In apartment buildings in Korea, irregular walls, such as T-, L-, and U-shaped walls, are commonly used. However, in practical design, the geometric irregularities of walls are often neglected when determining the length of the lateral confinement region. Further, although earthquake loads apply from various directions, the lateral confinement region is typically determined for the in-plane direction of the web. Thus, using finite element analysis, this study investigated the structural performance of irregular walls subjected to various loading directions. As the design parameters, wall shape, cross-sectional aspect ratio, and loading direction were addressed. According to the parametric analysis results, as the length of flange in tension increased, the lateral confinement region should be evaluated with consideration of the geometric irregularity. Further, for the L- and U-shaped walls, it is recommended to evaluate the lateral confinement region for various loading directions. Based on these results, a design method to determine the lateral confinement region of irregular walls was suggested.
Currently, the demand for high-rise buildings is increasing worldwide, and this trend is also appearing in Korea. Buildings have different planar and elevation shapes, and as a result, buildings with different shapes are constructed. In this study, 122 buildings over 150m, which are scheduled to be completed and completed in Korea, were selected as the subjects of the study to analyze the correlation between the planar shape and the elevation shape of domestic buildings and to understand the current status. As a result of the analysis, in the case of current high-rise buildings in Korea, the application of Overlapping elements and Prismatic elements was high in the elevation shape, and there were many rectangular and polygonal planes in the plane shape. It is judged that the shape distribution of high-rise buildings in Korea can be grasped by analyzing the correlation between these two shape factors.
본 연구에서는 구조물의 응답 데이터를 기반으로 고유진동수, 감쇠비 등 동특성과 풍하중 모델의 파라미터를 동시에 추정할 수 있는 스펙트럼 백색화 기반 식별 기법을 제안하고, 이를 실제 40층 고층 구조물에 적용하여 실용성과 정확도를 평가하였다. 기존 연 구에서는 본 기법을 수치 시뮬레이션 및 풍동 실험에 적용하여 그 타당성을 입증한 바 있으나, 실계측 응답 데이터를 활용한 실구조물 적용에 대해서는 검증이 이루어지지 않았다. 본 연구는 이를 확장하여, 장기간 계측된 고층 건축물의 진동 응답을 분석하고, 각 주요 모드에 대해 백색화 처리를 수행함으로써 구조물 전달함수 및 풍하중 전달함수의 파라미터를 최적화 기반으로 동시 추정하였다. 특히 백색 잡음의 누적 파워 스펙트럼 길이를 목적함수로 설정함으로써, 기존 커브 피팅 기반 기법 대비 감쇠비 추정의 정확도와 안정성을 향상시켰다. 분석 결과는 전통적인 모달 식별 기법(예: SSI)과의 비교를 통해 제안 기법의 유효성을 입증하였으며, 풍하중 모델 파라미 터까지 포함하는 통합적 구조 해석 프레임워크로서의 가능성을 제시하였다. 본 연구는 향후 구조물의 풍응답 예측, 하중 생성 모델 구 축, 구조 건전도모니터링(SHM) 및 디지털 트윈 기반 해석 등 다양한 실무 응용에 기여할 수 있을 것으로 기대된다.
Apartments such as those on the 29th floor are generally classified as high-rise buildings; however, they may be excluded from certain safety regulations since they do not meet the legal definition of "high-rise" buildings. According to the Korean Building Act, buildings with 30 or more floors are typically regarded as high-rise buildings, warranting specific disaster prevention and safety standards. Nevertheless, buildings between 20 and 30 floors are often excluded from high-rise building regulations, which may lead to relatively insufficient safety standards and has been identified as a "blind spot in safety management." Enhancing appropriate safety facilities and strengthening regulations for such buildings is crucial, particularly in areas such as fire prevention, evacuation planning, and fire-fighting facilities. This study compares and examines the evacuation times of designated evacuation safety zones and emergency elevators in high-rise apartments as defined by the Building Act and in buildings constructed with floors between 20 and 30 through evacuation simulations.
The diagrid structural system has a braced frame that simultaneously resists lateral and vertical loads, and is being applied to many atypical high-rise buildings for aesthetic effects. In this study, a 60-story structure with twisted degrees of 0° to 180° was selected to determine seismic response control performance of twisted high-rise structures whether the diagrid system was applied and according to the reduction of braced frame material quantity. For this purpose, ‘Nor’ model without the diagrid system and the ‘DS’ model with the diagrid system, which was modeled by reducing braced frame member section to 700~400, were modeled. As a result, the 'DS' model showed an seismic response control effect in all Twisted models even when the quantity was reduced, and especially, the Twisted shape model was found to have an superior response control effect compared to the regular structure. In addition, the ‘600DS’ analysis model, which matched the ‘Nor’ model by 99.0% in quantity, showed an increase in seismic response control performance as the rotation angle increased.
