• Title/Summary/Keyword: high rise buildings

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A Study on the Effects of All-in-one Automatic Fire Shutters Installed in High School on Evacuation Time

  • Lee, Soon Beom;Kong, Ha Sung;Lee, Jai Young
    • International Journal of Internet, Broadcasting and Communication
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    • v.14 no.3
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    • pp.182-192
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    • 2022
  • This study analyzed the effects of the all-in-one automatic fire shutter (hereinafter referred to as "all-in-one shutter") installed along the fire compartment in a five-story high school building on the evacuation time by using the Pathfinder simulation program. When the all-in-one shutter was added as a new variable, the evacuation time was delayed, indicating insufficient evacuation safety. The evacuation time exceeded the appropriate standard when the evacuation exit was designated to the students in the present state of being placed on the 2nd, 3rd, and 4th floors and the all-in-one shutter was activated. When students were placed on the 1st, 2nd and 3rd floors under the same conditions, the evacuation time was also greatly exceeded. However, when the width of the entrance was set to 130cm, the evacuation time was almost the same as when the all-in-one shutter was not installed. In high-rise school buildings, the bottleneck caused by all-in-one shutters is becoming a major factor in evacuation barriers. To ensure the evacuation safety of school buildings, it has been judged that evacuation education and training to predict the evacuation time required through the all-in-one shutter entrance and induce an evacuation procedure suitable for the standard evacuation time should be carried out in parallel. The implications of this study and suggestions for effective fire compartments and follow-up studies were discussed.

A Review and Analysis of the Thermal Exposure in Large Compartment Fire Experiments

  • Gupta, Vinny;Hidalgo, Juan P.;Lange, David;Cowlard, Adam;Abecassis-Empis, Cecilia;Torero, Jose L.
    • International Journal of High-Rise Buildings
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    • v.10 no.4
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    • pp.345-364
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    • 2021
  • Developments in the understanding of fire behaviour for large open-plan spaces typical of tall buildings have been greatly outpaced by the rate at which these buildings are being constructed and their characteristics changed. Numerous high-profile fire-induced failures have highlighted the inadequacy of existing tools and standards for fire engineering when applied to highly-optimised modern tall buildings. With the continued increase in height and complexity of tall buildings, the risk to the occupants from fire-induced structural collapse increases, thus understanding the performance of complex structural systems under fire exposure is imperative. Therefore, an accurate representation of the design fire for open-plan compartments is required for the purposes of design. This will allow for knowledge-driven, quantifiable factors of safety to be used in the design of highly optimised modern tall buildings. In this paper, we review the state-of-the-art experimental research on large open-plan compartment fires from the past three decades. We have assimilated results collected from 37 large-scale compartment fire experiments of the open-plan type conducted from 1993 to 2019, covering a range of compartment and fuel characteristics. Spatial and temporal distributions of the heat fluxes imposed on compartment ceilings are estimated from the data. The complexity of the compartment fire dynamics is highlighted by the large differences in the data collected, which currently complicates the development of engineering tools based on physical models. Despite the large variability, this analysis shows that the orders of magnitude of the thermal exposure are defined by the ratio of flame spread and burnout front velocities (VS / VBO), which enables the grouping of open-plan compartment fires into three distinct modes of fire spread. Each mode is found to exhibit a characteristic order of magnitude and temporal distribution of thermal exposure. The results show that the magnitude of the thermal exposure for each mode are not consistent with existing performance-based design models, nevertheless, our analysis offers a new pathway for defining thermal exposure from realistic fire scenarios in large open-plan compartments.

