity and lateral loads in their previous studies. In this study, the UEFM was modified to be applicable to the two-way slab system with beams. In addition, the accuracy of the proposed UEFM was then examined by comparing it to the lateral behaviors of the two-way slab specimens.

• Steel and Composite Structures
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• 제8권3호
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• pp.217-230
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• 2008

The increasing use of performance-based approaches in structural fire engineering design of multi-storey composite buildings has prompted the development of various tools to help quantify the influence of tensile membrane action in composite slabs at elevated temperatures. One simplified method which has emerged is the Bailey-BRE membrane action method. This method predicts slab capacities in fire by analysing rectangular slab panels supported on edges which resist vertical deflection. The task of providing the necessary vertical support, in practice, requires protecting a panel's perimeter beams to achieve temperatures of no more than $620^{\circ}C$ at the required fire resistance time. Hence, the integrity of this support becomes critical as the slab and the attached beams deflect, and large deflections of the perimeter beams may lead to a catastrophic failure of the structure. This paper presents a finite element investigation into the effects of vertical support along slab panel boundaries on the slab behaviour in fire. It examines the development of the membrane mechanism for various degrees of edge-beam protection, and makes comparisons with predictions of the membrane action design method and various acceptance criteria.

• 한국터널지하공간학회 논문집
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• 제18권5호
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• pp.441-451
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• 2016

본 연구에서는 쉴드 TBM에 의한 대심도 복층터널의 계획 시 세그먼트 라이닝의 거동을 주요 구조물인 내부 슬래브의 연결구조 형식에 따라 검토하였다. 복층터널의 내부슬래브와 세그먼트 라이닝 설계 요구조건을 정립하기 위하여 용도에 따라 내부 구조물의 형식을 정의하고, 터널 라이닝과 내부 슬래브의 연결구조를 비교하였다. 그리고 MIDAS Civil 2012 프로그램으로 빔-스프링 모델을 이용하여 수치해석을 수행하였다. 본 연구결과 중간슬래브 및 하부슬래브, 내부슬래브와 세그먼트 라이닝의 연결 형식 그리고 측압계수들은 복층터널 계획시 주요 설계사항임을 확인하였다.

• Advances in Computational Design
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• 제8권4호
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• pp.295-307
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• 2023

This paper presents an optimization of the reinforced concrete ribbed slab in terms of minimum CO₂ emissions and an economic justification of the final optimal design. The design variables are six geometry variables including the slab thickness, the ribs spacing, the rib width at the lower and toper end, the depth of the rib and the bar diameter of the reinforcement, and the seventh variable defines the concrete strength. The objective function is considered to be the minimum amount of carbon dioxide gas (CO₂) emission and at the same time, the optimal design is economical. Seven significant design constraints of American Concrete Institute's Standard were considered. A robust metaheuristic optimization method called improved dolphin echolocation and ant colony optimization (IDEACO) has been used to obtain the best possible answer. At optimal design, the three most important sources of CO₂ emissions include concrete, steel reinforcement, and formwork that the contribution of them are 63.72, 32.17, and 4.11 percent respectively. Formwork, concrete, steel reinforcement, and CO₂ are the four most important sources of cost with contributions of 67.56, 19.49, 12.44, and 0.51 percent respectively. Results obtained by IDEACO show that cost and CO₂ emissions are closely related, so the presented method is a practical solution that was able to reduce the cost and CO₂ emissions simultaneously.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.375-381
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• 2011

The passage of railway vehicles generates mechanical vibrations and noises. This problem can be mitigated by the 'floating slab track' that isolating from infrastructures by installing vibration isolator in the concrete slab track. In the previous researches, adjacent floating slab tracks are connected by dowel bar system. It has been reported that many dowel bars with less diameter show better load transfer efficiency (LTE) compared to small number of dowel bars with larger diameter under the condition of the same dowel area. In this study, dowel system is further considered as a concrete anchorage system and the design strength of the dowel system was evaluated based on ACI code 318-08 Appendix D. The design strength of dowel system is then verified against failure load test of floating slab system.