Full-scale fire tests of wooden 3-story school building

Transcription

1 Full-scale fire tests of wooden 3-story school building Tomohiro NARUSE Head, Fire Standards Division, Building Department, National Institute for Land and Infrastructure Management(NILIM), Ministry of Land, Infrastructure, Transport and Tourism (MLIT), Japan 1

2 1.Background 1 1/3 Act for Promotion of Use of Wood in Public Buildings During the 174th regular session of the Japanese Diet, the "Act for Promotion of Use of Wood in Public Buildings (2010, Law No. 36) was passed, and it went into effect on October 1 st For the survival and stable growth of forests and the sustainable use of woods, from the standpoint of environmental protection, the new Law obligates the national and local governments to utilize wood materials for public buildings that have 3-story (for limited use) or less. 2

3 Basic Policies for Promotion of Use of Wood in Public Buildings 2/3 Based on Article 7 of the "Act for Promotion of Use of Wood in Public Buildings", the Minister of Agriculture, Forestry and Fisheries and the Minister of Land, Infrastructure, Transport and Tourism shall establish the basic policies for the promotion of the use of wood in public buildings. These basic policies establish the essential points to be covered in promoting the use of wood in public buildings and the objectives of this promotion in public buildings which are developed and maintained by the national government; for example, one objective for the national government is to - as a rule - employ fully timber construction in those low-rise public buildings that fall within the scope of nation-controlled public buildings that are candidates for active timber construction promotion. 3

4 1.Background 2 3/3 Cabinet decision on policy related to addressing regulatory reform (June 18 th 2010) Requirement for fire-resistive construction by total floor area and number of stories of special building, especially for school, by Building Standard Law of Japan shall be reexamined depending on research results of fire performance of wood and wooden building. 4

5 2.Purpose of research project 1/3 Requirements by BSL (except for those by zoning) 3-story school buildings (Article 27. item1) or Wooden buildings exceeding 3,000 m 2 in total floor area(article21. item2) Fire-resistive building (Principal building parts : Fire-resistive construction) Putting the merit of wood to school buildings, 1) we are reconfirming requirements for 3-story school buildings, 2) we are gathering knowledge of fire performance of wood and timber for structural member and interior material. We are checking by fire tests whether the school building constructed by quasi-fire-resistive buildings can satisfy the requirements or not, relating to safe egress, support of fire fighting 5

6 2.Purpose of research project 2/3 Fire-resistive building Principal building parts are of fire-resistive construction. Fire doors in exterior walls liable to catch fire. Quasi fire-resistive building Principal building parts are of quasi fire-resistive construction. Fire doors in exterior walls liable to catch fire. Fire-resistive construction Performance is required during and after fire exposure. Quasi-fire-resistive construction Performance is required during 30, 45, or 60 minutes fire exposure. 6

7 2.Purpose of research project 3/3 Full-scale fire test of wooden 3-story school building [Purpose] By specifying fire safety requirements of wooden 3-story school building about 1) safe egress, 2) prevention of fire harm to neighbor (collapse, heat transfer, fire brands) and 3) support of fire fighting activity, and so on. We establish the technical standards of wooden 3-story school building by 3 full-scale fire tests. 7

8 3.Outline of full scale fire test (Preliminary test) 1/5 Site : NILIM(Tsukuba) Structure: Wooden 3-story construction(1hr quasi-fire resistive construction ) Area : 830m 2 (50mx16m, 15mHeight) : 2,260m 2 Date : February 22 nd :00a.m. start Weather : Fine 6~8 Humidity about 50% wind speed 4m/s (East) Fire origin Appearance before test Fire wall To ilet To ilet To ilet To ilet To ilet To let To ilet Axonometric projection 8

9 3.Outline of full scale fire test (Preliminary test) 2/5 Music 音楽室 room (3 rd story) Wood frame construction preparation 準備室 room Crafts room 家庭科室 Toile 階段 Toile 便所 Stairway t t Timber frame construction Fire wall Open space オープンスペース Open space オープンスペース Classroom 普通教室 Classroom 普通教室 Classroom 普通教室 Floor area 830m 2 (2 nd story) preparation preparation 準備室準備室 room room Science lab 理科室 図工室 Crafts room To 階段 Toile 便所 ilet Stairway t Open space オープンスペース Classroom 普通教室 Classroom 普通教室 assembly 集会ホール hall Well 吹き抜け hole 4m preparation 準備室 room Locker 更衣室 room 資料 印刷室 Archives Office 事務室 Plan 16m 4m 4m 4m Library 図書コーナー Computer パソコン教室 room Toile 階段 Toile 便所 Stairway t t Corridor 廊下 Teacher s 職員室 room Fire origin ( 出火源 ) Entrance 昇降口 (1 st story) 8m 8m 9m 8m 8m 8m 50m 注 9

