• 제목/요약/키워드: 3D Building construction

검색결과 729건 처리시간 0.024초

The use of cost-benefit analysis in performance-based earthquake engineering of steel structures

  • Ravanshadnia, Hamidreza;Shakib, Hamzeh;Ansari, Mokhtar;Safiey, Amir
    • Earthquakes and Structures
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    • 제22권6호
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    • pp.561-570
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    • 2022
  • It is of great importance to be able to evaluate different structural systems not only based on their seismic performance but also considering their lifetime service costs. Many structural systems exist that can meet the engineering requirements for different performance levels; therefore, these systems shall be selected based on their economic costs over time. In this paper, two structural systems, including special steel moment-resisting and the ordinary concentric braced frames, are considered, which are designed to meet the three performance levels: Immediate Occupancy (IO), Life Safety (LS), Collapse Prevention (CP). The seismic behavior of these two systems is studied under three strong ground motions (i.e., Tabas, Bam, Kajour earthquake records) using the Perform3D package, and the incurred damages to the studied systems are examined at two hazard levels. Economic analyses were performed to determine the most economical structural system to meet the specified performance level requirements, considering the initial cost and costs associated with damages of an earthquake that occurred during their lifetime. In essence, the economic lifetime study results show that the special moment-resisting frames at IO and LS performance levels are at least 20% more economical than braced frames. The result of the study for these building systems with different heights designed for different performance levels also shows it is more economical from the perspective of long-term ownership of the property to design for higher performance levels even though the initial construction cost is higher.

초고강도 섬유보강 콘크리트 분절형 박스거더의 연성 거동 (Ductile Behavior of Ultra High Performance Fiber Reinforced Concrete Segmental Box Girder)

  • 정민선;박성용;한상묵
    • 한국건설순환자원학회논문집
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    • 제5권3호
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    • pp.282-289
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    • 2017
  • 압축강도 160MPa와 길이 15.4m를 가진 초고강도 섬유보강 분절 박스거더에 대한 휨거동 실험을 수행하였다. 실험 변수로는 PS강재의 면적, 강섬유 혼입률과 복부와 상부 플랜지의 종방향 철근이다. 하부플랜지의 두 개 텐던에 16개, 12개, 7개씩을 배치하고, 강섬유 혼입률은 2.0%, 1.5%, 1%를 사용하였다. 하부에 32개의 강연선을 배근한 박스거더는 과보강 강재 거동을 보였으며, 24개의 강연선을 배근한 거더는 강연선 32개를 설치한 거더와 비슷한 최대하중을 보이면서 처짐이 많은 저보강 강재 거동을 보였다. 강연선을 14개 설치한 박스거더는 24개 설치한 거더 내하력의 1/2정도 최대하중을 보이며, 연성거동을 보이고 있다. 설계기준의 강재지수에 따른 보 파괴거동의 분류에 대한 식의 유효성을 검토한 결과 지수 판별식은 초고강도 박스거더의 거동을 정확하게 반영하지 못하고 있으며, 박스거더의 기하학적 형태를 세부적으로 고려하고, 강재의 변형률 0.005에 해당하는 기준값을 새로 산정해야할 것으로 판단된다.

전단보강이 없는 순환골재 철근콘크리트 보의 전단거동에 관한 연구 (A Study on the Shear Behavior of Recycled Aggregate Reinforced Concrete Beams without Stirrups)

  • 이정훈;김우석;백승민;강현구;곽윤근
    • 콘크리트학회논문집
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    • 제25권4호
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    • pp.389-400
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    • 2013
  • 몇몇 연구자들에 의해 순환골재를 사용한 철근콘크리트 보의 전단거동에 대한 연구가 수행되었다. 이 실험에서는 건물 구조체에 순환골재 콘크리트의 적용 가능성과 전단 성능에 대하여 조사하였다. 일반적으로, 전단보강이 없는 철근콘크리트 보의 전단강도는 콘크리트의 압축강도, 인장철근비 및 전단경간비의 영향을 받는다. 이 연구에서는, 전단보강이 없는 28개의 순환골재 철근콘크리트 보를 2점 가력하여 실험하였다. 순환골재 치환율(0, 15, 30, 50%), 전단경간비(a/d=2, 3, 4) 및 인장철근비(${\rho}$=0.80, 1.27, 1.84%)를 변수로 하였고, 순환골재 치환율 50%를 기준으로 압축강도 30 MPa을 목표로 배합하였다. 이 연구가 순환 골재 철근콘크리트 보의 전단설계식 제정에 기초적 자료로써 중요한 역할을 할 수 있을 것으로 생각된다.

