General construction fire fighting characteristics and safety precautions

(i) Classification and characteristics of civil buildings:

According to the nature of use

According to the material used in bearing structure

According to the fire rating of the building

The fire rating of a building is divided into four levels:

A fire rated building is a mixed structure of a reinforced concrete structure or a brick wall and a steel concrete structure;

Grade II fire-resistant building is a mixed structure consisting of steel structure truss, reinforced concrete column or brick wall;

The third-class fire-resistant grade building is a brick-wood structure composed of a wooden roof and a brick wall;

The Class 4 fire rating is a combustible structure consisting of a wooden roof and a hard-to-burn wall.

(II) Classification and Characteristics of Industrial Buildings

Industrial buildings are houses and buildings for production use. According to the types of industrial production and production requirements, their classification and characteristics are described as follows:

According to the use of industrial buildings;

According to the internal production status of the workshop;

According to the number of factory floors.

(iii) Development and spread of fires in general buildings

General building fire development process:

The initial stage of the fire

Burning stage

Attenuation extinguishing stage

(4) Characteristics of Fire Spread in General Buildings

1 , the spread of the fire in the room

2. Corridors and stairwells spread fire

3 , the top fire spread

4 , stuffy top fire spread

Second, the characteristics of general building structure collapse collapse:

(1) The reasons for the collapse of the general building structure:

High temperature causes

explosion

Additional load

Firefighting

(2) The law of the collapse of the general building structure:

The sequence of collapse of the structure is generally from top to bottom, the roof of the ceiling is suspended first, and the pillar is the last.

(iii) Premature collapse of general building structure:

Excessive deformation

Abnormal sound

III. Harmfulness of fire smoke in general construction

The so-called smoke refers to solid or liquid particles floating in the air and a gas mixture produced when the material is heat-sealed or burned. Combustibles, such as building materials and building materials, are separated by heat during fire and then reacted with the oxygen in the air to produce various products such as carbon monoxide, carbon dioxide, sulfurous acid, hydrogen halides, and hydrocarbons, and fire smoke. It will cause serious harm. The hazards are mainly toxic, light-reducing and terrorist. The danger of fire smoke can be summarized as two aspects: physical and psychological harm to people. The toxicity and light-reducing properties of smoke are physiological hazards, while terror is a physical hazard.

(a) The toxicities of fire smoke are mainly manifested in three aspects:

1 , lack of oxygen

In the event of a fire, the oxygen content in the smoke is often lower than the value required for normal physiological conditions. When the oxygen content in the air drops to 15% , the human muscle activity declines to 10% - 14% . weakness, mental confusion, disoriented; to 6% - while 10% of people fainted, the oxygen concentration of less than 6% in a short time, people will hypoxia suffocation. In the event of a fire, the minimum oxygen content can reach 3% .

2 , poisoning

Smoke contains a variety of toxic gases, and the content of these gases has exceeded the minimum allowed by people's physiological normal, causing people to die of poisoning.

3 , high temperature

Fire smoke has a high temperature, which is also a great hazard to people. In a burning room, the temperature of flue gas is up to several hundred times. In underground buildings, the temperature of fire smoke can reach as high as 1000 °C .

(II) Light-reducing properties of fire smoke:

In the event of a fire, the smoke contains more smoke particles that are opaque to visible light and completely obscured by visible light. When the smoke is diffused, the visible light is greatly attenuated by the smoke particles and the visibility is greatly reduced. It is the light reduction of smoke. At the same time, toxic gases in the flue gas can be extremely irritating to human eyes, leaving people unable to open their eyes. As a result, visibility can be reduced and the fire can be inconvenient.

(c) The terror of fire smoke

Fourth, general construction fire fighting measures

(I) Main attack, secondary attack

When fighting fires in general buildings, you should try to play close combat within the building and deploy the main force to directly eliminate the fire. The main way to attack is the stairwell corridor inside the building and the outer balcony and so on.

(b) Preventing the vertical spread of fire

1. When deploying fires in multi-storey building fires, it is necessary to deploy power mainly at the combustion floor to eliminate fire extinguishing power. At the same time, deploy power at the upper floors that are more threatened by fire, and block the spread of fire from the floor to the upper floor, and pay attention to the air structure. The vertical development of the fire, if necessary, to carry out the demolition, water firefighting, the lower layer of the combustion layer should also deploy forces, responsible for monitoring and checking the fire, in the event of high temperatures and flames, they should immediately cool or eliminate the flame, to prevent the fire from the ignition layer The lower layer spreads;

2. For the up and down spread caused by the heat conduction of the metal pipe, it is necessary to organize the strength to check and eliminate the burning at the upper and lower layers of the combustion layer at any time;

3. When the pyrotechnics threatens to climb from the window to the next level, the water gun positions should be set in time to shoot water at the windows to prevent the fire from spreading upward.

