First, the fire characteristics of high-rise buildings and its harmfulness
(1) There are many ways to spread the fire, which is easy to form a three-dimensional fire. Because there are many elevator shafts, cable shafts and pipeline shafts in high-rise buildings, it is easy to form a "chimney" effect after a fire. The higher the building height, the more obvious the "chimney" effect, which is easy to cause smoke and fire to spread rapidly upward. At the same time, because there are many horizontal ventilation pipes, smoke and fire are easy to spread horizontally along the cracks, walkways and pipes of the ceiling. Therefore, once the high-rise building fire is out of control, it is easy to form a three-dimensional fire.
(2) It is difficult to evacuate people, and it is easy to cause mass casualties. High-rise buildings have complex structures, diverse functions and dense personnel. When a fire breaks out, on the one hand, due to the dense personnel and few or unfamiliar evacuation passages, high-temperature smoke fills the whole building when the internal personnel evacuate by themselves, so the visibility is low, and stampede and injury accidents often occur due to crowding, and some people even jump off a building because of panic. In addition, under normal circumstances, trapped people will be in danger of death if they stay in the thick smoke for 4-5 minutes, so high-rise building fires can easily lead to suffocation, poisoning and death, resulting in mass deaths and injuries.
(3) The fire load is large and it is easy to form a large-scale burning fire. High-rise buildings are various, including residential buildings, hotels, shopping malls and other complex buildings, with diverse functions and many combustible decorative materials. According to statistics, the fire load density of ordinary houses can reach 35-60kg/㎡, and that of high-class hotels can reach 45-60kg/㎡. Therefore, once a fire breaks out in a high-rise building, it is easy to form a large-scale fire in a short time.
(4) The height of the building is high and it is difficult to put out the fire. On the one hand, when a fire breaks out in a high-rise building, the stair-climbing vehicle often can't reach the height of the burning floor, and it mainly relies on indoor stairs or fire elevators to climb the building to put out the fire. Due to the high floor and many equipments, the physical strength of fire-fighting and rescue workers will be seriously reduced after climbing to a certain height, which will affect the fire-fighting and rescue operations to some extent; On the other hand, after the fire broke out, the whole high-rise building was generally blacked out, and the smoke produced during the fire was large, and the indoor visibility was reduced, which also seriously affected the fire fighting and rescue operations.
(5) The command is difficult and the sense of coordination is not strong. High-rise buildings are huge, and there are many dead ends in communication. In addition, the environment of the fire site is noisy, and the communication inside and outside the fire site is prone to poor communication, which often leads to the failure to convey the orders on the fire site in time and makes it difficult to conduct on-site command.
(six) there are more falling objects upstairs, which affect the fire fighting operation. When the high-rise building burns in a wide range and the fire is fierce, the lighting glass, billboards and air conditioning auxiliaries on the external wall and the internal flat roof will fall off due to the heat, especially when the glass falls, it will pierce the water pipe, endangering the safety of personnel and vehicle equipment. The "flying knife" produced in the process of fire fighting seriously threatens the "fighting action and process" of fire officers and soldiers.
Second, the high-rise building fire disposal and evacuation countermeasures
(1) Strengthen the mobilization of the first force.
When a fire breaks out in a high-rise building, the fire spreads quickly, and it is easy to form a three-dimensional combustion in a high space. Therefore, it is very important to strengthen the mobilization of the first mobilization force for fire protection in high-rise buildings. The author believes that the mobilization of the first mobilization force for high-rise building fires should be based on meeting the needs of controlling the development and spread of fires and adapting to three-dimensional operations, with the following factors as the key considerations:
1. Considering that high-rise building fires are prone to three-dimensional combustion, fire extinguishing mainly depends on the use of fixed fire-fighting facilities in high-rise buildings. The first batch of fire fighting vehicles mobilized by on-site forces should be mainly high-power, large-tonnage water tank guns and medium and high-pressure pump fire fighting vehicles.
2. Considering the need of evacuation and fire fighting in high-rise buildings, the first mobilization force should not only mobilize the duty squadron and ordinary duty squadron in the responsibility area, but also mobilize special squadrons and special vehicles such as climbing, smoke exhaust, lighting and emergency rescue to rush to the scene at one time.
3. Considering the complexity of high-rise building fire scene, the need of maintaining order and evacuation, we should mobilize public security, traffic police, water supply, power supply, medical care, ambulance and other social forces to arrive at the scene at the same time.
(2) Focus on personnel evacuation and rescue.