Recently, high-rise residential buildings in Korea have adopted slender shear walls with irregular section shapes, such as T-shape, H-shape, and C-shape. In the seismic design of the slender shear walls, the transverse reinforcement for lateral confinement should be provided in the boundary elements to increase deformation capacity and subsequent ductility. However, in practice, the irregularity of the shear walls is not adequately considered, and the lateral confinement region is calculated for the rectangular wall segments. This study investigated the proper design method for lateral confinement regions using finite element analysis. The lateral confinement region was considered in analysis for two cases: 1) as a typical rectangular wall segment and 2) as an irregular wall. When the irregularity of the walls was considered, the compression zone depth was increased because the vertical reinforcement in the flange was addressed. The effect of lateral confinement design methods on the structural performance of the walls was directly compared under various design parameters, including the length of the flange, concrete compressive strength, vertical rebar layout, axial load ratio, and loading direction. According to the results of the parametric analysis, the peak strength and deformation capacity could be significantly increased when the lateral confinement region was calculated based on irregularly shaped walls, regardless of the design parameters. In addition, the effective compression zone was located within the lateral confinement region. Thus, it is recommended that the lateral confinement region of T-shaped walls is calculated by addressing the irregularity of the walls.
Since atypical high-rise buildings are vulnerable to gravity loads and seismic loads, various structural systems must be applied to ensure the stability of the structure. In this study, the authors selected a 60-story twisted-shaped structure among atypical high-rise structures as an analytical model to investigate its structural behavior concerning the outrigger system. The structural analyses were performed varying the number of installed layers and the arrangement of the outrigger system, as well as the placement of the mega column, as design variables. The analysis revealed that the most effective position for the outrigger was 0.455H from the top layer, consistent with previous studies. Additionally, connecting outriggers and mega columns significantly reduced the displacement response of the model. From an economic standpoint, it is deemed efficient to connect and install outriggers and mega columns at the structure's ends.
Recently, in newly constructed apartment buildings, the exterior wall structures have been characterized by thinness, having various openings, and a significantly low reinforcement ratio. In this study, a nonlinear finite element analysis was performed to investigate the crack damage characteristics of the exterior wall structure. The limited analysis models for a 10-story exterior wall were constructed based on the prototype apartment building, and nonlinear static analysis (push-over analysis) was performed. Based on the finite element (FE) analysis model, the parametric study was conducted to investigate the effects of various design parameters on the strength and crack width of the exterior walls. As the parameters, the vertical reinforcement ratio and horizontal reinforcement ratio of the wall, as well as the uniformly distributed longitudinal reinforcement ratio and shear reinforcement ratio of the connection beam, were addressed. The analysis results showed that the strength and deformation capacity of the prototype exterior walls were limited by the failure of the connection beam prior to the flexural yielding of the walls. Thus, the increase of wall reinforcement limitedly affected the failure modes, peak strengths, and crack damages. On the other hand, when the reinforcement ratio of the connection beams was increased, the peak strength was increased due to the increase in the load-carrying capacity of the connection beams. Further, the crack damage index decreased as the reinforcement ratio of the connection beam increased. In particular, it was more effective to increase the uniformly distributed longitudinal reinforcement ratio in the connection beams to decrease the crack damage of the coupling beams, regardless of the type of the prototype exterior walls.
본 연구에서는 델파이 조사를 통한 초고층건물 빌딩풍 관련 법·제도의 개선방안을 제시하였다. 법·제도의 개선방안을 제시하 기 위하여 언론보도 및 소셜 미디어(social media) 등을 기초로 초고층건물 빌딩풍 관련 사회적 이슈를 조사하여 초고층건물 빌딩풍 관 련 법·제도 정책제안을 도출하였다. 도출된 정책제안은 관련 법·제도의 현황 및 문제점을 분석하여 이를 개선할 수 있는 정책을 제언 하였으며, 해당 정책제언의 적합성을 평가하기 위하여 10인의 초고층건물 빌딩풍 관련 재난 전문가를 대상으로 델파이 조사를 실시하 였다. 전체 중 70% 이상이 해당 정책제안이 적합하다고 평가되었으며, 추가적으로 각각의 정책제안에 대한 중요도를 평가하였다. 본 연구에서 분석한 초고층건물 빌딩풍 관련 법·제도 개선방안은 향후 발생할 수 있는 초고층건물 빌딩풍 재난에 대한 피해 예방을 위하 여 활용될 수 있다.
Recently, the construction of tall buildings utilized by high strength-concrete in the whole world is tending to be on the rise. The application of high-rise structural system in buildings results in the excellent cut-down effect in construction materials due to section reduction. Therefore, in order to investigate the CO2 and resource reduction effect for the high-rise structural system, comparisons of GWP and ADP in embodied energy of structural materlais between 4 type of high-rise structural system have been performed. As a result, GWP emission increased in the order of steel structure outrigger system, RC shear wall system, and RC outrigger system. On the other hand, ADP emissions increased in the order of RC shear wall system, RC outrigger system, and steel structure outrigger system.
