Structural Design of Mid-Story Isolated High-Rise Building - Roppongi Grand Tower

Nakamizo, Daiki,Koitabashi, Yuichi Council on Tall Building and Urban Habitat Korea 2018 International journal of high-rise buildings Vol.7 No.3

Since the response reduction effect on over 200-meter-tall resulting from the seismic isolation system is smaller in general than low-rise and mid-rise buildings, mid-story isolated buildings are considered to reduce the response in the upper part above the isolation story, however, in many cases, the acceleration response just below the isolation story is likely to be the largest. This paper presents the structural design schemes, the design of the main structural frames, and the constructions of a 230-meter-tall super high-rise building with mid-story isolation mechanism integrated in Roppongi, Tokyo. Moreover, this paper shows how the architectural and structural design for integrating a mid-story isolation system in a super high-rise building has been conducted and what solutions have been derived in this project. The realization of this building indicates new possibilities for mid-story isolation design for super high-rise buildings.

Hurricane vulnerability model for mid/high-rise residential buildings

Pita, Gonzalo L.,Pinelli, Jean-Paul,Gurley, Kurt,Weekes, Johann,Cocke, Steve,Hamid, Shahid Techno-Press 2016 Wind and Structures, An International Journal (WAS Vol.23 No.5

Catastrophe models appraise the natural risk of the built-infrastructure simulating the interaction of its exposure and vulnerability with a hazard. Because of unique configurations and reduced number, mid/high-rise buildings present singular challenges to the assessment of their damage vulnerability. This paper presents a novel approach to estimate the vulnerability of mid/high-rise buildings (MHB) which is used in the Florida Public Hurricane Loss Model, a catastrophe model developed for the state of Florida. The MHB vulnerability approach considers the wind pressure hazard exerted over the building's height as well as accompanying rain. The approach assesses separately the damages caused by wind, debris impact, and water intrusion on building models discretized into typical apartment units. Hurricane-induced water intrusion is predicted combining the estimates of impinging rain with breach and pre-existing building defect size estimates. Damage is aggregated apartment-by-apartment and story-by-story, and accounts for vertical water propagation. The approach enables the vulnerability modeling of regular and complex building geometries in the Florida exposure and elsewhere.

Hurricane vulnerability model for mid/high-rise residential buildings

Gonzalo L. Pita,Jean-Paul Pinelli,Kurt Gurley,Johann Weekes,Steve Cocke,Shahid Hamid 한국풍공학회 2016 Wind and Structures, An International Journal (WAS Vol.23 No.5

Catastrophe models appraise the natural risk of the built-infrastructure simulating the interaction of its exposure and vulnerability with a hazard. Because of unique configurations and reduced number, mid/high-rise buildings present singular challenges to the assessment of their damage vulnerability. This paper presents a novel approach to estimate the vulnerability of mid/high-rise buildings (MHB) which is used in the Florida Public Hurricane Loss Model, a catastrophe model developed for the state of Florida. The MHB vulnerability approach considers the wind pressure hazard exerted over the building's height as well as accompanying rain. The approach assesses separately the damages caused by wind, debris impact, and water intrusion on building models discretized into typical apartment units. Hurricane-induced water intrusion is predicted combining the estimates of impinging rain with breach and pre-existing building defect size estimates. Damage is aggregated apartment-by-apartment and story-by-story, and accounts for vertical water propagation. The approach enables the vulnerability modeling of regular and complex building geometries in the Florida exposure and elsewhere.

Structural Design and Performance Evaluation of a Mid-story Seismic Isolated High-Rise Building

Tamari, Masatoshi,Yoshihara, Tadashi,Miyashita, Masato,Ariyama, Nobuyuki,Nonoyama, Masataka Council on Tall Building and Urban Habitat Korea 2017 International journal of high-rise buildings Vol.6 No.3

This paper describes some of the challenges for structural design of a mid-story seismic isolated high-rise building, which is located near Tokyo station, completed in 2015. The building is a mixed-use complex and encompasses three volumes: one substructure including basement and lower floors, and a pair of seismic isolated superstructures on the substructure. One is a 136.5m high Main Tower (office use), and the other is a 98.5 m high South Tower (hotel use). The seismic isolation systems are arranged in the $3^{rd}$ floor of the Main Tower and $5^{th}$ floor of the South Tower, so that we call this isolation system as the mid-story seismic isolation. The primary goal of the structural design of this building was to secure high seismic safety against the largest earthquake expected in Tokyo. We adopted optimal seismic isolation equipment simulated by dynamic analysis to minimize building damage. On the other hand, wind-induced vibration of a seismic isolated high-rise building tends to be excited. To reduce the vibration, the following strategies were adopted respectively. In the Main Tower with a large wind receiving area, we adopted a mechanism that locks oil dampers at the isolation level during strong wind. In the South Tower, two tuned mass dampers (TMDs) are installed at the top of the building to control the vibration. In addition, our paper will also report the building performance evaluated for wind and seismic observation after completion of the building. In 2016, an earthquake of seismic intensity 3 (JMA scale) occurred twice in Tokyo. The acceleration reduction rate of the seismic isolation level due to these earthquakes was approximately 30 to 60%. These are also verified by dynamic analysis using observed acceleration data. Also, in April 2016, a strong wind exceeding the speed of 25m/s occurred in Tokyo. On the basis of the record at the strong wind, we confirmed that the locking mechanism of oil damper worked as designed.

