필로티 반자 내 화재 시 단열재 화염확산 특성연구

김홍식(Hong-Sik Kim),오부열(Bu-Yeol Oh),박민영(Min-Young Park) 한국화재소방학회 2020 한국화재소방학회논문지 Vol.34 No.5

In piloti-type structures, large-scale fires frequently occur because insulation materials in the ceiling are ignited. However,the spread of fire in these cases is not well known. Therefore, this study conducted small-scale (1.0 m × 1.0 m) tests andreal-scale model tests. According to the results, we clarified the fire spread, temperature variation over time, and the effectsof insulation materials in fire sites. For the small-scale tests, the internal structure of the ceiling was extruded polystyrene(XPS) + sheet molding compound (SMC), retardant expanded polystyrene (Retardant EPS) + sheet molding compound(SMC), and extruded polystyrene (XPS) + design metal ceiling (DMC). From the small-scale and large-scale tests thatsimulated a fire in a piloti-type structure, the flow of heat in the interior space and the cause of a large fire were identified. The tests were conducted with EPS+DMC, defined as the best-case scenario, and XPS+SMC, defined as the worst-casescenario during a fire accident. The results from the tests showed that combustion began when the insulation material wasexposed to the fire source. Then, molten XPS fell onto the SMC, establishing a new fire source that destroyed the ceilingmaterial, leading to increased combustion due to the inflow of oxygen. 본 논문에서는 필로티 구조 건축물의 천장(반자 위) 공간 내부를 모사한 축소모형과 실대화재 실험을 통해 천장(반자 위) 단열재, 천장재에 따른 화재확산의 정도, 시간에 따른 온도변화를 확인하였다. 축소모형 실험의 천장공간내부구조는 압출법 단열재(XPS 단열재) + 열경화성수지 천장재(SMC), 난연 비드법 단열재(난연 EPS) + 열경화성수지 천장재(SMC), 그리고 압출법 단열재(XPS) + 아연도금강판 천장재(DMC)로 예비실험을 진행하였다. 이를 바탕으로 필로티 구조 건축물 화재를 모사한 실대화재 실험을 통해 천장(반자 위) 내부 공간에서의 열의 유동 파악, 대형화재로의 확산 원인을 확인하였다. 실대화재 실험은 화재 사고를 가정하여 최상의 경우인 난연 EPS 단열재 + DMC천장재와 최악의 경우인 XPS 단열재 + SMC 천장재로 진행하였다. 실험결과, 화원에 노출된 단열재에서부터 연소가시작되어 용융된 압출법 단열재(XPS)가 열결화성수지 천장재(SMC)로 낙하하면서 새로운 화원을 형성하고 천장재가탈락하며 산소 유입에 의해 연소 확대로 이어졌다.

아라미드 섬유시트로 기둥 보강된 필로티 구조물의 내진성능 평가

양근혁,문주현,임채림,노광근 한국구조물진단유지관리공학회 2023 한국구조물진단유지관리공학회 논문집 Vol.27 No.6

이 연구의 목적은 필로티 건축물에서 아라미드 섬유시트의 연성보강 효과를 평가하는데에 있다. 필로티 구조물은 총 2개가 제작되었으며, 반복 횡하중 정적 실험으로 휨 거동을 평가하였다. 연성보강 효과는 횡하중-변위관계, 변위연성비, 일손상지수 및 비틀림 거동으로부터 검증되었다. 실험결과 기둥이 아라미드 섬유시트로 보강된 필로티 건축물은 최대하중 이후 기둥에서 효과적인 구속효과로 전단파괴 방지및 비틀림이 최소화되었으며, 전반적으로 연성적인 거동을 보였다. 결과적으로 기둥이 아라미드 섬유시트로 보강된 필로티 건축물의 변위연성비 및 일손상지수는 보강되지 않은 필로티 건축물보다 각각 4.63배 및 42.81배 높았다. This study is to evaluate the ductility strengthening effect of aramid fiber sheets on piloti-type structures. Two piloti-type structure specimens were prepared and tested under statical cyclic lateral loads. The ductility strengthening effect was validated from the analysis of lateral load-displacement relationship, displacement ductility ratio, work damage index and torsion behavior. Test results showed that the post-peak behavior of piloti-type structures with columns strengthened with aramid fiber sheets tended to be ductile resulting from preventing shear failure and minimizing torsion due to the effective lateral confinement of column concrete by aramid fiber sheet. Consequently, the displacement ductility ratio and work damage index of piloti-type structures with columns with strengthened with aramid fiber sheets were 4.63 and 42.81 times higher than those of non strengthened piloti-type structures.

