• 한국재난정보학회 논문집
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• 제19권1호
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• pp.60-68
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• 2023

연구목적: 본 연구에서는 석축단면의 설계를 지배하는 안정성 검토조건과 그에 따라 계산되는 블록 설치 폭의 변화양상을 살펴보고자 하였다. 연구방법: 이를 위해 높이 10m 인 석축을 가정하고 석축을 구성하는 블록 및 지반조건 등에 관해서는 일반적인 설계 값을 적용하여 활동 및 전도를 고려한 석축단면을 결정해보고 그 결과를 비교해 보았다. 연구결과: 설계결과에 따르면 활동에 대한 안정을 고려하여 결정된 블록의 설치 폭이 전도를 고려하여 결정된 블록의 설치 폭 보다 현저하게 작음을 알 수 있었는데 이러한 차이는 활동에 대한 안전율을 전도에 대한 안전율과 같게 적용하더라도 크게 개선되지는 않았다. 전도를 고려하여 블록 설치 폭을 결정하는 방법에는 전도되는 부분의 바닥을 수평으로 보는 방법과 하부의 파괴쐐기를 고려하는 방법이 있는데 석축의 설계를 지배하는 방법은 하부의 파괴쐐기를 고려하는 방법임을 알 수 있었다. 결론: 전도되는 부분의 하부 파괴쐐기를 고려하는 경우 가정한 파괴쐐기의 경사각이 클수록 블록 설치 폭 또한 커짐을 알 수 있었다. 특정한 경사각을 갖는 파괴쐐기를 가정한 벽체에 대하여 벽체 하부에서의 전도를 고려하는 경우 석축의 기하학적 제약조건에 의해 파괴쐐기의 경사각이 감소하게 되어 블록 설치 폭 또한 감소함을 알 수 있었다.

• 한국지반신소재학회논문집
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• 제22권1호
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• pp.53-66
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• 2023

본 연구에서는 대규모 지반굴착 조건에서 흙막이 벽체로 적용된 벽강관말뚝의 탄소성보 해석, 유한요소 해석 및 최적화 설계 등의 결과를 제시하였다. 본 연구를 통해 고강도 내해수강 벽강관의 경우 부식에도 유리하고 허용응력이 커 구조적으로 우수하여 흙막이 벽체로써 활용성이 높고, C-Y형 이음부의 경우 기존 P-P형 대비 인장강도와 강성이 크게 개선되었음을 알 수 있었다. 또한, 시공 중 벽체 누수나 결함이 발생하더라도 용접, 덧댐 시공 등으로 확실한 보수가 가능한 장점이 있는 것으로 조사되었다. 벽강관 연속벽의 경우 CIP나 Slurry wall 대비 변위 순응 구조임과 동시에 동일 수평변위에 대하여 허용 휨응력이 매우 커 대심도 흙막이 측면에서 가장 우수한 것으로 평가되었다. 대규모 편토압 조건에서의 지반굴착임을 고려하여 탄소성보해석 및 유한요소 해석을 실시하고, 그 결과를 상호 비교한 결과, 굴착 시 전체적인 거동, 벽체의 변위나 부재력 등 각 항목별 발생 최대값에 대해서도 두 방법간에는 정량적 수치가 유사한 것으로 나타나 추후 설계 시 두 해석방법 모두 적용가능한 것으로 나타났다. 마지막으로, 동일 직경에서 가장 두꺼운 두께의 중공형보다는 가장 얇은 두께에 콘크리트로 속채움하는 방법, 그리고 변위와 부재력의 급격한 변화가 없는 깊이 즉, 정상성 검토를 통한 근입길이 결정 시 경제적인 설계가 가능함을 알 수 있었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 지반공학 공동 학술발표회
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• pp.49-83
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• 2005

ESCP Project showed an urban excavation case and introduced design method for case of Soil-Structure behavior in urban excavation. In this case, a retaining structures design to analysis the behavior of retaining wall and adjacent structures in urban excavations was applied by using a Elasto-plastic beam and limit Equilibrium analysis and soil-structure interaction analysis. Reliable design of earth retaining structures and the ground adjacent to braced wall in urban excavation are often difficult due to many variable factors. The ground settlement and the damage of adjacent structures in urban excavation has been an imprtant issue. Therefore, the stability of the adjacent structures must be secured with the excavation support and research on the protection of adjacent structure is necessary.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.740-743
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• 2005

Most works of the large vertical ceiling structures have been performed by human manually. These works require much more operation costs, labors and times, etc. Beside most people avoid this works because of it's characteristic such as danger, dirty and difficulty. So necessity of automation for these works has been rising. This automation needs a wall climbing mobile vehicle because of the movement of platform large workspace. In this study, we aim at develop the wheel which can be used for vertical wall-climbing mobile robot using electromagnet wheel. The wheel proposed can be available for several working processes on structures which consist magnetic substance.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.437-440
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• 1999

