【 Weak current College 】 skyscraper fire characteristics and fire protection design and security management-Power By 【 China power house network 】

Fire characteristics of tall buildings
(A) the fire spread quickly. High-rise building stairs, elevator shaft, pipes and ducts, cable, wells, vertical wells road, if not good fireproofing treatment, there is a fire as if there were some tall smokestacks, as the fire spread rapidly, particularly senior hotel, integrated building and library, Office building, skyscraper, General indoor fuel more, once the fire, burning fiercely, and spread rapidly. As far as determination of the early stages of the fire, because air convection in horizontal flue gas diffusion speed 0.3 metres per second, at the stage of the fire burning fiercely, the tube well smoke diffusion speed is up to 3 to 4 metres per second. If a height is 100. M tall buildings in case of fire, in the case of non-stop, half a minute or so, the flue gas can spread along the vertical tube well to the top level, their proliferation speed is 10 times the horizontal direction.

(2) evacuation difficult. The characteristics of high rise building: first floor, the vertical distance is long. Evacuation to the ground or other safe place; the second is the focus; the third is when the disaster occurred due to the vertical air flow unimpeded, the spread of fire and smoke up faster. Increase the difficulty of the evacuation, some economically developed City Fire Department handling stolen goods being a small amount of a fire engine, but most have a tall building cities do not yet have a fire engine, but it also does not meet the security needs of evacuation and rescue. General elevator in a fire because they do not prevent Fireworks or a power outage, etc. Therefore, the majority of high-rise building evacuation mainly rely on the stairs. The stairway once cuanru smoke, would seriously affect the evacuation. These are high building fires the adverse conditions for evacuation.

(Iii) it is difficult to fight. High-rise buildings up to tens of meters. Even hundreds of metres, when the fire broke out from outdoor to fight very difficult. General should be based on the self, i.e. mainly rely on indoor fire fighting facilities. But because at present, China's economic and technological conditions, high-rise building internal fire facilities also not may be perfect, especially in the second category of high-rise buildings are still fighting a fire hydrant system. Therefore, the Suppression of the Highrise often have greater difficulties. For example: heat radiation is strong, the spread of speed, skyscraper fire water shortage etc.

United States has occurred more than 7000 high-rise building fire. Nearly 20 per day. But the United States city high-rise building State-of-the-art fire management levels significantly reduces losses.

9 February night CCTV new subsidiary Cultural Center building fire. Beijing city fire station published messages that result in the direct cause of the fire was in the vicinity of illegal discharge fireworks. Another important reason is that in the construction phase of CCTV with floor has not yet opened fire prevention system, lack of self-help measures on site.

Due to the high-rise building fire danger, fire, the rapid spread of fire, evacuation difficult, difficult, and fighting on the fire safety design of tall buildings and strict safety management.

Legal regulation of fire safety design of tall building

In the national legislation of the high-rise building fire, regardless of the number of laws and regulations or maturity level, the highest number of high-rise buildings in the United States are going in the world. United States fire regulations of high-rise buildings, built on a large number of authority on the basis of the study. As early as the 1970s, in the United States National Science Foundation funding, Harvard is the father of fire science research that Howard · Armon, Professor, after a large number of experiments, the establishment of a widely-recognized Harvard fire model. In this model, based on the United States fire regulations more high-rise buildings, a model for many countries.

China's existing high-rise fire safety norms is a commandment of the 1995 tall buildings fire code (GB50045-95), the provisions of the specification, meticulous in fire resistance rating, layout, evacuation, fire water, anti (row) smoke and electric has strict requirements. But in practice, to take into account the reasonableness of fire security and investment. Fire safety design of tall building sometimes up to specification requires that a security breach. In recent years. Construction site of frequent fires, large amounts of insulation waterproof flammable materials accumulation and exposed, but also because of the tall building its own fire facilities not yet perfect. Some experts say that there was a need to develop, as soon as possible through amendments to the building site of the fire management specification, fill in the blank building fire safety weak, radically reduce the construction site in fire-prone.

Fire safety design is the umbrella

For high-rise building fire characteristics, both at home and abroad in the fire protection design and reached a consensus on. — So, you want to do the following four aspects of fire safety design.

The first. Ensure that the main structure has sufficient fire resistance stability. At home and abroad the tall buildings more dependent on the steel structure, although its integrity and stability are very good, but the fire resistance performance is poor. Steel tension and load-bearing properties are due to the increase in temperature and a sharp decline, usually 450-650 degrees Celsius will lose its carrying capacity, deformation, steel, steel beam bending, cannot continue to use. In General, not unprotected fire resistance of steel structure for only 15 minutes. "9 · 11" event in the United States New York World Trade Center collapse is due to the high-temperature steel structure by fire scorched. Superstructure of unstable down collapse, a collapsed to the end result. People widespread application in practice of the steel structure protection methods, such as refractory coating, spray coating asbestos or fireproof materials. Has been proven effective in responding to the fire, the building industry and the fire community in solving this problem is still a long way to go.

Secondly, strengthening self-help facilities. High-rise building is different from the typical low-rise, fire, high-rise buildings rely primarily on their own fire-fighting measures to guarantee security. Fire Department ladders can height is less than 100 m; if several hundred-metre tall buildings in a fire, it is difficult to rely on external forces rescue. Currently, high-rise building of self-help measures are divided into active and passive. Proactive measures directly restrict the fire and the development of technologies, such as a fire detection and alarm, sprinkler, fire suppression technology, smoke control technology; passive measures means improvingOr enhanced building components or materials withstand fire destroying the ability of technology, such as enhanced fire performance of building elements. These sophisticated self-help measures, than a large number of firefighters can better cope with the emergency fire. Third, do a fire separation. Because the building use functionality, scale shape, location and indoor fire load, decoration and furnishings, etc., building fire codes cannot be brought to a wide range of high-rise building fire safety requirements are detailed. This requires the designers for design of building concrete conditions. Flexible use, strengthen the fire cut off, increased fire extinguishing means to strengthen the measures for smoke control, using different solutions. Meet fire safety purposes.

From domestic and international fire statistics show that nearly 60% of fire deaths are smoked, or smoke after the burning Halo. Science of fireproofing design can effectively address this problem. For example, in the event of fire, fire stairs, elevator if you can maintain a higher pressure. Escape to open the door to enter, the wind will be blowing from inside to outside, the smoke away.

Fourth, the selection of flame-retarding material interior decoration. In architecture it is impossible to eliminate the source of fire, but the use of flame-retarding decoration is possible, is to avoid and reduce fire injuries and property damage of important measures.

Strict fire management essential

If fire safety design of tall building focuses on response from the hardware side, the fire hazard, strict fire management is from software to reduce fire losses. Unfortunately, high floor becomes, people tend to ignore this management role.

United States has occurred more than 7000 high-rise building fire, nearly 20 per day, but the United States city high-rise building State-of-the-art fire management levels significantly reduces losses. "9 · 11," the United States high-rise fire safety awareness and further strengthen the management of refinement to the indoor ash-bin design, at the request of property managers in scrubbing ash bin before to make sure that the drums have no fire.

In addition, the United States also the full mobilization of all sectors of society, such as the obligation for the town inhabitants. fire brigade Now, New York, and other large cities have set up automatic fire safety electronic access, phone, computer, mobile phone, and city fire brigade building obligations. In the event of danger, the city's residents, professionally trained volunteer fire brigade can be brought together in minutes, with fire fighting and rescue.