10 3.Outline of full scale fire test (Preliminary test) 3/5 Appearance Wood finish wall and ceiling of wall frame construction are finished by gypsum board Interior finish 2.1m Exterior Wall Fiber reinforced cement siding Fire Wall It is jointed with other part to support horizontal force 10

11 0min. 2min. Ignition Flashover 4min. Glass of 2 nd story classroom broke 6min. Fire spread to classroom of 2 nd story 8min. Fire spread to classroom of 3 rd story 17min. 22min. 3.Outline of full scale fire test (Preliminary test) 4/5 Flame spread to opening of east side beyond fire wall Fire spread to wall frame construction part South Side 27min. 36min. 76min. 95min. 96min. 123min. Fire spread to east side beyond fire wall (whole building) Floor of 3 rd story fell down Collapse of timber frame construction part Collapse of wood frame construction part Collapse of fire wall Collapse of whole building Summary of result In early stage, fire spread all over the building. Fire spread through fire wall. Fire wall collapsed. and so on 11

12 3.Outline of full scale fire test (Preliminary test) 5/5 12

13 4.Outline of full scale fire test (Preparatory test) 1/5 From preliminary test, we found Early fire spread to upper stories through the external openings (about 4 minutes to the 2 nd story and about 6 minutes to the 3 rd story for flame spreading) Early fire spread through fire wall (about 18 minutes) Fire wall collapsed without freestanding (96 minutes). In order to address these issues, we did preparatory test to make interior materials except columns, beams and floors resistant to fire, to place balconies and eaves to upper part of openings of exterior wall and to separate fire wall structurally and change fire doors worked out as countermeasures. 13

14 4.Outline of full scale fire test (Preparatory test) 2/5 Site : Gero city, Gifu prefecture Structure: Wooden 3-story construction(1hr quasi- Area : 310m 2 (24mx12m, 15mHeight) : 850m 2 Date : November 25 th :00a.m. start Weather : Fine -2~4 Humidity 52~77% wind speed 0.4m/s (south west) Fiber reinforced 外壁 : 窯業系サイディング cement siding Fire wall 防火壁 Balcony バルコニー Steel structure Timber frame construction 24m 軸組工法 12m Axonometric projection 14

15 4.Outline of full scale fire test (Preparatory test) 3/5 Fire wall eaves 庇 Open space オープンスペース (3 rd story) Floor area 310m 2 About 40% area of preliminary test Stairway 階段 Stairway 階段 Classroom 普通教室 Classroom 普通教室バルコニー Balcony eaves 庇 Open space オープンスペース Classroom 普通教室 Classroom 普通教室 (2 nd story) バルコニー Balcony This is the part to check fire spread over fire wall. Plan (1 st story) 12m 4m 4m 4m Corridor 廊下 Teacher s 職員室 room Stairway 階段 ( 出火源 ) Fire origin 4m 8m 8m 3m O 24m 注 Simple steel structure 15

16 4.Outline of full scale fire test (Preparatory test) 4/5 To prevent fire spread eaves Appearance Interior finish Gypsum board finish Partly noncombustible material column, beam and floor are wood finish improved installation of fire door to wall Exterior Wall To prevent upward fire spread Balcony and eaves Fire Wall Independent on building structurally 16

17 0min. 7min. 21min. 37min 50min. 4.Outline of full scale fire test (Preparatory test) 5/5 Ignition Smoke from the south opening of ignited room Smoke from the north opening of ignited room Smoke filled ignited room Reignition by torch Sorth side 131min. 139min. 142min. Flame from the opening of 2 nd story Fire spread to classroom of 3 rd story Extinguishing fire by safety reason 61min. 90min. Glass of 2 nd story classroom broke Flashover 420min. No collapse after test North side 13min. 129min. Flame from the north opening of ignited room Fire spread to classroom of 2 nd story through the floor Summary of result Prevented early fire spreads Prevented fire spread through fire wall. Prevented fire wall collapse 17

18 5. Conclusions 1/1 The full-scale fire test will be carried out based on specifications which hypothesize standardization in the fiscal 2013, with specifications and test method adjusted based on these results. The results of the three full-scale fire tests will be used for revision of BSL which ensure the fire safety that will be required of a wooden 3-story school building. 18

19 Thank you (in Japanese) These tests were carried out based on a joint research among Waseda Univ., Akita Prefectural Univ., Mitsui Home Ltd, Sumitomo Forestry, Gendai Keikaku Kenkyujo, Architects and Associates, Building Research Institute and NILIM. 19