신라시대 교량 월정교 교각기초의 복원안정성 연구 (A Study on the Stability of Foundation for Piers of WoljungGyo Bridge Built in Ancient Silla)

  • 이광우;홍기권;유승경
    • 한국지반신소재학회논문집
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    • 제18권4호
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    • pp.273-286
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    • 2019
  • 신라의 수도인 경주에 서기 760년에 건설된 것으로 알려진 월정교에 대한 복원공사가 최근 완료되었다. 고문헌에 따르면, 월정교는 축조 이후 고려시대인 서기 1280년까지 약 520년 동안 사용된 것으로 보인다. 월정교지에서는 양측 교대와 4개의 교각기초 및 한두단의 교각석이 발견되었다. 발견된 교각기초 중 하나는 상당한 부등침하가 일어난 상태였다. 따라서 월정교의 안전한 복원을 위해서는 부등침하의 원인을 밝히는 것이 매우 중요하다. 이에 본 연구에서는 월정교 복원공사에 앞서, 지층상태 파악을 위한 시추조사, 2차원 지반강성 평가를 위한 표면파시험, 지지력 평가를 위한 대형평판재하시험 등 광범위한 현장조사를 수행하였다. 지반조사 결과를 바탕으로 기초안정성 평가를 위한 3차원 유한요소해석을 실시하였다. 연구결과, 월정교 교각기초의 하부지반은 월정교 복원에 따른 하중에 대해 지지력 및 침하에 충분한 안전율을 가진 것으로 평가되었다. 따라서 교각기초 하부지반에 대한 추가적인 보강은 필요하지 않은 것으로 판단되며, 복원에 앞서 부등침하가 발생한 교각기초 하부에 자갈을 이용한 평탄화 작업은 실시할 필요가 있다.

만성 중이염의 수술시 소견에 대한 임상통계적 관찰 (CLINICOSTATISTICAL ANALYSIS OF SURGICAL FINDINGS IN CHRONIC OTITIS MEDIA)