초고층 건물에서 수평변위 제어와 수직부재에서 발생하는 부등축소에 대한 검토가 필수적이다. 이러한 부등축소는 비구조요소의 사용성과 구조요소의 안전성에 대해 문제를 야기할 수 있다. 따라서 이 연구에서는 120층 규모의 철근콘크리트 주거용 초고층 건물에 대해 시공단계해석을 수행하여 각 수직부재의 부등축소량을 비교하고 콘크리트의 장기거동의 영향을 분석하였다. 이를 위해 영향요 인에 따라 축소량을 탄성축소량, 크리프축소량, 건조수축축소량으로 구분하여 검토하였으며 최대 절대축소량에 대한 지배적 요인을 분석하였다. 또한, 입주완료 후 30년에서 발생한 부등축소량에 대해 사용성 검토를 진행하였으며, 구조요소에 대해 설계단계와 시공 단계의 부재력을 비교하여 분석하였다.
Currently, the construction trend of high-rise structures is changing from a cube-shaped box to a free-form. In the case of free-form structures, it is difficult to predict the behavior of the structure because it induces torsional deformation due to inclined columns and the eccentricity of the structure by the horizontal load. For this reason, it is essential to review the stability by considering the design variables at the design stage. In this paper, the position of the weak vertical member was analyzed by analyzing the behavior of the structure according to the change in the core position of the twisted high-rise structures. In the case of the shear wall, the shear force was found to be high in the order of proximity to the center of gravity of each floor of the structure. In the case of the column, the component force was generated by the axial force of the outermost beam, so the bending moment was concentrated on the inner column with no inclination.
초고층 건물에서 수평변위 제어와 수직부재에서 발생하는 부등축소에 대한 검토가 필수적이다. 수평변위 제어를 위해 근래에 아웃 리거 구조시스템과 메가 구조시스템을 횡력저항시스템으로 사용한 초고층 건물이 증가하고 있다. 또한, 부등축소로 인한 구조적 문 제를 해결하기 위해 부등축소량 예측과 예측결과를 통한 시공단계에서의 보정방법이 연구되어 왔으나 부등축소에 대한 횡력저항시 스템의 영향 비교는 드문 편이다. 따라서, 본 논문에서는 수평변위 제어를 위해 아웃리거 구조시스템과 메가 구조시스템을 사용한 60 층 규모의 철근콘크리트 주거용 초고층 건물에 대해 시공단계해석을 통한 부등축소를 비교하고 그 영향을 분석하고자 한다. 또한, 부 등축소는 비구조요소의 파손 및 구조요소에 부가하중을 유발하기도 하며 부등축소가 야기한 문제는 초고층 건물에서 중요한 부재를 손상시킬 수 있으므로 각 횡력저항시스템별로 수직부재의 부등축소에 대한 영향을 분석하였다.
한반도 남해안 지역의 여름철 대기 안정도 특성을 분석함으로써, 한반도 특성에 맞는 강수 예측을 위한 대기 안정도 지수의 정량적인 임계값을 도출하고자 하였다. 보성 표준기상관측소에서 관측한 2019년도 여름철 라디오존데 집중관측자료를 분석에 사용하였으며, 총 관측자료는 243개이다. 강수 유무 및 중규모 대기 현상에 대한 대기 안정도를 분석하기 위해서, 대류가용잠재에너지(Convective Available Potential Energy, CAPE)와 폭풍지수(Storm Relative Helicity, SRH)를 비교하였으며 특히 SRH 분석은 고도별로 총 4개의 층으로(0-1, 0-3, 0-6, 0-10 km) 세분화하였다. 강수 유무에 따른 분석은 강수가 없는 경우, 강수발생 전 12시간, 강수 발생 시로 구분하여 수행하였다. 그 결과, 2019년도 보성에서 발생한 여름철 강수 예측에는 CAPE 보다 SRH가 더 적합하며 0-6 km SRH가 약한 토네이도가 발생 가능한 기준과 같은 150 m 2 s−2 이상일 경우 강수가 발생한 것으로 분석 된다. 또한, 장마와 태풍 기간의 대기 안정도를 분석한 결과를 보면, 일반적으로 SRH는 대기 깊이가 두꺼워질수록 값이 커지는데 반해서 0-10 km SRH 평균값 보다 0-6 km 의 SRH 값이 더 크게 나타났다. 따라서, 2019년도 보성에서 발생한 태풍에 의한 강수를 판별하는 데는 0-6 km 의 SRH 값이 더 효과적이라고 할 수 있다.
이 연구에서는 철근콘크리트 고층건물의 사례연구를 통해 성능기반 내풍설계를 수행하였고 그 적용성을 평가하였다. 초기 설계 시 비탄성 거동 도입을 위해 공진성분을 절반으로 줄여 설계하고, 이에 대한 비탄성 성능을 검증하였다. 비탄성 해석을 위한 해석 모델링 방법을 제시하고, 잦은 설계 변경에서도 적용할 수 있도록 시간이력 풍하중은 설계기준에서 제시하는 파워스펙트럼밀도 함수로부터 재생하였다. 이 때 비선형 해석을 위한 시간이력 하중 재생 시 고려해야 할 사항들을 함께 제시하였다. 해석 결과 공진성분을 줄여 설계했음에도 비탄성 거동은 수평부재에서만 발생하였고, 소성회전각은 즉시거주 성능 수준을 충족하였다.