1001頁:A014 消防建筑施工:建筑基本常識

發布時間:2019-07-23點擊量:506

建筑消防常識A14

圖片內容

My client thanks you for saving his life. However, your well educated, split second, heroic actions caused him under discomfort and harm-Thus...

我的客戶感謝你能救他一命。但是,你神乎其技、神勇無敵、神兵天降般的行動傷害到了他,并使他感到不適。因此~~

Lawsuit

訴訟

雙語:

Dead Loads

恒荷載

Dead load is the weight of the building itself and any equipment permanently attached to it or built in.

恒荷載是建筑物自身重量和永久附加其上以及內建的物體重量總和。

A more accurate term is self-weight. Years ago, dead load was often piled on the building without regard for the consequences.

更準確地說—自重。以前人們總是在建筑物上不斷增加恒荷載,但從不考慮可能的后果。

The modern designer more clearly understands that dead weight breeds dead weight.

當代設計師更清楚,恒荷載需要恒荷載來支撐。

Consequently, efforts are now made to lighten all parts of a building.

因此,現在所有的建筑構件都在向輕量化發展。

Removing a pound of dead weight at the top of a building enables the builder to reduce ounces at many points in the supporting structure.

在最高點拿掉一磅恒荷載,下面很多支撐結構均可減重幾盎司。

As proof of the criticality of this consideration, advertisements for building materials such as gypsum shaft liners now emphasize their weight saving over the traditional masonry enclosures.

例子比較極端,但證據比比皆是,像石膏襯板這樣的建筑材料在打廣告時就會強調其比傳統磚砌圍墻更加輕盈。

Today, buildings can be considered as being bought by the pound.

今天的建筑幾乎可以“按斤賣”了。

Fire resistance is closely related to mass.

防火性能與重量密切相關。

All other things being equal, a heavier steel beam will take longer to fail due to heating than a lighter beam.

若其他條件相同,更重的鋼梁受熱后的坍塌時間點要晚于輕質鋼梁。

A 4- by 10-inch (102- by 254mm) wooden beam will support its load longer while burning than will a 2- by 10-inch (51- by 254-mm) beam.

4*10英寸(102*254毫米)的木梁在燃燒狀態下比2*10英寸(51*254毫米)堅持更久。

This point highlights a valid general principle: Any substitute structural element that is of less mass than the element previously used to carry an equivalent load is inherently less fire resistant.

這點告訴我們一個常理:承載相同的荷載,更輕的構件防火性能較差。

Added Dead Loads

額外的恒荷載

A structures dead load is often increased during alteration of a building.

建筑在改建過程中,通常都會增加恒荷載。

For example, the addition of air conditioners to the roof of a building previously without air conditioning may mean that its dead load is increased without any strengthening of the structure.

例如,給沒有空調的建筑添置空調可能意味著在沒有增強結構強度的前提下增加了建筑的恒荷載。

At one fire in a large city, fire fighters were overhauling a fire in a restaurant, seeking out hidden pockets of fire in the overhead.

在某市一場餐館火災中,消防員在天花板夾層中搜尋火點。

They attacked the fire-weakened supports of the building. Above them, added-on air-conditioning units fell, causing several fatalities.

他們戳到了已經被大火削弱的支撐構件,隨后屋頂上后裝的空調機掉落,導致數人殉職。

Even when a structure is strengthened to cope with the added load, the modifications may not prove adequate to avoid collapse in a fire.

即使為應對荷載增加而加固過的構件,也有可能在火災中發生坍塌。

For instance, if lightweight trusses are strengthened by additional trusses, there is no improvement to resistance from fire collapse because all the trusses will burn and lose strength at the same time.

例如,輕質(木)桁架即便經過結構加固,但因為沒有針對性提高防火性能,火災仍能導致其燃燒并坍塌。

In one case, a supermarket was converted to a Japanese restaurant with many grills.

有這么個案例,一家日料店由超市改建而成,內部增設了很多烤爐。

Each grill required a heavy fume hood. These hoods were hung from the roof.

每個烤爐都設置了一個集煙罩,直接掛在天花板下。

When the building was a supermarket, the roof did not have to support such a dead load. Now the same roof must carry the hoodsand safety has been greatly reduced.

之前的超市天花板并不需要承受這些恒荷載,但現在多了這么多罩子以后,安全性必然大大降低。

Dead loads can be deadlyespecially dead loads for which the building has not been designed.

那些設計之初并未計入的恒荷載尤為致命。

It is critical that your local building department be notified and that a structural engineer assess the situation when you suspect a dead load is a catastrophe waiting to happen or you see dead loads on a building.

當你看到或感到某些建筑上附加的恒荷載可能會產生災難性后果時,請務必通知當地的建筑部門并請結構工程師對這些問題進行評估。

往期內容:

第一章 序言

1001頁:A001 消防建筑施工

1001頁:A002 消防建筑施工

1001頁:A003 消防建筑施工

1001頁:A004 消防建筑施工

1001頁:A005 消防建筑施工

1001頁:A006 消防建筑施工

1001頁:A007 消防建筑施工

1001頁:A008 消防建筑施工

1001頁:A009 消防建筑施工

1001頁:A010 消防建筑施工

第二章 建筑基本常識

1001頁:A011 消防建筑施工:建筑基本常識

1001頁:A012 消防建筑施工:建筑基本常識

1001頁:A012 消防建筑施工:建筑基本常識


來源:52號消防站
分享
QQ
二維碼
電話
91街机捕鱼外挂 西甲直播360 四川时时走势图结果 天津快乐十分20选8走势图 体彩三今天的试机号一 迪士尼极速时时 免费时时彩计划网 奥彩足球比分比 3d两码合最准破解 胜负让分大小什么意思 东方6十1走势图2元网 辽宁快乐12投注下载 七星彩历史开奖2000期 六肖中特054期 陕西快乐10分选号技巧 开门彩重庆时时彩 十三水怎么玩图解