• Title/Summary/Keyword: Roof Frame

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A Test on the Aseismic Capacity of a Traditional Three-bay-straw-roof House(I) : Rock Site Condition (전통 초가삼간 가옥의 내진성능 평가 실험(I) : 암반지반 조건)

  • 서정문;최인길;전영선;이종림;신재철
    • Journal of the Earthquake Engineering Society of Korea
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    • v.1 no.4
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    • pp.11-20
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    • 1997
  • The aseismic capacity of a traditional three-bay-straw-roof wooden house for rock site condition is quantitatively estimated. One 1/4 scale model was tested for the Nahanni Earthquake with peak ground accelerations from 0.1g to 0.6g. The natural frequency of the wooden house in elastic range is 1.66 Hz and 2.15 Hz in longitudinal and transversal direction, respectively. Damping ratio of the house in elastic range is 7%. The horizontal acceleration response of the house is significantly reduced compared with the input motion due to the nonlinear inelastic characteristics of the Sagae-machum joint of the frame. The traditional wooden house has high aseismic capacity in the rock site condition where high frequency contents of motion are predominant.

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Seismic Performance Assessment of Roof-Level Joints with Steel Fiber-Reinforced High-Strength Concrete (강섬유보강 고강도콘크리트를 적용한 최상층 접합부의 내진성능 평가)

  • Kim, Sang-Hee;Kwon, Byung-Un;Kang, Thomas H.-K.
    • Journal of the Korea Concrete Institute
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    • v.28 no.2
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    • pp.235-244
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    • 2016
  • This study was conducted to verify seismic performance of special moment frame's joints at roof-level with high-strength concrete and SD600 bars. K-RC-H was designed according to the seismic code and K-HPFRC-H had 150% of the original hoop spacing and 1.0% steel fiber volume fraction compared with K-RC-H. Both specimens had remarkable seismic performance without noticeable decrease in moment, but with very good energy dissipation before rebar failure. The U-bars in the joint sufficiently constrained rebar's action that pushed the cover upward. SD600 bars with $1.25l_{dt}$ had minimum slip in the joint. It was considered that the steel fiber contributed to improvement of the bending moment and joint shear distortion, and the result showed that it would be possible to increase the hoop spacing to 150% of the regular spacing.

Assessment of ASCE 7-10 for wind effects on low-rise wood frame buildings with database-assisted design methodology

  • He, Jing;Pan, Fang;Cai, C.S.
    • Wind and Structures
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    • v.27 no.3
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    • pp.163-173
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    • 2018
  • The design wind pressure for low-rise buildings in the ASCE 7-10 is defined by procedures that are categorized into the Main Wind Force-Resisting System (MWFRS) and the Components and Cladding (C&C). Some of these procedures were originally developed based on steel portal frames of industrial buildings, while the residential structures are a completely different structural system, most of which are designed as low-rise light-frame wood constructions. The purpose of this study is to discuss the rationality (or irrationality) of the extension of the wind loads calculated by the ASCE 7-10 to the light-frame wood residential buildings that represent the most vulnerable structures under extreme wind conditions. To serve this purpose, the same approach as used in the development of Chapter 28 of the ASCE 7-10 that envelops peak responses is adopted in the present study. Database-assisted design (DAD) methodology is used by applying the dynamic wind loads from Louisiana State University (LSU) database on a typical residential building model to assess the applicability of the standard by comparing the induced responses. Rather than the postulated critical member demands on the industrial building such as the bending moments at the knee, the maximum values at the critical points for wood frame buildings under wind loads are used as indicators for the comparison. Then, the critical members are identified through these indicators in terms of the displacement or the uplift force at connections and roof envelope. As a result, some situations for each of the ASCE 7 procedures yielding unconservative wind loads on the typical low-rise residential building are identified.

Planning Method of Roof Framing through Inner Building of Changgyeonggung in 19th Century (19세기 창경궁(昌慶宮) 내전(內殿) 전각(殿閣)의 지붕가구(架構) 계획기법(計劃技法)에 관한 연구(硏究))

