建築物外牆開口與鄰棟間隔距離對火災輻射延燒之影響

莊英吉

[中文摘要]

本研究係以全尺寸實體火災試驗，探討防火建築物之居室發生燃燒時，其經由外牆開口部產生之輻射熱，是否會對鄰棟建築物造成輻射引燃。試驗以兩層鋼筋混凝土造建築進行，各層樓有一居室（一樓：3.00m（高）×2.64m（寬）×3.64m（長），二樓：2.93m（高）×2.64m（寬）×3.64m（長）），各有一單開窗（外牆）及單開門（75㎝×180㎝，內側），一樓開窗條件為2.64m（寬）×1.72m（高）、1.72m（寬）×1.72m（高），二樓開窗尺寸為1.64m（寬）×1.64m（高）。依試驗結果顯示，各居室火災時，其開窗中央對向2m距離之輻射熱，均超過木質材料等可燃物引燃危險值（1w/cm2），顯示有棟間輻射延燒之虞。在相同開窗及居室條件下，居室門扇關閉時，火載量大小對輻射熱及輻射面積影響差異不大，但當居室門扇開啟時，火載量越大輻射面積及輻射熱也越大。而相同火載量門扇關閉時，較小開窗之輻射熱，大於較大開窗之輻射熱。最後經評估分析，本研究建議一般住居建築輻射面積以外牆開口面積代表，輻射放熱源以10.4w/㎝2計，來檢討棟間輻射延燒危險性。

[英文摘要]

By using full scale fire tests, this study discusses that if neighborhood will be ignited byng which is burning inside.　The experiments are conducted using two stories building of R. C, each story has a room (1F: 3.00 m(height)×2.64m(width)×3.64m( length), 2F: 2.93m (height)×2.64m(width)×3.64m(length)), each room has a window opening and a door(75㎝×180㎝). The window opening size of the first story is 2.64m（width)×1.72m（height)/1.72m（width)×1.72m(height) , and the window opening size of the second story is 1.64m（width）× 1.64 m （height）. The results show that the radiation of all cases exceed the unsafe value(1w/cm^2) of wooden material at the distance of 2m from the center of the window opening of fire room, and it means that the opposite buildings are danerous to be ignited by radi ation when the distance between buildings is 2m and above. In the condition of the same window opening size and room size, the fire load doesn't affect the　 radiation and the area of the inflicting radiation when the door of fire room is closed. But when the door of fire room is opened, greater fire load occurs greater radiation and the area of the inflicting radiation. And when the door of fire room is closed , the small opening size makes greater radiation than the larger one in the same fire load. Finally, by concluding the tests , this study probes into that the opposite buildings will be ignited by the radiation from the openings between buildings , and makes suggestions　for the residence that the area of the inflicting radiation is the window opening size of the external wall and its value of the inflicting radiation is 10.4 W/cm².