Physical Properties of 50MPa and 80MPa Ternary High Strength Concretes before and after Concrete Pumping

  • Lee, Bum-Sik;Kim, Seong-Deok;Jun, Myoung-Hoon;Park, Sung-Sik;Park, Su-Hee;Jung, Sang-Jin
    • Journal of the Korea Institute of Building Construction
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    • v.12 no.4
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    • pp.451-459
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    • 2012
  • At the Korea Land and Housing Corporation(LH), concretes with high design strength of 50 MPa and 80 MPa that are composed only of ordinary Portland cement, blast furnace slag, and fly ash are developed. To determine whether the developed high strength concretes have the same properties when they are produced in batch plant(B/P) condition in the ready mixed concrete plant, and as existing high strength concretes, field tests are performed and material properties are evaluated. To investigate the material properties of the high strength concretes before and after pumping, compressive strength, flowability, air content, hydration temperature, pumping and compactability are evaluated. In field tests, before and after pumping, flowability satisfied the relevant criteria. In terms of air content, while it was slightly decreased after pumping, it satisfied the requirements. Hydration temperature criteria were satisfied, and compactability was excellent as well. The study found that the developed ternary high strength concretes have the same properties as existing high strength concretes. They can also be useful for the construction of high-rise buildings, as they are economical.

A Study on Manufacture standardization of High Strength Concrete to Use Moderate Heat Portland Cement (벨라이트계 시멘트를 이용한 고강도 콘크리트 제조표준화에 관한 연구)

  • Park, Cheol;Kim, Dong-Suck;Um, Tai-Sun;Lee, Jong-Ryul
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.665-668
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    • 2008
  • Recently the city construction and the concrete structures are more becoming extra weight and the efficient use of the space by the population intensively and follow in industrial intensive commerce and the residence commerce composition building which leads the high story of the building. Consequently the high rise of the building which space applies efficiently in objective which will increase continuously. Also with high rise of buildings durability it will be able to increase the life of the structure is emphasized and the concrete structure is demanding the more high strength.

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Free Vibration Analysis of Stiffened Tapered Thick Plates with Concentrated Masses (집중질량을 갖는 변단면 보강 후판의 자유진동해석)

  • Lee, Yong-Soo;Kim, Il-Jung;Oh, Soog-Kyoung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.8
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    • pp.828-837
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    • 2009
  • Recently, as high-rise buildings increase steeply, sub-structures of them are often supported on elastic foundation(in a case of pasternak foundation or winkler foundation). And there are many machines in sub-structures of buildings and slabs of sub-structures are affected by vibration which they make. This paper deals with vibration of plates on elastic foundation. Machines on plates are considered as concentrated mass. This paper has the object of investigating natural frequencies of tapered thick plate on pasternak foundation by means of finite element method and providing kinetic design data for mat of building structures. Free vibration analysis that tapered thick plate with Concentrated Masses in this paper. Finite element analysis of rectangular plate is done by use of rectangular finite element with 8-nodes. In order to analysis plate which is supported on pasternak foundation. The Winkler parameter is varied with 10, $10^2$, $10^3$ and the shear foundation parameter is 5, 10. This paper is analyzed varying thickness by taper ratio. The taper ratio is applied as 0.0, 0.25, 0.5, 0.75, 1.0. And the Concentrated Mass is applied as P1, Pc, P2 respectively.

A Study on the Behavior of High-rise Buildings Considering Soil-Structure Interaction (지반-구조물 상호작용을 고려한 고층 구조물의 거동에 관한 연구)

  • Kim, Se-Hyun;Park, Sung-Soo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.9 no.4
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    • pp.243-251
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    • 2005
  • In the seismic design the pile foundation system of the buildings generally have been modeled to have a fixed end for its convenience and conservativeness. But it is necessary to consider the soil-structure interaction for more reliable design. In this study, the framed tube building and brace tube building with pile foundation system under earthquake were analyzed considering soil-structural interaction by 3 pile foundation modeling methods; fixed-end model, 6 springs model and p-y springs model. And 2 soil conditions were used in analysis. For each cases, displacements, drifts, maximum stress, periods and 1st mode mass participation ratios were compared.