  • Kim, Ki Deoka;Han, Wook;Kim, Derk Moon
    • Korean Journal of Heritage: History & Science
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    • v.42 no.2
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    • pp.134-153
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    • 2009
  • This study is to examine closely the frame structure of buildings in the royal palace of Josen dynasty, focused on inner buildings of Changgyeonggung(昌慶宮) which is built in 19th century, through considering the member size of main structure and analyzing the slope of a rafter. The plans of a size on main member are as follows ; firstly, a length of the perimeter column was accorded with Gunggwolji(宮闕誌) and the planning size of interior column was shown to a Chon(a Korean inch, 寸) unit. The slope of long common rafter that is formed between the perimeter and interior columns was grasped with limits of a definite value. This is that the perimeter column is trimmed to a Chon unit, as Yeongchunheon(迎春軒), In the roof frame of Korean traditional timber architecture, the slope of rafter, first of all, is to decide the slope of long common rafter and then to decide a height of ridge piece settled whole height of a building. And it is regulated with position and height of a post so as to set up middle rafter. Especially, the slope of long common rafter, it is not to be decide through scale of a building but through a length of the perimeter column and composition of bracket structure. And in case middle rafter, the process of its slope is to devide the central bay on the side of a building into equality, and then to adjust position and length of a post.

Heating and Cooling Energy Demand Evaluating of Standard Houses According to Layer Component of Masonry, Concrete and Wood Frame Using PHPP (PHPP를 활용한 조적, 콘크리트, 목조 레이어 구성별 표준주택 냉·난방 에너지 요구량 평가)

  • Kang, Yujin;Lee, Junhee;Lee, Hwayoung;Kim, Sumin
    • Journal of the Korean Wood Science and Technology
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    • v.45 no.1
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    • pp.1-11
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    • 2017
  • A lot of the energy are consumed on heating and cooling in buildings. The buildings need to minimize the heating and cooling loads for $CO_2$ emissions and energy consumption reduction. In recently, also demand of detached houses were increase while the residential culture was changed. The structure of the domestic detached houses can be divided into masonry, concrete, wood frame houses. Therefore, in this study, the heating and cooling load and energy demand were analyzed on the equal area detached house consisting of three structural methods (Masonry, Concrete, Wood frame). Layer of wall, roof, and floor were composited by structure. Thermal transmittance (U-value) of each layer was using the PHPP calculation for considering stud, such as the wood frame wall. In addition, the case of without considering for studs in wood frame wall (Non-studs) was analyzed in order to compare the difference between studs or not. Analysis was performed using self-developed heating and cooling load calculation program (CHLC) based excel and ECO2. The results of cooling and heating load and energy demand showed the highest values in the wood frame structure, and the concrete structure were confirmed to maintain a high value secondly. Two structure were determined to be disadvantageous on the energy consumption. Consequently, the masonry structure have an advantage over the other structure under the identical conditions. It was determined that if the except for thermal bridges due to the studs in the wood frame structure, it can be reduced the energy consumption.

Seismic response analysis of reinforced concrete frames including soil flexibility

  • Jayalekshmi, B.R.;Poojary, V.G. Deepthi;Venkataramana, Katta;Shivashankar, R.
    • Structural Engineering and Mechanics
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    • v.48 no.1
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    • pp.1-16
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    • 2013
  • The seismic response of RC space frame structures with isolated footing resting on a shallow soil stratum on rock is presented in this paper. Homogeneous soil stratum of different stiffness in the very soft to stiff range is considered. Soil, footing and super structure are considered to be the parts of an integral system. A finite element model of the integrated system is developed and subjected to scaled acceleration time histories recorded during two different real earthquakes. Dynamic analysis is performed using mode superposition method of transient analysis. A parametric study is conducted to investigate the effect of flexibility of soil in the dynamic behaviour of low-rise building frames. The time histories and Fourier spectra of roof displacement, base shear and structural response quantities of the space frame on compliant base are presented and compared with the fixed base condition. Results indicate that the incorporation of soil flexibility is required for the realistic estimate of structural seismic response especially for single storey structures resting on very soft soil.

A Study on Designed Landscape Characteristics of Le Corbuiser's Architecture in Mountain and Residential Area (산간지역과 주거지에 입지하는 르 코르비지에 건축의 의도된 경관특징 연구)

  • Chong, Geon-Chai
    • Journal of the Korean Institute of Rural Architecture
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    • v.22 no.3
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    • pp.25-32
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    • 2020
  • The purpose of this study is to understand what Le Corbuiser has intended on a panoramic landscape view through his modern architectural design. This paper is willing to improve that he considered both natural and local landscape scenery, when he designed architecture with drawing images. He designed various ways to see outside scenery and community culture through ribbon windows, piloti, architectural promenade, picture frame, and rooftop garden as the angle of view inside the building, 'designed landscape panorama' from his architecture. Therefore the contents of the study include the analysis of the local landscapes shown through his architecture by photograph, drawing of a real scenery, and his sketches with biology to find what he has intended. The following conclusions have three points. First, Le Corbuiser has a basic idea to bear a natural and local scenery from his architecture through five points of new architecture. Second, pilotis, ribbon windows, and roof garden with picture frame and architectural promenade are pathways of his architecture to see 'designed landscape panorama'. Third, it comes from his early architecture like Villa Savoye in 1920s to Couvent de Sainte Marie de la Tourette in 1950s, but Ronchamp church converts his idea on previous thoughts.