중간층 면진시스템 설치 위치에 따른 고층건물의 지진응답 분석

김가영,이영락,김현수,강주원 한국공간구조학회 2017 한국공간구조학회지 Vol.17 No.4

Base isolation system is generally used for low-rise buildings. For high-rise buildings subjected to earthquake loads, a mid-story isolation system was proposed and applied to practical engineering. In this study, seismic responses of high-rise buildings considering the installation story of the mid-story isolation system were evaluated. To do this, the 20-story and 30-story building were used as example structures. Historical earthquakes such as Kobe (1995), Northridge (1994) and Loma Prieta (1989) earthquakes were employed applied as earthquake excitations. The installation location of the mid-story isolation system was changed from the bottom of the 1st floor to the bottom of the top floor. The seismic responses of the example building were investigated by changing the location of the isolation layer. Based on the analytical results, when the seismic isolation system is applied, story drift ratio and acceleration response are reduced compared to the case without the isolation system. When the isolation layer is located on the lower part of the building, it is most effective. However, in that case, the possibility that the structure is unstable increases. Therefore, an engineer should consider both structural efficiency and safety when a mid-story isolation system for a high-rise building is designed.

Effect of rapid screening parameters on seismic performance of RC buildings

Hayri B. Ozmen,Mehmet Inel 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.62 No.4

This study investigates the effects of soft story, short columns, heavy overhangs, pounding, and construction and workmanship quality parameters on seismic response of reinforced concrete buildings through nonlinear static and dynamic procedures. The accounted parameters are selected for their common use in rapid screening of RC buildings. The 4- and 7-story buildings designed according to pre-modern codes are used to reflect majority of the existing building stock. The relative penalty scores are employed in this study to evaluate relative importance of certain irregularities in the existing rapid seismic assessment procedures. Comparison of relative scores for the irregularities considered in this study show that the overall trend is similar. The relatively small differences may be accounted for regional construction practices. It is concluded that initial-phase seismic assessment procedures based on architectural features yield in somewhat similar results independent of their bases. However, the differences in the scores emphasize the proper selection of the method based on the regional structure characteristics.

Evaluation of the influence of creep and shrinkage determinants on column shortening in mid-rise buildings

B-Jahromi, Ali,Rotimi, Abdulazeez,Tovi, Shivan,Goodchild, Charles,Rizzuto, Joseph Techno-Press 2017 Advances in concrete construction Vol.5 No.2

The phenomenon of concrete column shortening has been widely acknowledged since it first became apparent in the 1960s. Axial column shortening is due to the combined effect of elastic and inelastic deformations, shrinkage and creep. This study aims to investigate the effects of ambient temperature, relative humidity, cement hardening speed and aggregate type on concrete column shortening. The investigation was conducted using a column shortening prediction model which is underpinned by the Eurocode 2. Critical analysis and evaluation of the results showed that the concrete aggregate types used in the concrete have significant impact on column shortening. Generally, aggregates with higher moduli of elasticity hold the best results in terms of shortening. Cement type used is another significant factor, as using slow hardening cement gives better results compared to rapid hardening cement. This study also showed that environmental factors, namely, ambient temperature and relative humidity have less impact on column shortening.

중층건물의 풍직각방향 풍하중 산정

정승용,강현구 한국풍공학회 2019 한국풍공학회지 Vol.23 No.4

The current Korean building code (KBC 2016) presents across-wind load of building with aspect ratio less than 3 by multiplying a coefficient to along-wind load. However, the vertical distributions of along- and across-wind are different. They may also be different due to different power spectral density functions when a building is flexible enough to consider resonant component. Thus, in this study, across-wind loads of mid-rise buildings with aspect ratio from 1 to 3 obtained from wind tunnel tests by Tokyo Polytechnic University are compared with those based on KBC 2016. Finally, based on the comprehensive comparison, new equations for determination of across-wind load on mid-rise buildings are proposed. 현재 건축구조기준(KBC 2016)에서는 형상비 3이하의 건물의 풍직각방향 풍하중을 풍방향 풍하중에 계수를 곱하여 약산식으로 산정하고 있다. 하지만 풍직각방향 풍하중 수직분포 형태가 풍방향 풍하중과 다르며, 형상비가 3이하이지만 유연구조물에 속해 공진 성분을 고려해야 되는 경우 풍방향 풍하중과 다른 파워스펙트럼 밀도 함수로 인해 차이가 발생할 수 있다. 따라서 이 연구에서는 Tokyo Polytechnic University에서 제공하는 풍동실험 데이터베이스로부터 형상비 1에서 3사이 중층건물에 작용하는 풍직각방향 풍하중을 KBC 2016과 비교하였고, 이에 기반하여 중층건물의 풍직각방향 풍하중 산정식을 제시하였다.

