• Computers and Concrete
• /
• 제16권1호
• /
• pp.141-161
• /
• 2015

A significant portion of residential areas of Turkey is located in active earthquake zones. In Turkey occurred major earthquakes in last twenty years, such as Erzincan (1992), Kocaeli and $D{\ddot{u}}zce$ (1999), $Bing{\ddot{o}}l$ (2003), Van (2011). These earthquakes have demonstrated that reinforced concrete (RC) buildings having horizontal and vertical irregularities are significantly damaged, which in turn most of them are collapsed. Architectural design and arrangement of load-bearing system have important effect on RC building since architectural design criteria in design process provide opportunity to make this type of buildings safer and economical under earthquake loads. This study aims to investigate comparatively the effects of weak story irregularity on earthquake behavior and rough construction costs of RC buildings by considering different soil-conditions given in the Turkish Earthquake Code. With this aim, Sta4-CAD program based on matrix displacement method is utilized. Considering that different story height and compressive strength of concrete, and infill walls or their locations are the variables, a set of structural models are developed to determine the effect of them on earthquake behavior and rough construction costs of RC buildings. In conclusion, some recommendations and results related to making RC buildings safer and more economical are presented by comparing results obtained from structural analyses.

• 한국주거학회:학술대회논문집
• /
• 한국주거학회 2005년도 추계학술대회 논문집
• /
• pp.223-228
• /
• 2005

This study examined and analyzed locational conditions of apartment houses in regional small cities to provide basic materials to set direction and index of view management of apartment house and thus the results of the study are as follows. 1. The number of story of apartment houses 'below five story' was 48% and area of apartment house was 'over 500m$^2$ and below 1000m$^2$' in 31% of the whole regions. 2. As a result of analyzing correlations with changes of floor of apartment house by construction year, apartment houses below 10 story were mainly built between 1991 and 1995 and high-storied apartment houses over 11 story were mainly built since 1995 and apartment houses over 21 story were built since 2000 and these high-storied apartment houses were main cause of hindering view of small cities. Accordingly, establishment of guideline of building high-storied apartment house which can be a primary obstacle of urban view and regulations of height are needed.

• Steel and Composite Structures
• /
• 제37권6호
• /
• pp.679-693
• /
• 2020

This paper investigates the seismic response of buildings equipped with Self-Centering Energy Dissipating (SCED) braces. Two-dimensional models of 3, 6, 12 and 16-story SCED buildings considering both material and geometric nonlinearities are investigated by carrying out pushover and nonlinear time-history analyses. The response indicators of the buildings are studied for weight-scaled ground motions to represent the Design Basis Earthquake (DBE) level and the Maximum Considered Earthquake (MCE) event. The fragility curves of the buildings for two Immediate Occupancy (IO) and Life Safety (LS) performance levels are developed using Incremental Dynamic Analysis (IDA). Results of the nonlinear response history analyses indicate that the maximum inter-story drift occurs at the taller buildings. The mean peak inter-story drift is less than 2% in both hazard levels. High floor acceleration peaks are observed in all the SCED frames regardless of the building height. The overall ductility and ductility demand increase when the number of stories reduces. The results also showed the residual displacement is negligible for all of case study buildings. The 3 and 6-story buildings exhibit desirable performance in IO and LS performance levels according to fragility curves results, while 12 and 16-story frames show poor performance especially in IO level. The results indicated the SCED braces performance is generally better in lower-rise buildings.