Effects of the isolation parameters on the seismic response of steel frames

  • Deringol, Ahmet H.;Bilgin, Huseyin
    • Earthquakes and Structures
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    • v.15 no.3
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    • pp.319-334
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    • 2018
  • In this paper, an analytical study was carried out to propose an optimum base-isolated system for the design of steel structures equipped with lead rubber bearings (LRB). For this, 5 and 10-storey steel moment resisting frames (MRFs) were designed as Special Moment Frame (SMF). These two-dimensional and three-bay frames equipped with a set of isolation systems within a predefined range that minimizes the response of the base-isolated frames subjected to a series of earthquakes. In the design of LRB, two main parameters, namely, isolation period (T) and the ratio of strength to weight (Q/W) supported by isolators were considered as 2.25, 2.5, 2.75 and 3 s, 0.05, 0.10 and 0.15, respectively. The Force-deformation behavior of the isolators was modelled by the bi-linear behavior which could reflect the nonlinear characteristics of the lead-plug bearings. The base-isolated frames were modelled using a finite element program and those performances were evaluated in the light of the nonlinear time history analyses by six natural accelerograms compatible with seismic hazard levels of 2% probability of exceedance in 50 years. The performance of the isolated frames was assessed in terms of roof displacement, relative displacement, interstorey drift, absolute acceleration, base shear and hysteretic curve.

The Structural Design of Tianjin Goldin Finance 117 Tower

  • Liu, Peng;Ho, Goman;Lee, Alexis;Yin, Chao;Lee, Kevin;Liu, Guang-lei;Huang, Xiao-yun
    • International Journal of High-Rise Buildings
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    • v.1 no.4
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    • pp.271-281
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    • 2012
  • Tianjin Goldin Finance 117 tower has an architectural height of 597 m, total of 117 stories, and the coronation of having the highest structural roof of all the buildings under construction in China. Structural height-width ratio is approximately 9.5, exceeding the existing regulation code significantly. In order to satisfy earthquake and wind-resisting requirements, a structure consisting of a perimeter frame composed of mega composite columns, mega braces and transfer trusses and reinforced concrete core containing composite steel plate wall is adopted. Complemented by some of the new requirements from the latest Chinese building seismic design codes, design of the super high-rise building in high-intensity seismic area exhibits a number of new features and solutions to professional requirements in response spectrum selection, overall stiffness control, material and component type selection, seismic performance based design, mega-column design, anti-collapse and stability analysis as well as elastic-plastic time-history analysis. Furthermore, under the prerequisite of economic viability and a series of technical requirements prescribed by the expert review panel for high-rise buildings exceeding code limits, the design manages to overcome various structural challenges and realizes the intentions of the architect and the client.

Shake table tests on a non-seismically detailed RC frame structure

  • Sharma, Akanshu;Reddy, G.R.;Vaze, K.K.
    • Structural Engineering and Mechanics
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    • v.41 no.1
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    • pp.1-24
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    • 2012
  • A reinforced concrete (RC) framed structure detailed according to non-seismic detailing provisions as per Indian Standard was tested on shake table under dynamic loads. The structure had 3 main storeys and an additional storey to simulate the footing to plinth level. In plan the structure was symmetric with 2 bays in each direction. In order to optimize the information obtained from the tests, tests were planned in three different stages. In the first stage, tests were done with masonry infill panels in one direction to obtain information on the stiffness increase due to addition of infill panels. In second stage, the infills were removed and tests were conducted on the structure without and with tuned liquid dampers (TLD) on the roof of the structure to investigate the effect of TLD on seismic response of the structure. In the third stage, tests were conducted on bare frame structure under biaxial time histories with gradually increasing peak ground acceleration (PGA) till failure. The simulated earthquakes represented low, moderate and severe seismic ground motions. The effects of masonry infill panels on dynamic characteristics of the structure, effectiveness of TLD in reducing the seismic response of structure and the failure patterns of non-seismically detailed structures, are clearly brought out. Details of design and similitude are also discussed.