The rescue and evacuation of people in high-rise building fire is an important and arduous task. Firefighters must firmly establish the guiding ideology of "saving people first", evacuate and rescue in time, and avoid and reduce casualties. The following measures should be taken according to the specific situation on site: 1. Radio-guided evacuation High-rise buildings are generally equipped with accident broadcasting systems. When a fire breaks out, firefighters should use the broadcast system to guide the trapped people to evacuate the fire site in an orderly manner.
2, the use of evacuation stairs, fire elevators and other vertical evacuation to the ground. In the process of evacuation, evacuation stairs, evacuation bridges, indoor evacuation walkways and evacuation ladders are selected and used in turn. These evacuation equipment are safe and reliable, and the evacuation volume is large.
3. Horizontal evacuation of rooms, walkways and halls. Evacuate to the place where the evacuation stairs or refuge utensils are far away from the fire point, prevent trapped people from entering the bag-shaped walkway, and give priority to evacuating and guiding women, the elderly, children and the disabled to the balcony, evacuation stairs and refuge utensils.
4. Use rescue equipment for rescue and evacuation. Site conditions permit. In case of emergency, rescue equipment such as life-saving bag, life-saving ladder, life-saving air cushion and rope can be used to rescue and evacuate the trapped people.
(3) Give priority to the use of fixed fire-fighting facilities in high-rise buildings.
High-rise buildings are equipped with relatively perfect fixed fire-fighting facilities, which should be fully and effectively used in fire fighting.
1, fire control room, high-rise building fire control room is generally located in the basement, after a high-rise building fire, the first force to arrive at the scene should assign familiar operators to the fire control room, through the automatic fire alarm system in the control room, initially understand and master the location of the fire floor, and master whether the fixed fire control facilities can work normally.
2. Water pump adapter and outdoor fire hydrant. In order to meet the needs of fire water in high-rise buildings, according to the requirements of design specifications, a water pump adapter and an outdoor fire hydrant system are set up to ensure the fire water in case of fire.
3. Indoor fire hydrant system. The fire protection of high-rise buildings mainly depends on fixed fire protection facilities. After the fire pump is started, or after the fire truck is connected with the pump adapter to supply water to the indoor hydrant pipe network, firefighters can use the indoor hydrant system to directly extinguish the fire in layers to prevent spread, disperse smoke and cover evacuation.
4. Automatic spraying facilities. High-rise buildings are generally equipped with automatic sprinkler systems, especially in the refuge floor. Automatic sprinkler system is more demanding. According to the design requirements, when a fire occurs, the temperature reaches 60℃-70℃, and the automatic sprinkler system will automatically spray water to prevent the fire from spreading. According to the needs of fire, the automatic sprinkler system can also be manually operated on the upper or lower floors of the fire floor to meet the needs of preventing the fire from spreading.
(4) Fire command and communication
To put out fires in high-rise buildings, we must invest a lot of personnel and equipment, strengthen organization and command, establish a lean and efficient fire command and frontier command, and do a good job in coordinated operations of multiple arms and departments.
1. Set up a fire fighting headquarters with the participation of government, public security, fire fighting, armed police, garrison, water supply, power supply, sanitation, communications and other departments, and set up a two-story front headquarters below the fire floor, so as to know and collect the fire in time, adjust the deployment of troops according to the fire changes, and conduct random command.
2. Mobilize support forces in time. When there is a fire in a high-rise building, it is necessary to find out the fire situation accurately and timely, and mobilize support forces in time according to the changing reality. When the local strength is insufficient, report to the superior in time and ask for rescue support.
3. Organize capable personnel to do internal reconnaissance. If the internal situation of high-rise building fire is unknown and needs internal reconnaissance, organize capable personnel, wear personal protective equipment and go deep into the interior for reconnaissance. During reconnaissance, 2-3 people should make evacuation signs in groups, and cover them with water guns when necessary to ensure safety.
4. While discovering and collecting the fire, the frontline command should put forward the fire fighting and rescue plan in time and be a good staff member of the fire command.
5. Effectively strengthen security. It is difficult and dangerous to climb high buildings to save people and put out fires. Wear personal protective equipment to prevent poisoning, falling, smashing, electric shock and burns.
Fire communication should be based on three-level networking, wired, wireless, GIS and other systems. If necessary, contact signals can be agreed in advance, and manual contact can be made to ensure the needs of fire control communication.
Third, the conclusion
In a word, preventing and fighting high-rise building fires is still a difficult problem in today's fire fighting work. The fire control work of high-rise buildings under construction must follow the fire control policy of "prevention first, combination of prevention and elimination". According to the characteristics of high-rise buildings under construction, based on self-prevention and self-rescue, reliable fire-fighting measures are taken to achieve safety, applicability, advanced technology, economy and rationality, and prevent fires from the source, so as to nip in the bud.