필로티 건축물의 지진취약도평가를 통한 변위기반 한계상태 분석

손정훈(Sohn, JungHoon),최인섭(Choi, Insub),김준희(Kim, JunHee) 대한건축학회 2022 대한건축학회논문집 Vol.38 No.6

Evaluating the seismic performance of a piloti-type structure is difficult considering the drift-based limit states such as interstory drift ratio and initial design review (IDR) of piloti-type structures are not defined. Drift-based limit states are defined for a lateral-resisting system, but piloti-type structures consist of two lateral-resisting systems. This study aims to analyze the suitability of existing drift-based limit states through the fragility assessment for piloti-type building structures. The piloti structures consisting of a shear wall system and a RC moment frame were used as a prototype model. IDR and concrete strain were used as the engineering demand parameter (EDP) to analyze the seismic fragility of target buildings through an incremental dynamic analysis (IDA). As a result of the correlation analysis of the seismic fragility curves obtained by IDR and concrete strain, the IDR-based limit states of a piloti-type structure should be lower than that of the practically used shear wall system.

필로티 R/C 건물의 구조설계에서 본 구조특성 조사 연구 - 부산지역에서 신축된 건물을 중심으로 -

전대한 대한건축학회지회연합회 2018 대한건축학회연합논문집 Vol.20 No.2

필로티형 건물은 도심지의 상업 겸용 주거건물의 주차장 확보를 위해 대도시에서 많이 건설되고 있는 대표적인 주거건물이다. 2017년 10월 포항지진에서 필로티 구조물의 지진피해가 두드러지게 나타났다. 현재 국내에서 설계되고 있는 필로티 건물은 지진하중이 지배적인 하중이며, 동적 모드해석에 의해 비틀림이 심하게 발생하고 수직비정형의 영향으로 내진성능은 매우 취약한 것으로 인식되고 있다. 본 연구에서는 국내에서 구조설계가 완료되어 건축 허가된 필로티 건물의 구조설계 현황을 조사하여, 구조설계에 적용된 내진설계 자료를 파악하는 것이 목적이다. 본 연구에서 사용된 구조설계 데이터는 2016~2017년 부산지역에서 건축 허가된 중, 저층 필로티 건물이다. 본 연구에서 얻어진 결과는 다음과 같다. 1)국내에서 설계되고 있는 필로티구조의 단위면적당 중량은 15~25kN/m2로 나타났다. 2)등가정적해석의 근사고유주기와 동적모드해석의 1차고유주기는 편차가 매우 큰 것을 알 수 있다. 3)지진응답계수는 동일 고유주기 건물에서 편차는 상당히 큰 것을 알 수 있었다. 4)설계용 지진하중을 결정하는 보정 지진응답계수는 1.0~1.9정도의 범위에 있다. The piloti-type R/C building is a typical residential building that is being built in large urban area in order to install the parking lot of commercial residential building in downtown area. In October of 2017, earthquake damage of piloti-type structure was considerably observed in Pohang Earthquake of Korea. It is recognized that the seismic load is the predominant lateral load in the piloti-type buildings currently being designed in Korea, and the seismic performance is very weak due to the effect of vertical irregularity and the dynamic mode analysis leads to distortion. The purpose of this study is to investigate the structural design status of piloti-type buildings that have been approved for construction in Korea and to grasp the seismic design data applied to structural design. The structural design data used in this study is a medium and low-rise piloti-type building permitted in Busan area from 2016 to 2017. The results obtained in this study are as follows. 1) The weight per unit area of the piloti-type building designed in Korea is 15~25kN/m2. 2) It can be seen that the deviation between the approximate natural period used in the equivalent static analysis and the first natural period using the dynamic mode analysis is very large. 3) The deviation of the base shear force coefficient was considerably large even in the same height building. 4) The base shear scale factor to determine the design seismic load is in the range of 1.0~1.9.

