Construction of steel structure fire plan
Construction of steel structure fire plan
First, we have to analyze the characteristics of steel construction fire. Steel construction beams, columns, roof trusses are built skeleton, its security is directly related to the security of the entire building construction, they mostly use the steel, the steel Although non-combustible material, but its fire resistance is poor, with the change of temperature , its mechanics index will change substantially, capacity and balance stability with temperature increases significantly reduced. Steel at temperatures up to 350 ℃, 500 ℃, 600 ℃, its strength parting reduced by 1 / 3,1 / 2,2 / 3, the internal stress of change can also occur under high temperature conditions, so steel bearing system problems , according to theoretical calculations, at full load, loss of balance stability steel critical temperature of 500 ℃, usually fire at temperatures around 800 ℃ -1000 ℃, at such a high temperature condition, no maintenance of steel soon plastic deformation occurs, it will probably ruin collapse within 15 minutes. September 11, 2002, New York World Trade Center collapses in terrorist attacks, resulting in more than 300 firefighters innocent lives. After the plane hit the building loaded with fuel to form a load-bearing steel cylinder building maintenance layer is damaged, in strong high temperature, steel cylinder bearing strength decreases rapidly, just 20 minutes after the construction of the world's most famous disappear in our faces. In 2003, China Chia Tai Food Factory steel plant in Qingdao catastrophic fire, the formation of a large area of the plant collapses, many workers buried raw flames; 1972 Tianjin stadium fire, causing the roof to collapse, forming a huge casualties. Many examples of these fires have exposed a fatal flaw in the construction of steel structure fire resistance exists is poor, which give us the majority of construction planners proposed a new topic, how do fire planning competence steel construction, so steel construction to better serve our economic development. Guangzhou Steel
How do fire planning competence steel construction it? I think that should do the following three aspects:
First, according to fire hazards and the importance of the construction material, reasonably concluded that the construction of fire rating. Because of its use of a variety of construction features and the importance of not the same, there are differences fire risk, when we plan to build in accordance with the requirements of the owners, according to "construction plan for fire protection" and "high-level civil construction planning for fire protection", concluded repair constructional fire risk, and then based on fire risk, conclude the construction of fire rating, for example, a 60-meter high building complex, based on "high regulation" which belongs to a class of high-rise construction, its fire resistance rating should be level, its beam column, the fire resistance of roof bearing member should leave no less than two hours, three hours, 1.5 hours, and if we are not properly approved planning fire rating, determine the fire resistance rating is too high or too low, it will form a planning mistakes, too high a waste, is too low, the formation of insecurity.
Second, planning to choose the appropriate fireproof maintenance method. At present China's steel mainly uses three maintenance method: spraying, cladding method, water spray cooling method, they are to undergo a certain amount of technical means to improve the fire resistance of steel structures. Specifically, spraying is in steel coated with a layer of fire retardant paint, forming a protective film, thereby improving the fire resistance of construction components, it has thick and thin of the points, not the same as the thickness of the coating does not limit its fire Like; cladding method is the use of brick, concrete, calcium silicate board and other materials will be wrapped in steel, thereby forming a protective layer, to improve the fire resistance of members; washout active cooling method is a spray system is disposed in the upper part of steel, in case of fire, Start spraying the steel surface to form a continuous film of water, to maintain the effect. We in the planning, construction should be based on the member is not the same fire resistance requirements, through scientific comparison, select the most appropriate method of fire maintenance, to economic and safety requirements.
Third, when the construction of the Guangzhou Steel Reflections staff to fully decentralized planning issues. Since the steel construction of the shortcomings of their own existence, we ponder when planning to fully staff the dispersion factor, the occupant density indicators and steel construction features together thinking, enhance road safety dispersion, dispersion distance, dispersion width of planning requirements, assurance personnel dispersion time is less than the fire resistance of construction components, make sure that when people can safely escape a fire, Qunsiqunshang avoid fire accidents. Guangzhou Steel
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