  • 최덕주;전병훈;민원식;함태영
    • 대한기관식도과학회:학술대회논문집
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    • 대한기관식도과학회 1987년도 제21차 학술대회 연제순서 및 초록
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    • pp.6-6
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    • 1987
  • 만성중이염은 현재 그 빈도가 줄어드는 추세에 있으나 아직도 이과 영역에서 큰 비중을 차지하는 질환이다. 또한 청력개선, 정상구조의 보존, 병변 제거의 목적을 위하여 대부분 수술적 요법이 필요하게 된다. 이에 저자들은 본 병원에서 시행한 만성 중이염 451예, 남자 238예, 여자 213예. 진주종성 중이염 170예, 비진주종성 중이염 273예에 대한 수술시 소견에 대한 임상 통계적 관찰을 한 바, 다음과 같은 결과를 얻었다. 1) 관찰대상을 술식별로 분류하면 진주종성 중이염과 비진주종성 중이염의 비가 $\circled1$ Myningoplasty ; 19.1% : 0%, $\circled2$ Tympanoplasty without mastoidectomy ; 34.5% : 14.4%, $\circled3$ Tympanoplasty with mastoidectomy ; 3.0% :12.1% 이었다. 2) 고막천공부위는, 진주종성 중이염과 비진주종성 중이염의 비가 변연부천공이 10.1% : 5.5%, 상고실천공이 38.8% : 1.4%, 중심부천증이 12.9% : 47.3%, 전천공이 32.5% : 39.6%, 고막유착이 5.6% : 6.2% 을 보였다. 3) 이소골의 상태는 진주종성중이염과 비진주종성 중이염의 비가, 모든 이소골의 손실은 26.6% : 4.3%, 모든 이소골이 정상에 가까운 예는 16.6% : 69.3%, 가장 병변이 심했던 침골 이상은 76.9% : 24.8% 를 보였다. 4) 중이강 점막소견은 진주종성 중이염과 비진주종성 중이염의 비가, 정상에 가까운 예가 16.7% : 47.0%, 병적 소견을 보인 예가 83.3% : 53.0% 이었다. 5) 진주종성 중이염과, 비진주종성 중이염에서의 안면신경관노출은 2.2% : 0.3%, 뇌막노출은 9.5% : 2.9%, 횡정맥동노출은 5.0% : 1.1%, 미로누공은 1.7% : 0% 이었다.lant, engineering service business can be said "The Software of Total Industry." Engineering service is what is called a higher business which offers specialized engineering know-how and experience. Engineering service compaines offer Its specialized knowledge and experience to government, industry and commerce. Whether the task is to modernize plant equipment, to design a building or to manage construction, an engineering company will develop and implement the most appropriate and cost effective solution. Clients use the engineering service of firm knowing that the engineer′s professional judgement is not influenced or biased by other commercial affiliations. While benefiting from the diverse experience that professional engineers can apply to a specific problem, government and industry also reduce the need for permanent in-house engineering staff. Engineering firms may be specialized or multi-disciplinary.도말표본에서와 같이 제 14 일 이전에는 호중구가, 그 이후에는 단핵구가 주종을 이루었다.>18.9dB

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PHC 항타말뚝의 하중저항계수 산정 (Assesment of Load and Resistance Factored Design Value for PHC Driven Pile)

  • 박종배;박용부;이범식;김상연
    • 토지주택연구
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    • 제4권3호
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    • pp.279-286
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    • 2013
  • 기성 말뚝을 항타시공하는 방법은 시공비가 적게 들면서도 우수한 지지력을 얻을 수 있는 효율적인 시공방법이다. 하지만 국내와 같이 매립층이 많고 다양한 지반조건에서는 예상치 못한 문제로 인하여 기계적 굴착이 수반되는 매입공법으로 변경되기도 한다. 따라서, 항타공법이 매입말뚝에 비하여 불확실성이 더 높을 수 있다. 본 논문에서는 국내에서 건축물의 기초로 사용되고 있는 PHC 항타말뚝의 불확실성 요인을 줄여주고 보다 신뢰성 있는 설계가 가능하도록 하기 위하여 한계상태설계법의 일종인 하중저항계수법(LRFD) 설계정수를 산정하였다. PHC 항타말뚝의 LRFD 설계정수를 제안하기 위해 총 221회(초기동재하 : 93회, 재항타동재하 : 128회)의 동재하시험자료와 이들 말뚝에 대한 지지력 설계(Meyerhof 설계법, SPT-CPT 전환 설계법) 자료를 분석하고 목표 신뢰도 지수 2.33과 3.0에 대해 하중저항계수를 제시하였다. PHC 항타말뚝의 저항계수는 목표 신뢰도 지수에 따라 Meyerhof 방법, SPT-CPT 전환법은 각각 0.43~0.55 및 0.40~0.49를 나타내었다.

터널근접시공에 의한 말뚝의 거동을 고려한 플랫폼 기반의 예비 설계 가이드라인에 대한 연구 (A study on platform-based preliminary design guidelines associated with the behaviour of piles to adjacent tunnelling)

