• Title/Summary/Keyword: Habitat structure

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A Study on Optimum Distribution of Story Shear Force Coefficient for Seismic Design of Multi-story Structure

  • Oh, Sang Hoon;Jeon, Jongsoo
    • International Journal of High-Rise Buildings
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    • v.3 no.2
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    • pp.121-145
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    • 2014
  • The story shear force distributions of most seismic design codes generally reflect the influences of higher vibration modes based on the elastic deformations of structures. However, as the seismic design allows for the plastic behavior of a structure, the story shear force distribution shall be effective after it is yielded due to earthquake excitation. Hence this study conducted numerical analyses on the story shear force distributions of most seismic design codes to find out the characteristics of how a structure is damaged between stories. Analysis results show that the more forces are distributed onto high stories, the lower its concentration is and the more energy is absorbed. From the results, this study proposes the optimum story shear force distribution and its calculation formula that make the damages uniformly distributed onto whole stories. Consequently, the story damage distribution from the optimum calculation formula was considerably more stable than existing seismic design codes.

Four New Species of Dictyoceratid Sponges (Demospongiae) from Korea

  • Lee, Kyung-Jin;Sim, Chung-Ja
    • Animal cells and systems
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    • v.11 no.1
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    • pp.55-60
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    • 2007
  • Four new species, Semitaspongia jejuensis, Scalarispongia regularis, S. nigra and Dysidea violata are described from Jejudo, Korea. They were collected from 15 m depth by SCUBA diving and from intertidal area by hand. Semitaspongia jejuensis n. sp. is easily distinguished from other Semitaspongia species in growth form, conules, colour, skeletal structure, diameter of fibre and habitat. Scalarispongia regularis n. sp. is very close to S. scalaris (Schmidt, 1862) in skeletal structure, but S. scalaris has longer conules, larger meshes, longer distance between primary fibres, and highly developed subdermal canal system. Scalarispongia nigra n. sp. is very close to S. regularis in skeletal structure but can be easily distinguished by its black colour of external surface and growth form. Dysidea violata n. sp. is similar with D. ethria (Laubenfels, 1936) in sponge appearance, but D. etheria is clearly defined by its blue colour and thickness of fibre.

Structural Design of Mid-Story SI Tall-building with RC Frame Placed on Steel Structure

  • Isobe, Tomonobu;Aono, Hideshi
    • International Journal of High-Rise Buildings
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    • v.10 no.3
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    • pp.173-178
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    • 2021
  • In this paper we introduce Shinagawa HEART, located in Shinagawa district, Tokyo. It is a mixed-use building with residences on the upper floors, offices on the lower floors, and commercial uses on the first and second floors, and is intended to meet the various needs of a building on the border between residential and commercial areas. The upper floors of the building are made of reinforced concrete, while the middle and lower floors are made of steel with CFT columns. First, an overview of the structural plan of the building is presented. Next, the adoption of the middle layer seismic isolation and the switch between the lower steel structure and the upper reinforced concrete structure, which are the features of this building, are explained. Finally, the construction method adopted to achieve the design performance is explained.

Practical Experience with Full-scale Performance Verification of Dynamic Vibration Absorbers installed in Tall Buildings

  • Love, J.S.;Morava, B.
    • International Journal of High-Rise Buildings
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    • v.10 no.2
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    • pp.85-92
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    • 2021
  • Dynamic vibration absorbers (DVAs) in the form of tuned sloshing dampers (TSDs) and tuned mass dampers (TMDs) are commonly used to reduce the wind-induced motion of high-rise buildings. Full-scale performance of structure-DVA systems must be evaluated during the DVA commissioning process using structural monitoring data. While the random decrement technique (RDT) is sometimes employed to evaluate the DVA performance, it is shown to have no theoretical justification for application to structure-DVA systems, and to produce erroneous results. Subsequently, several practical methods with a sound theoretical basis are presented and illustrated using simulated and real-world data. By monitoring the responses of the structure and DVA simultaneously, it is possible to directly measure the effective damping of the system or perform system identification from which the DVA performance can be evaluated.

Shenzhen Rural Commercial Bank Headquarters: an Iconic Tower Defined by the Integration of Architecture, Structure and Sustainability Goals

  • Besjak, Charles;Thewis, Alexandra
    • International Journal of High-Rise Buildings
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    • v.11 no.1
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    • pp.31-39
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    • 2022
  • The seamless integration of the architecture and structure of a tall building plays a key role in establishing a recognizable and iconic design. The structural system developed for Shenzhen Rural Commercial Bank Headquarters (SRCBH) utilizes enhanced structural innovations unique to the tower's geometry to improve structural and sustainability performance. SRCBH utilizes a steel diagrid system pulled outside of the enclosure line with diaphragm forces resolved primarily by corner diagonal beams. During the design process the structural systems underwent performance based design and optimization for wind and seismic loading. Resiliency was prioritized for structural design as well as fire resistance. More closely integrating the structure of a building with its architecture and sustainability goals can lead to unique and innovative towers with a timeless expression.