• 한국안전학회지
• /
• 제30권6호
• /
• pp.94-101
• /
• 2015

When a severe disaster such as a building collapse occurs, a first priority for rapid rescue is to find a location where people are highly expected to be buried but alive. It is, however, very difficult to correctly designate the location of such cavities by conventional geophysical survey due to a pile of debris of building members. In this study, location of possible lifeguard cavities were evaluated through a series of simulations of building collapse by explosion depending on the height of the building, a structure of basement floor and a location of explosion. Three types of building structure: five-story, ten-story and fifteen-story were prepared as a model for the simulation. As a results, in the case of low building, only basement floor partially collapsed. On the other hand, in the case of high building, a collapsed range on the inside of the building increased and lifeguard spaces were formed only in the lateral side or corner of the building. In addition, when a wall exists in the basement floor, the possibility that cavities could be formed increased compared to the cases without wall. However, for the fifteen-story building case, no possible lifeguard cavity was found. It is noted that for a high rise building, the height of building more affect forming of safeguard cavity than the structure of the basement floor.

• 한국구조물진단유지관리공학회 논문집
• /
• 제9권1호
• /
• pp.171-180
• /
• 2005

본 연구에서는 기름이나 가스의 송유관을 지지하기 위하여 일반적으로 사용되는 3층의 Knee brace가 설치된 모멘트저항골조(KBMRF)의 내진성능을 평가하였다. KBMRF의 하중-변위 관계를 관찰하기 위하여 비선형 정적 pushover 해석을 수행하였다. 최대층간변위가 층높이의 1.5%에 도달하였을 때 보와 기둥과 같은 주요 구조부재는 탄성상태를 유지하는 것으로 나타났다. UBC-97의 설계스펙트럼에 부합되도록 조정한 8개의 지진기록을 이용하여 비선형 동적시간이력해석을 수행한 결과에 따르면, 최대층간변위는 구조물 높이의 1.5% 변위한계보다 작았고 기둥은 탄성적으로 거동하였다. 따라서 본 연구에서 고려한 KBMRF 구조물의 내진성능은 내진설계기준에서 규정한 모든 요구사항을 만족하는 것으로 나타났다.

• 한국지진공학회논문집
• /
• 제7권2호
• /
• pp.29-37
• /
• 2003

본 연구에서는 지진하중에 의하여 철골 모멘트저항골조(MRF)와 좌굴이 방지된 가새골조(BRBF) 그리고 힌지로 접합된 좌굴이 방지된 가새골조(HBRBF)에서 발생하는 층별 이력에너지의 분포에 대하여 고찰하였다. 예제 구조물의 에너지 요구량을 산정하기 위하여 다른 지반조건에서 계측된 60개의 지진기록을 사용하였다. 해석결과에 따르면 MRF와 BRBF에서의 이력에너지는 밑면에서 최대가 되고 상부층으로 갈수록 점진적으로 감소하여, 상부층에서는 부재의 이력거동이 거의 발생하지 않았다. 그러나 HBRBF에서의 층별 이력에너지는 구조물의 높이에 따라 상대적으로 균등하게 분포하였으며, 이러한 경우 손상이 한 층에 집중적으로 발생하지 않아 다른 시스템에 비하여 보다 바람직하다고 할 수 있다. 연암 지반, 연약한 토사, 단층 근처의 지반 조건에 따른 에너지의 분포형태는 거의 동일하게 나타났다.

• Structural Engineering and Mechanics
• /
• 제46권3호
• /
• pp.337-352
• /
• 2013

Seismic performance of critical facilities has been focused on the structural components over the past decade. However, most earthquake damages were observed to the nonstructural components during and after the earthquakes. The primary objective of this research was to develop the seismic fragility of the piping system incorporating the nonlinear Tee-joint finite element model in the full scale piping configuration installed in critical facilities. The procedure for evaluating fragility curves corresponding to the first damage state was considered the effects of the top floor acceleration sensitivities for 5, 10, 15, and 20 story linear RC and steel building systems subjected to 22 selected ground motions as a function of ground motion uncertainties. The result of this study revealed that the conditional probability of failure of the piping system on the top floor in critical facilities did not increase with increased level of story height and in fact, story level in buildings can tune the fragilities between the building and the piping system.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2006년도 정기 학술대회 논문집
• /
• pp.733-740
• /
• 2006

Inverted V (or chevron) braced steel frames have been seen as being highly prone to soft story response once the compression brace buckles under earthquake loading. To salvage chevron braced frames. the concept of the zipper column was proposed many years ago such that the zipper column can redistribute the inelastic demand over the height of the building. However. rational design method for the zipper column has not been established yet. In this paper, a new dynamic design method for the zipper column was proposed by combining the refined physical braced model and modal pushover analysis. Inelastic dynamic analysis conducted on 6 story building model showed that the proposed method was more superior to the existing static design method and was very effective in improving seismic performance of chevron braced steel frames.