(iii) Measures to fight a boring fire

1. In a unilateral and boring fire, the force should be deployed in the direction of the spreading of the fire to block the fire;

2. When the fire is not burned through the room cover and ceiling, it should be based on internal attack, water gun water into the stuffy way, usually from the ceiling or broken ceiling offensive, but also from the outside through the skylight, demolished housing cover and other methods Enter the boring fire. When taking an outside attack, the lower ceiling should be set to prevent the spread of fire.

3. After the fire has burned through the roof, it should be fired at the same time with the necessary external attack.

(4) Fire-fighting measures for simultaneous combustion of multi-storey buildings

1. When multiple layers are combusted at the same time, and the top has not yet been burned, the fire should be blocked and fire should be eliminated by deploying layers of fire from top to bottom.

2. If all the top layers have been burned, deploy force blocking at the lower part of the combustion layer to prevent the fire from spreading to the lower layer, and then deploy the power to extinguish the fire at multiple layers of the fire.

V. Fire precautions

Measures should be taken in time to reduce the threat of high-temperature smoke to firefighters and trapped people;

For personnel at the front of fire extinguishing and entering the combustion zone, personal protection must be provided;

When fire doors and windows are opened, people need to stand on both sides of the door and window to cool the water first to avoid the high-temperature air jet from indoor deflagration and hurt people.

For in-depth construction attacks, especially when entering a boring fire, the following points should be noted:

1 ) Be cautious about roof operations to prevent slipping and hurting people;

2 ) When it is broken, there must be protection;

3 ) There is frost in cold winters, and protective measures should be taken to prevent them from falling off;

4 ) It is necessary to pay attention to changing the jet status in time to reduce water loss.

Sixth, general building fire fighting technology

(a) Fire Scouting

1. Is there any person in the building surrounded by fireworks? Are the number of trapped persons, their location, and the access to these areas open or not, and whether they need to be demolished?

2. The direction of the fire in the area of ​​the fire, the possibility of the spread of fire in the hollow area along the hollow structure, and the identification of the situation where the upper and lower floors of the fire site and adjacent rooms are threatened by fire;

3. Find out the characteristics of the building structure and infer whether there is a danger of collapse according to the burning time of the components;

4. Find out the ventilation status of the building, whether there are firewalls, tiger windows, and stuffy entrances.

(B), the fire rescue

1. self-help;

2. Use vehicle equipment to save people.

(c) Selecting appropriate fire fighting positions

1 , the choice of water gun positions

( 1 ) Positions for water guns are forbidden to be placed in the position where the doors and windows are facing and above or below the light roof, sunshade, rain ponton. When it is necessary to implement the demolition and interception from above, it is necessary to use fire ladders to be erected on the load-bearing walls and to protect them. The combat personnel must not leave the fire-fighting ladder (the roof operation is recommended to use a horizontal bar ladder on the roof and link with the ladder; Workers work on the horizontal bar ladder and make fixed links.

( 2 ) rely on bearing walls;

( 3 ) Use fire ladders. When the fire layer is more than two layers;

( 4 ) Use topographical features.

2 , the position of the water separator

In the position of ground attack, the water separator is usually set on the side of the windward direction and the spread of the fire direction; or the middle part of the two water guns, when the water gun needs to be on the roof, it is located near the fire ladder;

When the floor is offensive, the water separator is usually installed in the stairwell near the combustion floor; if several floors are burned at the same time and they are responsible for the lower-level offensive mission, the water separator can be located in the lower stairwell; it is responsible for the upper-level interception mission. In the combat class, the water separator is installed in the upper stairwell.

(D), fire demolition

1 , the significance of the demolition:

The demolition of fire sites refers to the firefighters' use of fire extinguishing agents to complete the detection of hidden sources of fire, rescue people and evacuation of substances, prevent the spread of fire, remove dangerous situations, change the spread of fire and the direction of smoke flow, approach fire sources, and enter buildings. Each combat mission carries out partial or total demolition of buildings and their components or other objects.

2 , breaking method

In the fight against fire, when carrying out a demolition operation, it is necessary to use different methods depending on the target; the main methods include the deterrence method, pull-out method, cut-and-expand method, collision method, and blasting method.

The information in this article comes from the Internet and was reorganized and edited by China Rescue Equipment Network.