A numerical study is preformed to investigate behavioral characteristics of T-shaped RC wall that is frequently used for the wall-slab structure system. This study provides design methods to address shear lag and to prevent early failure due to cracking and crushing.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.327-328
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• 2011

• Earthquakes and Structures
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• 제9권4호
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• pp.789-830
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• 2015

The recent re-assessment of the seismic hazard in Europe led for many regions of low to moderate seismicity to an increase in the seismic demand. As a consequence, several modern unreinforced masonry (URM) buildings, constructed with reinforced concrete (RC) slabs that provide an efficient rigid diaphragm action, no longer satisfy the seismic design check and have been retrofitted by adding or replacing URM walls with RC walls. Of late, also several new construction projects have been conceived directly as buildings with both RC and URM walls. Despite the widespread use of such construction technique, very little is known about the seismic behaviour of mixed RC-URM wall structures and codes do not provide adequate support to designers. The aim of the paper is therefore to propose a displacement-based design methodology for the design of mixed RC-URM edifices and the retrofit of URM buildings by replacing or adding selected URM walls with RC ones. The article describes also two tools developed for estimating important quantities relevant for the displacement-based design of structures with both RC and URM walls. The tools are (i) a mechanical model based on the shear-flexure interaction between URM and RC walls and (ii) an elastic model for estimating the contribution of the RC slabs to the overturning moment capacity of the system. In the last part of the article the proposed design method is verified through nonlinear dynamic analyses of several case studies. These results show that the proposed design approach has the ability of controlling the displacement profile of the designed structures, avoiding concentration of deformations in one single storey, a typical feature of URM wall structures.

• 한국지진공학회논문집
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• 제22권5호
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• pp.261-269
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• 2018

This study examines earthquake-induced sloshing effects on liquid storage tanks using computation fluid dynamics. To achieve this goal, this study selects an existing square steel tank tested by Seismic Simulation Test Center at Pusan National University as a case study. The model validation was firstly performed through the comparison of shaking table test data and simulated results for the water tank subjected to a harmonic excitation. For a realistic estimation of the wall pressure response of the water tank, three recorded earthquakes with similar peak ground acceleration are applied:1940 El Centro earthquake, 2016 Gyeongju earthquake, and 2017 Pohang earthquake. Wall pressures monitored during the dynamic analyses are examined and compared for different earthquake motions and monitoring points, using power spectrum density. Finally, the maximum dynamic pressure for three earthquakes is compared with the design pressure calculated from a seismic design code. Results indicated that the maximum pressure from the El Centro earthquake exceeds the design pressure although its peak ground acceleration is less than 0.4 g, which is the design acceleration. On the other hand, the maximum pressure due to two Korean earthquakes does not reach the design pressure. Thus, engineers should not consider only the peak ground acceleration when determining the design pressure of water tanks.

• Earthquakes and Structures
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• 제9권6호
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• pp.1251-1272
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• 2015

It is widely recognized that the preferred yielding mechanism for a hybrid coupled wall structure is that all coupling beams over the height of the structure yield in shear prior to formation of plastic hinges in structural walls. The objective of the study is to provide feasible approaches that are able to promote the preferred seismic performance of hybrid coupled walls. A new design methodology is suggested for this purpose. The coupling ratio, which represents the contribution of coupling beams to the resistance of system overturning moment, is employed as a fundamental design parameter. A series of nonlinear time history analyses on various representative hybrid coupled walls are carried out to examine the adequacy of the design methodology. While the proposed design method is shown to be able to facilitate the desired yielding mechanism in hybrid coupled walls, it is also able to reduce the adverse effects caused by the current design guidelines on the structural design and performance. Furthermore, the analysis results reveal that the state-of-the-art coupled wall design guidelines could produce a coupled wall structure failing to adequately exhaust the energy dissipation capacity of coupling beams before walls yield.

• Advances in Computational Design
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• 제4권3호
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• pp.223-238
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• 2019

This study investigated the ultimate lateral load capacity of shear walls constructed with several types of structural foam sheathing. Sixteen tests were conducted and the results were compared to the published design values commutated by the manufactures for each test series. The sheathing products included 12.7 mm (1/2 in) SI-Strong, 25.4 mm (1 in) SI-Strong, 12.7 mm (1/2 in) R-Max Thermasheath, and 2 mm (0.078 in) ThermoPly Green. The structural foam sheathing was attached per the manufacturers' specification to one side of the wood frame for each wall tested. Standard 12.7 mm (1/2 in) gypsum wallboard was screwed to the opposite side of the frame. Simpson HDQ8 tie-down anchors were screwed to the terminal studs at each end of the wall and anchored to the base of the testing apparatus. Both monotonic and cyclic testing following ASTM E564 and ASTM E2126, respectively, were considered. Results from the monotonic tests showed an 11 to 27 percent smaller capacity when compared to the published design values. Likewise, the test results from the cyclic tests showed a 24 to 45 percent smaller capacity than the published design values and did not meet the seismic performance design criteria computation.