Stability of Diagrid Structures

  • Rahimian, Ahmad
    • International Journal of High-Rise Buildings
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    • v.5 no.4
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    • pp.263-270
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    • 2016
  • In this paper, the stability requirements for diagrid and mega braced structures are examined. The role of the secondary bracing system for the stability of a diagrid structure is discussed. A simple procedure is proposed for the design of the secondary bracing system when it is required. As a case study, the design of the Hearst Tower diagrid and its secondary bracing system are presented.

Challenge in the Structural Design of Suzhou IFS

  • Zhou, Jianlong;Huang, Yongqiang
    • International Journal of High-Rise Buildings
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    • v.10 no.3
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    • pp.165-171
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    • 2021
  • Core-outrigger-mega frame system is used in Suzhou IFS with 95-story, 450 m-tall, which is beyond Chinese code limit. Besides simple introduction on design principle, structure system and analysis, key techniques including performance based design criteria, frame shear ratio, capacity check of mega column, human comfort criteria under wind induced vibration and TSD design were presented in details for reference of similar super tall building design.

Fluctuating Wind Pressures on High Aspect Ratio Circular Cylinder

  • Keisuke Miura;Masahiro Matsui
    • International Journal of High-Rise Buildings
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    • v.11 no.4
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    • pp.277-286
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    • 2022
  • In this study, The POD technique was applied to the fluctuating wind pressure of high aspect ratio circular cylinder to consider about its organizational structure, and considered about the characteristics of the fluctuating wind force obtained by synthesized the POD modes.

Comparison Habitat Preference for Small Mammals around the Hyeongsan River (형산강 수계 주변 소형 포유류의 서식지 선호도 비교)

  • 정철운;이정일
    • The Korean Journal of Ecology
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    • v.27 no.3
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    • pp.133-139
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    • 2004
  • This study was conducted to clarify the preference and habitat condition of small mammals at the Hyeongsan river in Ulsan, Gyeongju, and Pohang from January 2003 to July 2003. In the study sites, total 111 individuals of Apodemus agrarius, Rattus norvegicus, and Micromys minutus were captured in study sites. The most abundant species were Apodemus agrarius, 79.2 percent, among the captured small mammals. Density of habitation was significantly higher in agricultural land than in either private house or woods. However, they were more abundant in paddy Weld area than in agricultural land. A number of captured small mammals were higher in herbaceous rather than three other vegetation types. Existent of river embankment and its type were important factors affecting the spatial distribution of the individuals. Preference of small mammals were significantly lower in revetment block area rather than in none or nature-stone mat area. There was significantly correlationship between the depth of water and the number of captured small mammals. A number of captured small mammals were clearly increased in reference to decreasing depth of water in study site, in conclusion, the following factors such as the vegetation structure, depth of water, types of land use and types of river dike could be affected the spatial distribution of small mammals in the study sites.

The Evaluation of River Naturalness for Biological Habitat Restoration : I. Proposal of Evaluation Method (하천의 생물서식처 복원을 위한 하천자연도평가 : I. 평가방법의 제안)

  • Park, Bong-Jin;Shin, Jong-Iee;Jung, Kwan-Sue
    • Journal of Korea Water Resources Association
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    • v.38 no.1
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    • pp.37-48
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    • 2005
  • The evaluation methods of river naturalness were reviewed, and one of the best methods was applied to three sample rivers-Narinchun, Bokhachun, Anyangchun. As a result, Narinchun with well preserved state, Bokhachun with being to restoration stage from the damaged, Anyangchun with severe damaged state showed 2$^{nd}$ , 3$^{rd}$ and 4$^{th}$ Grade. The application result shows the method is reliable for evaluating the damaged habitat in river. The method was improved on the evaluation items to apply lager river systems. This suggested method have 14 evaluation items with two category-river shape and river environment and five different Grades for evaluation degree according to state of natural closeness. The every 2,000-3,000m along the river system is recommended as the interval of evaluation unit. According to calssification of evaluation items, this method can supply various information related to river environment and ecology such as ecological deformation and diversity, cross sectional structure and continuity of river shapes..