• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.104-104
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• 2015

국내 외에서 생태 수리해석 및 생태 서식 조건을 충족시키기 위한 최적 생태유량 (생태 유지유량) 산정에 대한 연구는 다양하게 진행되어 왔다. 그러나 상대적으로 생태 유지유량을 확보하기 위한 연구는 기존의 방법에서 크게 변화하지 못하고 있는 실정이다. 하천 유지유량을 확보하는 방안은 신규 댐/저수지 개발, 하수처리장 방류수 활용 등과 같은 직접 확보 방안과 댐/저수지 운영 효율 개선, 하천 유수점용허가 관리 등과 같은 간접 확보 방안으로 구분할 수 있다. 그러나 도시 하천에서 유지유량을 확보하기 위해 기존의 방법을 적용하는 것은 현실적으로 한계가 있다. 본 연구는 2차원 물리서식처 모형인 River2D를 이용하여, 물리서식처가 생태유량에 미치는 영향을 분석하였다. 대상구간은 한강의 제1지류인 홍제천으로 선정하였으며, 대상 구간은 하수처리장 방류수를 통해 유지유량이 확보되고 있으며, 추가적인 유지유량을 확보하기 현실적으로 어려운 구간이다. 물리서식처가 생태유량에 미치는 영향을 파악하기 위하여 현재 상태와 추가적인 물리서식처를 고려한 2차원 물리서식처 모의를 진행하였다. 이를 통해 물리서식처를 추가적으로 적용할 경우 현재 상태대비 물리 서식환경이 증가되어 생태유량이 일정부분 확보되는 것으로 나타났다. 본 연구는 도시하천에 물리 서식처를 도입하여 생태 서식공간이 증가함으로써 생태유량을 확보할 수 있는 방안에 대한 방법론을 제시할 수 있을 것으로 기대된다.

• International Journal of High-Rise Buildings
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• v.10 no.4
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• pp.251-263
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• 2021

Fire safety engineering is a critical specialization to include in the design of a tall building yet is often excluded from the Building Information Model (BIM) and integrated design process. The design of fire safety systems is interdependent with building/structural geometry, HVAC, mechanical, and electrical systems. A BIM is a 3D visual representation that stores data on these kinds of systems. The compatibility between BIM and fire safety design seems obvious yet has received a dearth of attention in structural (fire) engineering literature. The authors herein have reviewed over 40 recent papers on utilizing BIM for fire safety engineering, focusing on contemporary literature to obtain a more up-to-date review of the state-of-the-art. The resulting trends, technologies, research gaps, and methodologies are presented in this paper. Adoption of BIM in fire safety engineering is slow and behind other disciplines which may be improved if research involved more industry partners. For BIM technology to reach its potential, industry manufacturers need to provide high LOD fire BIM objects, fire engineers and researchers need to collaborate on future advancements, and building owners/management need to be educated on how to use the benefits provided.

• International Journal of High-Rise Buildings
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• v.10 no.4
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• pp.299-310
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• 2021

External fire spread has the potential to breach vertical compartmentation and violate the fire safety strategy of a building. The traditional design solution to this has been the use of non-combustible materials and spandrel panels but recent audits show that combustible materials are widespread and included in highly complex systems. Furthermore, most jurisdictions no longer require detailing of spandrel panels under many different circumstances. These buildings require rapid investigation using rational scientific methods to be able to adequately classify the fire risk. In this work, we use an extensive experimental campaign of material-scale data to explore the critical parameters driving upward flame spread. Two criteria are outlined using two different approaches. The first evaluates the time to ignition and the time to burnout to assess the ability for a fire to spread, and can be easily determined using traditional means. The second evaluates the preheated flame length as the critical parameter driving flame spread. A wide range of cladding materials are ranked according to these criteria to show their potential propensity to flame spread. From this, designers can use conservative approaches to perform fire risk assessments for buildings with combustible materials or can be used to aid decision-making. Precise estimates of flame spread rates within complex façade systems are not achievable with the current level of knowledge and will require a substantial amount of work to make progress.

• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.287-298
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• 2018

High strength steels have been widely applied in recent years due to high strength and good working performance. When subjected to fire conditions, the strength and elastic modulus of high strength steels deteriorate significantly and hence the load bearing capacity of structures reduces at elevated temperatures. The reduction factors of mechanical properties of high strength steels are quite different from mild steels. Therefore, the fire design methods deduced from mild steel structures are not applicable to high strength steel structures. In recent ten years, the first author of this paper has carried out a lot of fundamental research on fire behavior of high strength steels and structures. Summary of these research is presented in this paper, including mechanical properties of high strength steels at elevated temperature and after fire exposure, creep response of high strength steels at elevated temperature, residual stresses of welded high strength steel member after fire exposure, fire resistance of high strength steel columns, fire resistance of high strength steel beams, local buckling of high strength steel members, and residual strength of high strength steel columns after fire exposure. The results show that the mechanical properties of high strength steel in fire condition and the corresponding fire resistance of high strength steel structures are different from those of mild steel and structures, and the fire design methods recommended in current design codes are not applicable to high strength steel structures.

• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.299-311
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• 2018

As engineered timber such as Glulam is seeing increasing use in tall timber buildings, building codes are adapting to allow for this. In order for this material to be used confidently and safely in one of these applications, there is a need to understand the effects that fire can have on an engineered timber structural member. The post-fire resilience aspect of glulam is studied herein. Two sets of experiments are performed to consider the validity of zero strength guidance with respect to short duration fire exposure on thin glulam members. Small scale samples were heated in a cone calorimeter to different fire severities. These samples illustrated significant strength loss but high variability despite controlled quantification of char layers. Large scale samples were heated locally using a controlled fuel fire in shear and moment locations along the length of the beam respectively. Additionally, reduced cross section samples were created by mechanically carving a way an area of cross section equal to the area lost to char on the heated beams. All of the samples were then loaded to failure in four-point (laterally restrained) bending tests. The beams that have been burnt in the shear region were observed as having a reduction in strength of up to 34.5% from the control beams. These test samples displayed relatively little variability, apart from beams that displayed material defects. The suite of testing indicated that zero strength guidance may be under conservative and may require increasing from 7 mm up to as much as 23 mm.

• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.363-374
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• 2018

The façade is an important, complex, and costly part of a building, performing multiple objectives of value to the occupants, like protecting from wind, rain, sunlight, heat, cold, and sound. But the frequency of façade fires in large buildings is alarming, and has multiplied by seven times worldwide over the last three decades, to a current rate of 4.8 fires per year. High-performing polymer based materials allow for a significant improvement across several objectives of a facade (e.g., thermal insulation, weight, and construction time) thereby increasing the quality of a building. However, all polymers are flammable to some degree. If this safety problem is to be tackled effectively, then it is essential to understand how different materials, and the façade as a whole, perform in the event of a fire. This paper discusses the drivers for flammability in facades, the interaction of facade materials, and current gaps in knowledge. In doing so, it aims to provide an introduction to the field of façade fires, and to show that because of the drive for thermal efficiency and sustainability, façade systems have become more complex over time, and they have also become more flammable. We discuss the importance of quantifying the flammability of different façade systems, but highlight that it is currently impossible to do so, which hinders research progress. We finish by putting forward an integral framework of design that uses multi-objective optimization to ensure that flammability is minimized while considering other objectives, such as maximizing thermal performance or minimizing weight.

• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.313-325
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• 2018

Concrete-filled steel tubular (CFST) members are commonly used as composite columns in modern construction. However, the current guidelines for members' fire design (EN1994-1-2) have been proved to be unsafe in case the relative slenderness is higher than 0.5. In addition, the simplified design methods of Eurocode 4 are limited to circular and square CFST columns, while in practice columns with rectangular and elliptical hollow sections are being increasingly used because of their architectural aesthetics. In the last years a large experimental research has been carried out at Coimbra University on the topic. They have been tested concrete filled circular, square, rectangular and elliptical hollow columns with restrained thermal elongation. Some parameters such as the slenderness, the type of cross-section geometry as well as the axial and rotational restraint of the surrounding structure to the column have been tested in order to evaluate their influence on the fire resistance of such columns. In this paper it is evaluated the influence of the boundary conditions (pin-ended and semi-rigid end-support conditions) on the behavior of the columns in case of fire. In these tests it could not be seen a marked effect of the tested boundary conditions but it is believed that the increasing of rotational stiffness increases the fire resistance of the columns.

• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.327-342
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• 2018

Geopolymer concrete (GPC), which is recognised as an environmentally friendly alternative to ordinary Portland cement (OPC) concrete, has been reported to possess high fire resistance. However, very limited research has been conducted to investigate the behaviour of geopolymer concrete-filled steel tubular (GCFST) columns at either ambient or elevated temperatures. This paper presents the compressive test results of a total of 15 circular concrete-filled steel tubular (CFST) stub columns, including 5 specimens tested at room temperature, 5 specimens tested at elevated temperatures and the remaining 5 specimens tested for residual strength after exposure to elevated temperatures. The main variables in the test program include: (a) concrete type; (b) concrete strength; and (c) curing condition of geopolymer concrete. The test results demonstrate that GCFST columns have similar ambient temperature behaviour compared with the conventional CFST counterparts. However, GCFST columns exhibit better fire resistance than the conventional CFST columns. Meanwhile, it is found that the GCFST column made with heat cured GPC has lower strength loss than other columns after exposure to elevated temperatures. The research results highlight the possibility of using geopolymer concrete to improve the fire resistance of CFST columns.

• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.397-408
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• 2018

In a recent tragic fire incident, the Plasco Tower collapsed after an intense outburst of fire lasting for three and a half hours and claiming the lives of 16 firefighters and 6 civilians. This paper will present continuing collaborative work between Hong Kong Polytechnic University and Queen's University in Canada to model the progressive collapse of the tower. The fire started at the 10th floor and was observed to have travelled along the floor horizontally and through the staircase and windows vertically. Plasco Tower was steel structure and all the steel sections were fabricated by welding standard European channel or angle profiles and no fire protection was applied. Four internal columns carried the loads transferred by the primary beams, and box columns were constructed along the perimeter of the building as a braced tube for resisting seismic loading. OpenSees fibre-based sections and displacement-based beam-column elements are used to model the frames, while shell elements are used for the reinforced concrete floor slabs. The thermal properties and elevated temperature mechanical properties are as recommended in the Eurocodes. The results in this preliminarily analysis are based on rough estimations of the structure's configuration. The ongoing work looks at modeling the Plasco Tower based on the most accurate findings from reviewing many photographs and collected data.

• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.265-285
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• 2018

This paper presents a state-of-the-art review on the design, research and education aspects of fire safety engineering (FSE) with a particular concern on high-rise buildings. FSE finds its root after Great Fire of Rome in 64 AD, followed by Great London Fire in 1666. The development of modern FSE is continuously driven by industry revolution, insurance community and government regulations. Now FSE has become a unique engineering discipline and is moving towards performance-based design since 1990s. The performance-based fire safety design (PBFSD) involves identification of fire safety goals, design objectives, establishment of performance criteria, and selection of proper solutions for fire safety. The determination of fire scenarios and design fires have now become major contents for PBFSD. To experience a rapid and positive evolution in design and research consistent with other engineering disciplines, it is important for fire safety engineering as a profession to set up a special educational system to deliver the next-generation fire safety engineers. High-rise buildings have their unique fire safety issues such as rapid fire and smoke spread, extended evacuation time, longer fire duration, mixed occupancies, etc., bringing more difficulties in ensuring life safety and protection of property and environment. A list of recommendations is proposed to improve the fire safety of high-rise buildings. In addition, some source information for specific knowledge and information on FSE is provided in Appendix.