A Study on Performance-Based Design Enforcement (성능위주설계 시행의 개선방안)

  • Lee, Yang-Ju;Ko, Kyoung-Chan;Park, Woe-Chul
    • Fire Science and Engineering
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    • v.26 no.1
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    • pp.68-73
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    • 2012
  • Performance-based design (PBD) for large scale high rise buildings has been enforced to secure fire and evacuation safety since July 1, 2011. As various types of trial and error were expected in the early stage, to suggest solutions to the problems that might be followed by the enforcement, the regulations on PBD were reviewed and a questionnaire survey to fire protection specialists was carried out. It was confirmed that PBD is required for large scale apartment buildings, and specific and detail criteria for PBD methodology and evaluations, education for PBD to personnel who design and evaluate are also in need.

A Study on Evaluation of Horizontal Force of Non-structural Components Considering Predominant Periods of Seismic Waves (지진파 탁월주기를 고려한 비구조요소의 수평설계지진력 평가)

  • Oh, Sang Hoon;Kim, Ju Chan
    • Journal of the Earthquake Engineering Society of Korea
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    • v.24 no.6
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    • pp.267-275
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    • 2020
  • In the event of an earthquake, non-structural components require seismic performance to ensure evacuation routes and to protect lives from falling non-structural components. Accordingly, the seismic design code proposes horizontal force for the design and evaluation of non-structural components. Ground motion observed on each floor is affected by a building's eigen vibration mode. Therefore, the earthquake damage of non-structural components is determined by the characteristics of the non-structural component system and the vibration characteristics of the building. Floor response spectra in the seismic design code are estimated through time history analysis using seismic waves. However, it is difficult to use floor response spectra as a design criterion because of user-specific uncertainties of time history analysis. In addition, considering the response characteristics of high-rise buildings to long-period ground motions, the safety factor of the proposed horizontal force may be low. Therefore, this study carried out the horizontal force review proposed in the seismic design code through dynamic analysis and evaluated the floor response of seismic waves considering buildings and predominant periods of seismic waves.

Structural Health Monitoring of Shanghai Tower Considering Time-dependent Effects

  • Zhang, Qilin;Yang, Bin;Liu, Tao;Li, Han;Lv, Jia
    • International Journal of High-Rise Buildings
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    • v.4 no.1
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    • pp.39-44
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    • 2015
  • This paper presents the structural health monitoring (SHM) of Shanghai Tower. In order to provide useful information for safety evaluation and regular maintenance under construction and in-service condition, a comprehensive structural health monitoring (SHM) system is installed in Shanghai Tower, which is composed of a main monitoring station and eleven substations. Structural responses at different construction stages are measured using this SHM system and presented in this study. Meanwhile, a detailed finite element model (FEM) is created and comparison of results between SHM and FEM is carried out. Results indicate that the time-dependent property of concrete creep is of great importance to structural response and the measured data can be used in FEM updating to obtain more accurate FEM models at different construction stages. Therefore, installation of structural health monitoring system in super-tall buildings could be considered as an effective way to assure structural safety during the construction process.

Heavy-weight Impact Noise Reduction of Concrete Slab Reinforcement Using F.R.P (F.R.P 재료 보강에 의한 신개념 중량충격음 저감대책)

  • Jeong, Jeong-Ho;Yoo, Seung-Yup;Lee, Pyoung-Jik;Jeon, Jin-Yong;Jo, A-Hyoung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.383-386
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    • 2005
  • Low frequency heavy-weight impact noise is the most irritating noise in Korean high-rise reinforced concrete apartment buildings. This low frequency noise is generated by foot traffic due to the fact that Koreans do not wear shoes at home. The transmission of the noise is facilitated by a load bearing wall structural system without beams and columns which is used in these buildings. In order to control low frequency heavy-weight impact noise, floating floors using isolation materials such as glass-wool mat and poly-urethane mat are used. However, it was difficult to control low frequency heavy-weight impact sound using isolation material. In this study, reinforcement of concrete slab using beams and plate was conducted. Using the FEM analysis, the effect of concrete slab reinforcement using FRP(fiber-glass reinforced plastic) on the bang machine impact vibration acceleration level and sound were conducted at the standard floor impact sound test building. The $3{\sim}4dB$ floor impact vibration acceleration level and impact sound pressure level were reduced and the natural frequency of slabs were changed.

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