• 한국터널지하공간학회 논문집
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• 제19권5호
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• pp.717-732
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• 2017

최근 급증하는 도로 교통량을 원활히 처리할 수 있는 대안으로 복층터널과 같은 지하구조물의 건설이 증가하고 있다. 복층터널은 내부에 상부와 하부를 분리하는 중간슬래브가 존재한다. 중간슬래브는 차량이 주행할 때 발생하는 차량의 동적하중으로 인하여 동적거동을 하게 되며, 그 동적거동을 정확히 파악하여 설계 및 해석에 이용하는 것이 중요하다. 본 연구에서는 복층터널 중간슬래브의 구조형식, 설계속도, 주행차량 및 노면조도 등을 고려한 해석모델을 작성하고 노면에 차량이 일정속도로 주행하는 경우에 대해 3차원 동적해석을 수행하여 복층터널 중간슬래브의 동적거동을 분석하였다. 그 결과, 중간슬래브의 동적영향을 대표하는 동적확대계수는 탄성받침 지지조건 및 보통의 노면조도 조건에서 가장 크게 증폭되는 경향을 보였고, 양호한 노면조도와 강결연결 조건에 의해 동적영향을 작게 할 수 있음을 확인하였다.

• 한국구조물진단유지관리공학회 논문집
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• 제1권1호
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• pp.113-124
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• 1997

Based on the recent developments of the reliability-based structural analysis and design as well as the extending knowledge on the probabilistic characteristics of load and resistances, the probability based design criteria have been successfully developed for many standards. Since the probabilistic characteristics depend highly on the local load and resistances, it is recognized to develop the design criterion compatible with domestic requirements. The existing optimum design methods, which are generally based on the structural theory and certain engineering exprience, do not realistically consider the uncertainties of load and resistances and the basic reliability concepts. This study is directed to propose a optimum design based Expected Total Cost Minimization on two-way slab system which could possibly replace optimum design based traditional provisions of the current code, based on the AFOSM reliablity theory.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.753-756
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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, analysis on floating slab system installed rubber mat and stopper is carried for the examination on the safety of floating slab system.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.1229-1234
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• 2001

The bottom slab of Inchon LNG in-ground #213 tank is designed as a massive structure witch has a large depth and section. The purpose of this study is to determine the optimum mix design having good workability and low hydration heat for bottom slab concrete and to control the actual concrete quality in site. For this purpose, we select the optimum mix design used ternary blended cement(furnace slag cement＋fly ash) and design factors. As test results of actual application, we have finish placing the bottom slab concrete of 23,180㎥ during 68hours with good success and obtain the good quality of fresh and hardened concrete including slump, air contents, no-segregation, compressive strength and low hydration heat in actual data. All test results are satisfied with our specifications for bottom slab concrete and we cut costs as the use of ternary blended cement and the reduction of placing hours.

• 한국디지털건축인테리어학회논문집
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• 제8권1호
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• pp.57-64
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• 2008

There are many problems in present truss-deck slab system for example welding defect, segregation, water leakage, rust and tarnish etc. These problems may be caused by spot welding thin galvanized steel plate and lattice bar. The TOX Joining Systems is to join metal sheets of different material and thickness with and without coating or painting without adding heat or a joining part. Newly developed TOX-deck slab system using non-welding joint is free from above mentioned problems. The objects of this study are suggestion of design strength of TOX joint by experimental and statistical analyses and development of window based program to design the TOX-deck slab system.

• Advances in concrete construction
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• 제5권1호
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• pp.49-63
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• 2017

Traditional reinforced concrete slabs and beams are widely used for building. The use of flat slab structures gives advantages over traditional reinforced concrete building in terms of design flexibility, easier formwork and use of space and shorter building time. Deflection of the slab plays a critical role on the design and service life of building components; however, there is no recent research to explore actual deformation of concrete slab despite various advancements within the design codes and construction technology. This experimental study adopts the Hydrostatic Levelling Cells method for monitoring the deformation of a multi-storey building with flat slabs. In addition, this research presents and discusses the experimental results for the vertical deformation.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.537-542
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• 1999

The design methodologies for carbon fiber sheet(CFS) strengthening of RC structures are not well established yet because the structural behavior of strengthened RC structures is more complex than that of unstrengthened ones. Even though the research for the methods using CFS has beed studied, the strengthening effects and structural behaviors of strengthened structures are not systematized yet. The purpose of this study is to carry out the experimental studies on three kinds of half scale RC slab bridges and to investigate the behavior of RC slab bridges from the experimental results. Typical flexural failure occurs in the non-strengthening slab like general RC slab bridges, and also the flexural failure occurs in the all area strengthened slab with sudden rip-off failure of strengthening material by punching shear. For the case of strip type strengthened slab, flexural failure occurs, with rip-off of second strip at the base of loading point. Strengthening effect on the slab using CFS is that the strength is increased upto 7~15 percent and the crack pattern is changed.

• Computers and Concrete
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• 제6권2호
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• pp.109-132
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• 2009

This paper presents finite element impact analysis for the design of Structurally Dissipating Rock-shed (SDR), an innovative design of reinforced concrete rock-shed. By using an appropriate finite element impact algorithm, the SDR structure is modelled in a simplified but efficient way. The numerical results are firstly verified through comparisons with the results of the experiments recently realized by ESIGEC and TONELLO I.C. It is shown that, using this impact algorithm, it is possible to correctly predict the SDR structural behaviour under different rock-fall impact conditions. Moreover, the numerical results show that the slab centre is the critical impact location for reinforced concrete slab design. The impact analyses have thus been focused on the impacts at the slab centre for the SDR structural optimization. Several series of parametric studies have been carried out with respect to load cases and engineering parameters choices. These numerical results support the robustness of the new SDR concept, and serve to optimize SDR structure and improve its conventional engineering design, especially for ensuring the slab punching shear resistance.

• Structural Engineering and Mechanics
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• 제48권5호
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• pp.615-642
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• 2013

In this paper a study on prestressed concrete slab bridges is presented. A design philosophy based on the concept of load balancing through prestressing is proposed in order to minimize the effects of delayed deformations due to creep. Aspects related to the stress redistribution inside these bridges for time-dependent phenomena are analyzed and discussed, by applying the principles of aging linear visco-elasticity. Prestressing is seen as an equivalent external load which counterbalances the permanent loads applied to the bridge, nullifying the elastic deflections due to sustained loads, and thus avoiding the related delayed deformations. An optimization of the structural behavior through the use of one-way prestressing is achieved. The determination of a convenient variable depth of slab bridges and the correspondent layout of tendons is considered as a useful means for applying the load balancing concept in actual cases of structures like long cantilevers or bridge decks. A case-study related to the slab bridges built 30 years ago at Jeddah in Saudi Arabia is presented and discussed, in order to show the effectiveness of the proposed approach to the conceptual design of prestressed concrete bridges.

• Current Optics and Photonics
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• 제4권1호
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• pp.50-56
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• 2020

The design of a concentration system for a solar side-pumped slab laser was investigated. The side size of the slab laser medium is 2 mm × 20 mm. Based on the principle of the edge ray, a secondary concentrating system consisting of a rectangular parabolic mirror (RPM) and a rectangular dielectric-filled compound parabolic concentrator (RDCPC) was demonstrated. The focal length of RPM is 1200 mm and the size is 734 mm × 2000 mm. The outlet size of the RDCPC is 2 mm × 20 mm. The concentration effect was analyzed by using Tracepro optical software. The results showed that the concentration efficiency reached 81.3% and the uniformity of the spot was 91.4% after optimization. This design of concentration system is of great reference value for a solar side-pumped slab laser.