  • 전영진;이규설;이재철;바트보양;이철주
    • 한국터널지하공간학회 논문집
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    • 제24권2호
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    • pp.129-151
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    • 2022
  • 본 연구에서는 기초판으로 연결된 군말뚝 형태의 기초 하부를 터널이 근접 통과할 경우 이로 인해 발생하는 말뚝의 거동을 파악하기 위하여 3차원 유한요소해석을 수행하였다. 이때 터널과 말뚝기초 사이의 지반보강을 조건별로 고려하여 수치해석을 수행함으로써 결과를 분석하였다. 수치해석에서는 터널 굴착으로 발생하는 말뚝의 침하, 축력, 전단응력 및 상대변위를 고찰하였으며, 추가적으로 IoT 플랫폼 예비 설계 가이드라인을 제시하였다. 지반보강을 고려하지 않으며 터널로부터 이격거리가 가장 가까운 말뚝은 지반보강을 가장 크게 고려하고 터널로부터 이격거리가 가장 멀리 존재한 말뚝에 비해 말뚝두부의 침하가 약 70% 크게 발생하였다. 또한, 말뚝 품질관리 요소 데이터는 수집 및 정제과정을 통해 다양한 형태의 API (Application Programming Interface)로 제공되었으며, 각 데이터 플로우 프로세스를 정의하여 데이터가 생성되는 시점에 따라 적합한 API를 제공하는 것이 중요한 것으로 분석되었다. 본 연구를 통하여 기초판으로 연결된 군말뚝의 거동에 영향을 미치는 주요 인자를 보강조건에 따라 심도 있게 고찰하고, 말뚝의 품질관리 IoT 플랫폼을 제시하였다.

A Study on the Implement of AI-based Integrated Smart Fire Safety (ISFS) System in Public Facility

  • Myung Sik Lee;Pill Sun Seo
    • 국제초고층학회논문집
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    • 제12권3호
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    • pp.225-234
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    • 2023
  • Even at this point in the era of digital transformation, we are still facing many problems in the safety sector that cannot prevent the occurrence or spread of human casualties. When you are in an unexpected emergency, it is often difficult to respond only with human physical ability. Human casualties continue to occur at construction sites, manufacturing plants, and multi-use facilities used by many people in everyday life. If you encounter a situation where normal judgment is impossible in the event of an emergency at a life site where there are still many safety blind spots, it is difficult to cope with the existing manual guidance method. New variable guidance technology, which combines artificial intelligence and digital twin, can make it possible to prevent casualties by processing large amounts of data needed to derive appropriate countermeasures in real time beyond identifying what safety accidents occurred in unexpected crisis situations. When a simple control method that divides and monitors several CCTVs is digitally converted and combined with artificial intelligence and 3D digital twin control technology, intelligence augmentation (IA) effect can be achieved that strengthens the safety decision-making ability required in real time. With the enforcement of the Serious Disaster Enterprise Punishment Act, the importance of distributing a smart location guidance system that urgently solves the decision-making delay that occurs in safety accidents at various industrial sites and strengthens the real-time decision-making ability of field workers and managers is highlighted. The smart location guidance system that combines artificial intelligence and digital twin consists of AIoT HW equipment, wireless communication NW equipment, and intelligent SW platform. The intelligent SW platform consists of Builder that supports digital twin modeling, Watch that meets real-time control based on synchronization between real objects and digital twin models, and Simulator that supports the development and verification of various safety management scenarios using intelligent agents. The smart location guidance system provides on-site monitoring using IoT equipment, CCTV-linked intelligent image analysis, intelligent operating procedures that support workflow modeling to immediately reflect the needs of the site, situational location guidance, and digital twin virtual fencing access control technology. This paper examines the limitations of traditional fixed passive guidance methods, analyzes global technology development trends to overcome them, identifies the digital transformation properties required to switch to intelligent variable smart location guidance methods, explains the characteristics and components of AI-based public facility smart fire safety integrated system (ISFS).