Limit states of RC structures with first floor irregularities

Favvata, Maria J.,Naoum, Maria C.,Karayannis, Chris G. Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.6

The seismic performance of reinforced concrete (RC) frame structures with irregularities leading to soft first floor is studied using capacity assessment procedures. The soft first story effect is investigated for the cases: (i) slab-column connections without beams at the first floor, (ii) tall first story height and (iii) pilotis type building (open ground story). The effects of the first floor irregularity on the RC frame structure performance stages at global and local level (limit states) are investigated. Assessment based on the Capacity Spectrum Method (ATC-40) and on the Coefficient Method (FEMA 356) is also examined. Results in terms of failure modes, capacity curves, interstory drifts, ductility requirements and infills behaviour are presented. From the results it can be deduced that the global capacity of the structures is decreased due to the considered first floor morphology irregularities in comparison to the capacities of the regular structure. An increase of the demands for interstory drift is observed at the first floor level due to the considered irregularities while the open ground floor structure (pilotis type) led to even higher values of interstory drift demands at the first story. In the cases of tall first story and slab-column connections without beams soft-story mechanisms have also been observed at the first floor. Rotational criteria (EC8-part3) showed that the structure with slab-column connections without beams exhibited the most critical response.

Limit states of RC structures with first floor irregularities

Maria J. Favvata,Maria C. Naoum,Chris G. Karayannis 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.6

The seismic performance of reinforced concrete (RC) frame structures with irregularities leading to soft first floor is studied using capacity assessment procedures. The soft first story effect is investigated for the cases: (i) slab-column connections without beams at the first floor, (ii) tall first story height and (iii) pilotis type building (open ground story). The effects of the first floor irregularity on the RC frame structure performance stages at global and local level (limit states) are investigated. Assessment based on the Capacity Spectrum Method (ATC-40) and on the Coefficient Method (FEMA 356) is also examined. Results in terms of failure modes, capacity curves, interstory drifts, ductility requirements and infills behaviour are presented. From the results it can be deduced that the global capacity of the structures is decreased due to the considered first floor morphology irregularities in comparison to the capacities of the regular structure. An increase of the demands for interstory drift is observed at the first floor level due to the considered irregularities while the open ground floor structure (pilotis type) led to even higher values of interstory drift demands at the first story. In the cases of tall first story and slab-column connections without beams softstory mechanisms have also been observed at the first floor. Rotational criteria (EC8-part3) showed that the structure with slab-column connections without beams exhibited the most critical response.

4차산업혁명 건설IT융합기술기반 내진성능향상을 위한 Bridge System CFT 개발 및 드론을 이용한 건축물 성능검토

김대건 ( Kim Dae-geon ),장유경 ( Jang Yu-gyeong ),문원규 ( Moon Won-kyu ),이다솔 ( Lee Da-sol ),박수빈 ( Park Su-bin ),이동운 ( Lee Dong-oun ) 한국건축시공학회 2018 한국건축시공학회 학술발표대회 논문집 Vol.18 No.1

Unlike the projects that the government has implemented recently to develop new cities under the New Deal project, Saeddeul Village projects to improve the environment of the city are gaining attention. The problem has been found to be that many of the buildings in Saeddeul Village are still not earthquake-proof by using drones to review the state of the town. It also revealed that after two years of earthquakes, Pilotis structures are the most vulnerable to earthquakes. However, it is suitable for small spaces in the city because it provides parking spaces as well as residential spaces. Accordingly, the focus should be on repair and reinforcement rather than reconstruction. In this study, a concrete-based seismic design and construction method is developed in the columns of the existing pylotis structure.

