Driven by economic development and construction technology progress, commercial buildings are developing into complex buildings with complex functions, complex structures, rigorous organization and rich forms, covering retail and wholesale, catering and entertainment, parking and so on. The development of commercial buildings provides convenience and rich services for people's life and work, and improves people's quality of life. However, the large-scale and functionalization of commercial buildings lead to many internal divisions, complex paths and diversified exhibition projects, which brings serious fire hazards. According to the characteristics of commercial buildings, this paper analyzes the danger of fire and the important factors affecting fire evacuation, so as to provide help for the fire prevention and safe evacuation design of commercial buildings and ensure the safety of people's lives and property.
With the acceleration of urbanization, modern commercial buildings have the characteristics of large area, large public space, large building scale and wide parking lots. Often built in the city center, there is a large flow of people nearby. Many specialty stores, head stores, large shopping supermarkets and commercial corridors form a closed commercial aggregate, and its functional services cover catering, leisure and entertainment, shopping and tourism, financial culture and so on. Providing all-round quality services for people's lives has attracted many people to stop and stay. Therefore, it is necessary to reinforce commercial buildings.
First, the fire characteristics of commercial buildings
1. In order to increase passenger flow and turnover, the shopping mall has set up a variety of business scope, providing clothing, textiles, household appliances, furniture, household appliances and other commodities, and finely decorating the area or specialty store with floors and soft cloth. These flammable substances increase the risk of fire.
2. In order to attract people to stop and watch, merchants often use special display methods, or three-dimensionally arrange items or hanging items around walls or roofs, but similar display methods increase the air flowing in the space. When a fire breaks out, good ventilation provides a basis for the spread of the fire.
The rich functions of shopping malls attract a large number of people. Modern shopping malls provide escalator vertical transportation mode to facilitate the flow of customers. People's awareness of disaster prevention is reduced during shopping and leisure, and they do not pay attention to the distribution of safe passages, which increases the difficulty of escape. The concealment of large shopping malls and safety stairs leads to the blindness of people's escape in fire, which increases the degree of fire hazards.
Second, the main factors affecting the fire safety evacuation of commercial buildings
1, commercial buildings are complex and have a large space, which affects people's identification of their location. They need to rely on indicator signs to guide them, and they lack autonomous flow in case of fire. Some merchants are lucky about the fire, occupy the hawker passage without authorization, and expand the trading display interface without permission, which leads to the horizontal partition area not conforming to the fire prevention code, which leads to the poor operation of the fire prevention mechanism in shopping malls and increases the difficulty of evacuation.
2. Products and decoration materials sold in commercial buildings may emit toxic smoke and dust particles when burning in case of fire, leading to suffocation and respiratory tract burns, which reduces indoor visibility. The high temperature of the flame makes it difficult for people to judge their relative position and escape route, resulting in crowding and trampling accidents, which increases the difficulty of rescue.
3. The scale and effective signs of evacuation passages in commercial buildings, the fire resistance of building components, the location and quantity of evacuation exits, and the psychological quality of evacuees all affect the safe evacuation of people in buildings, which should be fully considered in the design of safe evacuation.
Three. Fire prevention and safe evacuation design of commercial buildings
1, code for fire protection design
The fire protection design of commercial buildings is an engineering behavior of special architectural design, and it needs to be designed and planned according to the fire protection design code before the construction to ensure that the fire protection design is reflected in the architectural design. Code for Fire Protection Design is a law and regulation to manage and guide the fire protection design of buildings. It is mandatory and a necessary fire protection design measure in commercial buildings. The construction unit needs to adopt a more suitable and scientific design scheme under the guidance of norms, combined with experience and lessons, and under the guidance of expert argumentation meeting to realize the design optimization of fire protection standards.
2. Fire prevention and evacuation design of commercial buildings
2. 1 Characteristics of safe evacuation
The main function of safe passage is to evacuate people effectively, but it should be organized according to the characteristics of commercial buildings, including functional streamline, cargo flow and car flow balance, and ensuring the smooth flow of safe passage is the focus of design. Safe evacuation is a one-way activity, which means that people in a fire site reach outdoor or other safe areas through evacuation walkways and stairwells, with strong evacuation purpose. The scale of safe passage is determined according to the activity characteristics and laws of building shopping malls, and its scale is determined by effective calculation formula or mathematical model based on smooth passage. The purpose of the safe passage determines that all people who enter the shopping mall through elevators, escalators or other passages are compressed into the safe passage to ensure the bearing capacity of the safe passage and the safe operation of the lighting system, and to ensure the safe and rapid passage of people.