Stellite bearings for liquid Zn-/Al-Systems with advanced chemical and physical properties by Mechanical Alloying and Standard-PM-Route

  • Zoz, H.;Benz, H.U.;Huettebraeucker, K.;Furken, L.;Ren, H.;Reichardt, R.
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2000년도 춘계학술강연 및 발표대회 강연 및 발표논문 초록집
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    • pp.9-10
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    • 2000
  • An important business-field of world-wide steel-industry is the coating of thin metal-sheets with zinc, zinc-aluminum and aluminum based materials. These products mostly go into automotive industry. in particular for the car-body. into building and construction industry as well as household appliances. Due to mass-production, the processing is done in large continuously operating plants where the mostly cold-rolled metal-strip as the substrate is handled in coils up to 40 tons unwind before and rolled up again after passing the processing plant which includes cleaning, annealing, hot-dip galvanizing / aluminizing and chemical treatment. In the liquid Zn, Zn-AI, AI-Zn and AI-Si bathes a combined action of corrosion and wear under high temperature and high stress onto the transfer components (rolls) accounts for major economic losses. Most critical here are the bearing systems of these rolls operating in the liquid system. Rolls in liquid system can not be avoided as they are needed to transfer the steel-strip into and out of the crucible. Since several years, ceramic roller bearings are tested here [1.2], however, in particular due to uncontrollable Slag-impurities within the hot bath [3], slide bearings are still expected to be of a higher potential [4]. The today's state of the art is the application of slide bearings based on Stellite\ulcorneragainst Stellite which is in general a 50-60 wt% Co-matrix with incorporated Cr- and W-carbides and other composites. Indeed Stellite is used as the bearing-material as of it's chemical properties (does not go into solution), the physical properties in particular with poor lubricating properties are not satisfying at all. To increase the Sliding behavior in the bearing system, about 0.15-0.2 wt% of lead has been added into the hot-bath in the past. Due to environmental regulations. this had to be reduced dramatically_ This together with the heavily increasing production rates expressed by increased velocity of the substrate-steel-band up to 200 m/min and increased tractate power up to 10 tons in modern plants. leads to life times of the bearings of a few up to several days only. To improve this situation. the Mechanical Alloying (MA) TeChnique [5.6.7.8] is used to prOduce advanced Stellite-based bearing materials. A lubricating phase is introduced into Stellite-powder-material by MA, the composite-powder-particles are coated by High Energy Milling (HEM) in order to produce bearing-bushes of approximately 12 kg by Sintering, Liquid Phase Sintering (LPS) and Hot Isostatic Pressing (HIP). The chemical and physical behavior of samples as well as the bearing systems in the hot galvanizing / aluminizing plant are discussed. DependenCies like lubricant material and composite, LPS-binder and composite, particle shape and PM-route with respect to achievable density. (temperature--) shock-reSistibility and corrosive-wear behavior will be described. The materials are characterized by particle size analysis (laser diffraction), scanning electron microscopy and X-ray diffraction. corrosive-wear behavior is determined using a special cylinder-in-bush apparatus (CIBA) as well as field-test in real production condition. Part I of this work describes the initial testing phase where different sample materials are produced, characterized, consolidated and tested in the CIBA under a common AI-Zn-system. The results are discussed and the material-system for the large components to be produced for the field test in real production condition is decided. Outlook: Part II of this work will describe the field test in a hot-dip-galvanizing/aluminizing plant of the mechanically alloyed bearing bushes under aluminum-rich liquid metal. Alter testing, the bushes will be characterized and obtained results with respect to wear. expected lifetime, surface roughness and infiltration will be discussed. Part III of this project will describe a second initial testing phase where the won results of part 1+11 will be transferred to the AI-Si system. Part IV of this project will describe the field test in a hot-dip-aluminizing plant of the mechanically alloyed bearing bushes under aluminum liquid metal. After testing. the bushes will be characterized and obtained results with respect to wear. expected lifetime, surface roughness and infiltration will be discussed.