• 한국지진공학회논문집
• /
• 제22권5호
• /
• pp.299-309
• /
• 2018

Now that problems with force-based seismic design have been clearly identified, design is inclined toward displacement-based methods. One such widely used method is Direct-Displacement-Based Design (DDBD). Yet, one of the shortcomings of DDBD is considering higher-mode amplification of story shear, moments, and displacements using equations obtained from limited parametric studies of regular planar frames. In this paper, a different approach to account for higher-mode effects is proposed. This approach determines the lateral secant stiffness of the building frames that fulfill the allowable inter-story drift without exceeding the desired story displacements. Using the stiffness, an elastic response spectrum analysis is carried out to determine elastic higher-mode force effects. These force effects are then combined with DDBD-obtained first-mode force effects using the appropriate modal superposition method so that design can be performed. The proposed design procedure is verified using Nonlinear Time History Analysis (NTHA) of twelve planar frames in four categories accounting for mass and stiffness irregularity along the height. In general, the NTHA response outputs compared well with the allowable limits of the performance objective. Thus, it fulfills the aim of minimizing the use of NTHA for planar frame buildings, thereby saving computational resources and effort.

• 한국전통조경학회지
• /
• 제28권3호
• /
• pp.98-104
• /
• 2010

본 논문의 목적은 삼첩석, 이첩석 및 돌탑으로 이루어져 있는 '안동 서지리 성황당'을 사례로 하여 당산숲의 구성요소인 돌탑의 조형 양식에 대한 유래와 특징을 고찰한 것이다. 세개의 돌탑은 옛당산숲으로 보이는 마을 안쪽의 개천변 소나무 동산 정상에 있다. 세 돌은 일직선상으로 9m 거리에 걸쳐 위치하고 있으며 마을을 바라보며 왼쪽에 삼첩석, 가운데에 이첩석, 오른쪽에 돌탑이 있다. 삼첩석의 제일 아래 쪽은 길이 2.5m, 폭 1.8m, 높이 1.3m이고, 이첩석의 아래 자연석은 길이 1.3m, 폭 1.5m, 높이 0.9m이다. 돌탑은 지름 3m의 원추형에 높이 1.8m로서 작은 돌을 쌓은 것인데, 일명 '모관석'은 현재 이첩석의 맨 위에 있던 것이 떨어져 나간 것으로서, 현재의 이첩석은 원래 삼첩석이었던 것으로 추정되며 그 까닭은 우리나라 고대 조형 방식의 원리인 삼재사상(三才思想)에 비추어 볼 때, 짝수로 이루어진 조형물은 예를 찾아볼 수 없기 때문이다. '안동 서지리 성황당'이 청동기시대의 거석문화와 후대의 민간신앙이 이어져 오는 과정을 보여 주는 예가 되는 것과 같이, 시기적으로 볼 때 돌탑은 청동기시대의 거대석인 왼쪽의 삼첩석을 기원으로 하고, 가운데에 위치한 좀 더 작은 크기의 삼첩석(현재는 이첩석)을 거쳐, 후대에 오른편에 있는 작은 크기의 보통 돌탑으로 그 조형 양식이 변화되어온 것으로 추정된다. '안동 서지리 성황당'은 돌탑의 기원이 청동기시대까지 거슬러 올라간다는 것을 보여주고 있는 귀중한 유적이라고 할 수 있다.