2.2 fire partition with reasonable layout
Setting fire zones in commercial buildings can relatively limit the fire to a certain range, prevent other inflammable and explosive articles in the building from exploding under flashover, cause the fire to spread rapidly, increase the difficulty of fighting, and win valuable time for the effective evacuation of personnel and materials and the arrival of rescuers. The characteristics of commercial buildings determine that the division of fire protection zones is complex and cumbersome. It is necessary to ensure the mutual connection between fire zones and the openness of zone space. Designers need to consider factors such as free division, and at the same time, realize the optimal division of fire protection zones according to the specific situation inside the mall.
2.3 Settings of safety exits
Fire escape is to provide people with a safe escape route in case of fire, and evacuation stairs are the main position of fire escape design. The design of evacuation stairs needs to be safe and reliable, and the fire escape should be coordinated with the daily flow of people. The design of safety exits must be obvious, which will help people to accurately identify when a fire occurs and when visibility is low. In the design of fire escape, it is necessary to establish an effective mathematical model to simulate the specific numerical values of people flow and passenger flow, and design the specific width and landing area of stairs according to people's escape psychology and escape behavior rules, so as to ensure that a large number of panicked people will not be crowded and trampled when passing through. In the design of fire escape, attention should be paid to the layout of lighting system and smoke exhaust system, and independent power generation system should be adopted to realize the power supply of lighting system and smoke exhaust system in the safety staircase, so as to ensure emergency lighting and effective smoke exhaust for crowd evacuation when other power sources disappear in the shopping mall building.
2.4 Fire separation design of shops and pedestrian streets in commercial buildings
In order to realize the beauty and transparency of shops in commercial buildings, tempered glass is used as the partition wall between shops and pedestrian streets. Tempered glass is a compressive stress layer formed by strict heat treatment process, and its mechanical strength and thermal shock resistance are obviously higher than ordinary thick glass. When a fire breaks out in a commercial building, tempered glass can't effectively prevent heat from conducting to the back fire surface. Usually, the back fire surface will cause combustible combustion under the action of high temperature thermal radiation, which will lead to the spread of fire and increase the difficulty of fire extinguishing. In a building with a pedestrian street shop, the fire separation design of the shop needs to prevent the broken tempered glass and thermal radiation. According to the characteristics of the building structure, it is necessary to design an automatic sprinkler system near the tempered glass partition wall to ensure that the automatic sprinkler system can be started in time at high temperature after the fire, effectively spray water to realize the full coverage of the water film on the surface of tempered glass, effectively organize the temperature rise of the back fire surface and the fire-facing surface of tempered glass, and organize thermal radiation to ignite flammable and explosive articles in the nearby area, so as to form a small-scale fire isolation zone in the tempered glass protection area and strive for the evacuation of people in the store.
2.5 Design of smoke exhaust system
Ensure that the mechanical smoke exhaust system is installed in commercial buildings, and the amount of mechanical smoke exhaust is not less than the number and times in the fire protection design code. Increase the effective area of natural smoke exhaust port, and stipulate that sundries should not be piled up near the smoke exhaust port to ensure the smooth smoke exhaust system in case of fire. Maintain the smoke exhaust machinery regularly, start the test regularly, and set up an independent power supply system to ensure good operation in case of fire.
The renewal and change of commercial buildings determine that the design of fire prevention and safe evacuation should be constantly updated and changed. In the design, planning and design should be carried out according to the national fire protection code, combined with the structural characteristics and pedestrian flow characteristics of commercial buildings, and timely maintenance and inspection should be carried out in daily life to ensure that the design scheme can exert the maximum benefit in the fire and ensure the safety of people's property and life.
For more information about project/service/procurement bidding, and to improve the winning rate, please click on the bottom of official website Customer Service for free consultation:/#/? source=bdzd