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교사환경기준에 관한 연구 (A Study on Environmental Standards of School Building)

  • 홍석표;박영수
    • 한국학교ㆍ지역보건교육학회지
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    • 제1권1호
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    • pp.11-43
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    • 2000
  • The purpose of this study was, through analyzing the previous researches, to grasp the present status of environment of school building(ESB), research the sundry records of each element and, through comparative analysis of the standard of ESB in Korea, the United States, and Japan, select the normative standard of ESB, to clarify the point at issue presented in Regulation of Construction & facility Management for Elementary and and Secondary School in Korea, and to suggest an alternative preliminary standard of ESB. To carry out a research for this purpose, these were required: 1. to investigate the existing present status of ESB, 2. to make a comparative analysis of the standard of ESB in each country, 3. to suggest the normative standard of preliminary standard of ESB, 4. to analyze the controversial points of the standard of ESB in Korea, 5. to suggest an alternative preliminary standard of ESB. The conclusions were as follows: 1. Putting, through analyzing the previous researches, the existing present status of ESB together, it seemed that lighting environment, indoor air environment and noise environment were all in poor conditions. 2. In the result of a comparative analysis of the standard of ESB in Korea, Japan and the United States, in Korea the factors of each lighting and indoor air environment were not presented properly, in Japan, in lighting environment aspect, the standard on natural lighting and the factors on brightness were not presented., and in the USA the essential factors of each environment were throughly presented. In the comparison of the standards on each factor, Korea showed that the standard level presented was less properly prescribed than those of the USA and Japan but it also showed that the standard levels prescribed in the USA and in Japan were mostly similar to the standard levels in records investigated. 3. With the result of the normative standard selection on School Builiding environment factor of prescribed in this study, the controversial points of the standard of ESB in Korea were analyzed and the result was utilized to suggest new preliminary standard of ESB. 4. As the result of the analysis of the controversial points of the standard of ESB in Korea, it was found that the standard of ESB in Korea should be established on a basis of School Health Act and be concretely presented in School Health Regulation and School Health Rule. The factors of each environment was improperly presented in the existing standard of ESB in Korea. Moreover the standard of them was inferior to that of the records investigated and those of in the USA and in Japan and it also showed that the standard of it in Korea was improper to maintain Comfortable Learning Environment. 5. A suggested preliminary standard of ESB acquired through above study as follows: 1) In this study a new kind of preliminary standard of ESB is divided into lighting environment, indoor air environment, noise environment, odor environment and for above classification, reasonable factor and standard should be established and the controling way on each standard and countermeasures against it should be considered. 2) In lighting environment, the factors of natural lighting are divided into daylight rate, brightness, glare. In the standard on each factor, daylight rate should secure 5% of a mean daylight rate and 2% of a minimum daylight rate, brightness ratio of maximum illumination to minimum illumination should be under 10:1, and in glare there should not be an occurrence factor from a reflector outside of the classroom. And the factors of unnatural lighting are illumination, brightness, and glare. In the standard on each factor, illumination should be 750 lux or more, brightness ratio should be under 3 to 1, and glare should not occur. And Optimal reflection rate(%) of Colors and Facilities of Classroom which influences lighting environment should be considered. 3) In indoor air environment factors, thermal factors are divided into (1) room temperature, (2) relative humidity, (3) room air movement, (4) radiation heat, and harmful gases (5) CO, (6) $CO_2$ that are proceeded from using the heating fuel such as oval briquettes, firewood, charcoal being used in most of the classroom, and finally (7) dust. In the standard on each factor, the next are necessary; room temperature: $16^{\circ}C{\sim}26^{\circ}C$(summer : $E.T18.9{\sim}23.8^{\circ}C$, winter: $E.T16.7{\sim}21.7^{\circ}C$), relative humidity: $30{\sim}80%$, room air movement: under 0.5m/sec, radiation heat: under $5^{\circ}C$ gap between dry-bulb temperature and wet-bulb temperature, below 1000 ppm of ca and below 10ppm of $CO_2$, dust: below 0.10 $mg/m^3$ of Volume of dust in indoor air, and ventilation standard($CO_2$) for purification of indoor air : once/6 min.(about 7 times/40 min.) in an airtight classroom. 4) In the standard on noise environment, noise level should be under 40 dB(A) and the noise measuring way and the countermeasures against it should be considered. 5) In the standard on odor environment, odor level under Physical Method should be under 2 degrees, and the inspecting way and the countermeasures against it should be considered.

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