Soil-structure interaction vs Site effect for seismic design of tall buildings on soft soil

Fatahi, Behzad,Tabatabaiefar, S. Hamid Reza,Samali, Bijan Techno-Press 2014 Geomechanics & engineering Vol.6 No.3

In this study, in order to evaluate adequacy of considering local site effect, excluding soil-structure interaction (SSI) effects in inelastic dynamic analysis and design of mid-rise moment resisting building frames, three structural models including 5, 10, and 15 storey buildings are simulated in conjunction with two soil types with the shear wave velocities less than 600 m/s, representing soil classes $D_e$ and $E_e$ according to the classification of AS1170.4-2007 (Earthquake actions in Australia) having 30 m bedrock depth. Structural sections of the selected frames were designed according to AS3600:2009 (Australian Standard for Concrete Structures) after undertaking inelastic dynamic analysis under the influence of four different earthquake ground motions. Then the above mentioned frames were analysed under three different boundary conditions: (i) fixed base under direct influence of earthquake records; (ii) fixed base considering local site effect modifying the earthquake record only; and (iii) flexible-base (considering full soil-structure interaction). The results of the analyses in terms of base shears and structural drifts for the above mentioned boundary conditions are compared and discussed. It is concluded that the conventional inelastic design procedure by only including the local site effect excluding SSI cannot adequately guarantee the structural safety for mid-rise moment resisting buildings higher than 5 storeys resting on soft soil deposits.

중층 모듈러 건축물을 위한 PC 코어의 수평접합부에 대한 탄성연결 요소를 이용한 모델링 기법

이상섭 대한건축학회 2023 대한건축학회논문집 Vol.39 No.11

This study presents an approach to model the horizontal connections of precast concrete (PC) panels as elastic link elements, utilizing PCcores as the lateral force-resisting system for a 15-story modular building. While in situ concrete (RC) cores are commonly used for lateralforce resistance in mid- to high-rise modular buildings, the substantial onsite work requirements can reduce construction efficiency. To tacklethis issue, there is ongoing research on using PC cores as an alternative solution, with instances of commercial use observed abroad. PC corecomponents include 3D boxes and 2D panels, with limited use of 3D boxes due to their weight. When forming a core shear wall with 2DPC panels, both horizontal and vertical connections are typically needed for proper design. Unlike RC cores, PC cores lack a continuousconcrete structure, resulting in reduced stiffness. To represent this stiffness reduction in commercial analysis programs, a reference stiffnesssimulating the behavior of monolithic walls has been established. This study also examined the seismic and wind performance of the 15-storymodular building in light of stiffness reduction. 이 연구는 15층 모듈러 건축물의 횡력저항시스템으로 프리캐스트 콘크리트(PC) 코어를 적용하기 위해 PC 패널의 수평접합부를 탄성 연결 요소로 모델링하는 것에 관한 것이다. 중고층 모듈러 건축물의 횡력정하시스템으로 현장타설 콘크리트(RC) 코어가 널리 적용되고 있지만 상당한 현장 작업이 필요하여 건설 생산성을 저하시킨다. 이를 개선하기 위한 방안으로 PC 코어가 연구되고 있으며, 국외에서는 제품화된 사례도 찾아볼 수 있다. PC 코어에 사용되는 부재는 3D 박스 또는 2D 패널이 있으며, 3D 박스는 무거운 무게로 인해 사용이 제한적이다. 일반적으로 2D PC 패널로 코어의 전단벽을 형성하는 경우 수평접합과 수직접합이 필요하며, 올바른 설계를 위해 해석 모델에 접합부의 거동을 반영하는 것이 바람직하다. PC 코어는 RC 코어와 다르게 연속적인 콘크리트 구조가 될 수 없기 때문에 강성이 떨어질 수밖에 없다. 이러한 강성 저하를 상용 해석프로그램에서 탄성 연결 요소로 모델링하기 위해 일체식 벽체의 거동을 모사할 수 있는 기준 강성을 찾았고, 강성 저하에 변수로 15층 모듈러 건축물의 내진성능과 내풍성능을 검토하였다.