필로티 건축물의 지진취약도평가를 통한 변위기반 한계상태 분석

손정훈(Sohn, Jung-Hoon),최인섭(Choi, Insub),김준희(Kim, JunHee) 대한건축학회 2020 대한건축학회 학술발표대회 논문집 Vol.40 No.2

It is difficult to determine the limit states for the piloti-type building structures consisting of two lateral-resisting systems since the existing drift-based limit states (i.e., interstory drift ratio, IDR) are defined for a lateral-resisting system. This study aims to analyze the existing drift-based limit states through the fragility assessment for piloti-type building structures. The piloti structures consisting of a shear wall system and a RC moment frame was used as a prototype model. The incremental dynamic analysis (IDA) was performed using IDR and concrete strain as the engineering demand parameter (EDP) of the target buildings. The fragility assessment was performed using seismic demand and limit states derived through IDA. As a result, the limit states suitable for the piloti-type building structures should be less than that of the shear wall system in practice.

필로티구조 도시형생활주택의 화재위험성에 관한 연구 -의정부사례를 바탕으로-

황의청 ( Hwang Eu-cheong ),권영진 ( Kwon Young-jin ) 한국건축시공학회 2017 한국건축시공학회 학술발표대회 논문집 Vol.17 No.1

The Urban-type building is an building that it relaxed the construction standard and subsidiary facility standard. The most of the urban-type buildings are pilotis, the main case of representing these building`s fire risk is the Uijeongbu fire this study investigated to piloti urban type housing risk on the basis of Uijeongbu fire, and we checked structural problem that unable to escape from the rooftop inside the piloti. also, there was confirmed limit to the evacuation of the occupants because the smoke was rapidly transferred to the top layer through inside the electric duct. and when we analyzed smoke flow use of Fire simulation, it was confirmed Available Safety Egress Time that is four minutes of CO.

시간-등가 방법을 이용한 필로티 구조물의 차량화재에 대한 공간온도평가

이한솔,신진원,최인락,민정기,최성모 한국강구조학회 2024 韓國鋼構造學會 論文集 Vol.36 No.1

본 연구에서는 차량화재의 노출된 필로티건축물의 CFRP기둥을 대상으로 표준화재와 차량화재의 크기를 비교하기 위하여FDS-ABAQUS Coupling을 이용한 열해석을 진행하였다. 열해석 모델은 INS-10mm 모델과 , Non-INS 모델로 평가를 진행하였다. 이후 차량화재와 표준화재의 크기를 비교하였고, 표준화재를 이용한 성능기반 내화설계를 진행하기 위하여 시간-등가방법 중, 등가면적개념, 최대온도 개념을 이용하여 등가노출시간을 구하였다. 등가 노출 시간은 우선적으로 파괴기준이 명확한 부재 FRP와 철근을 대상으로 비교하였으며, FRP는 60분, 철근은 75분으로 등가시간이 나타났다. 이는 표준화재를 60분, 75분동안 화재를 노출시킬 경우 차량화재의 노출된 것과 동일한 값을 얻을 수 있는 것으로 판단된다. 정확한 등가노출시간을 구하기 위해서는 등가에너지개념 및 최소강도개념을 이용하여 등가노출시간을 구한 뒤 시간-등가 방법들 간의 비교를 진행하여 효율적인 시간-등가방법을 찾는 것이 중요하다고 판단된다. This study presents a thermal analysis conducted using FDS-ABAQUS coupling to assess the effect of vehicle fire compared to a standard fire on exposed CFRP columns of a piloti structure. The thermal analysis model was evaluated with a 10mm insulation model and a non-insulation model. Subsequently, the temperature effects of the vehicle fire and standard fire were compared. To conduct performance-based fire-resistant design using the standard fire, equivalent exposure times were determined using the time-equivalent method, employing the concepts of equivalent exposure area and maximum temperature. The equivalent exposure times were initially compared for FRP and steel reinforcement, both of which have clear failure criteria. The equivalent exposure time for FRP was found to be 60 minutes, while for steel reinforcement, it was 75 minutes. This suggests that exposing the standard fire for 60 or 75 minutes would yield equivalent results to those observed in a vehicle fire. To accurately determine equivalent exposure times, it is crucial to use the concepts of equivalent energy and minimum strength to calculate the equivalent exposure times and then compare various time-equivalent methods to find an efficient approach.