What are the main disaster causing factors studied by fire door manufacturers

Radiation and substances will cause long-term pollution to the environment, cause serious damage to buildings and structures exposed to the ground, and cause fatal casualties, which can lead to a series of other natural disasters, such as fire, tsunami, river burst and dam break, forming barrier lake, causing mountain flood and debris flow, causing soil liquid, causing new geological disasters, etc. The fire door manufacturers mainly study the direct disaster, including the damage to the foundation and structure of buildings and structures. The damage to the structure is transmitted around in the form of vertical and horizontal waves. The influence range of vertical wave is small, but the damage is small; the influence range of horizontal wave is small, but the damage is relatively small. The response acceleration of load to buildings and structures is the main external force that destroys buildings and structures, and the duration of load is also the main failure factor ①. The destruction of buildings in the epicenter is mainly vertical shear failure, and the influence of areas outside the epicenter on buildings is mainly horizontal shaking. If the horizontal force of load affects the lateral displacement resistance of buildings, buildings will undergo shear failure.

When the duration of the load is long, although the dynamic load does not reach the limit load level of building anti lateral displacement, after the continuous action of the load, it will cause fatigue failure of building anti lateral displacement structure and eventually lead to structural failure. The damage to the foundation is mainly soil liquid. Soil fluid usually occurs in loose, cohesionless saturated soil. At this time, the gap between coarse-grained soil is completely filled with water, and the water has a pressure on the surrounding soil particles, which determines the purple density of compression between soil particles. The water pressure of the fire door manufacturer is relatively low before the fire. However, it will cause the water pressure to rise until the soil particles can move each other. When the ground movement and soil shear strength decrease to zero, the pore water pressure of the soil suddenly decreases, the strength of the soil decreases, the support capacity of the soil decreases, and the structure bearing on the liquid soil will suffer relatively large displacement, so the foundation of buildings will be displaced with the movement of the supporting soil. In this process, the building foundation may be damaged, resulting in the overall damage of the building propagating in the form of wave. When the wave is transmitted from the bedrock to the ground, the soil medium will move under the action of wave, usually release, and transmit the motion to the underground engineering structure at the same time.

Under the action of, the dynamic response of underground engineering structures can be divided into two categories: foundation failure and foundation vibration and deformation. It is generally believed that the main factor that the fire door manufacturer plays a role in the dynamic response of underground engineering structure is the vibration and deformation of foundation, and the disaster reason of wind disaster is that the wind load is caused by air flow. There are two main damage modes: ① other damage types induced by wind, such as waterlogging caused by typhoon carrying rainstorm in the typhoon path, flood caused by typhoon exposing waves in coastal areas, etc; ② Wind load directly causes disasters, such as the wind pressure damage of typhoon and tornado to buildings and structures, and the impact damage of wind carrying debris to buildings and structures. The damage of other disasters caused by wind disasters, such as water load damage, will be described in detail in this section. Direct disaster caused by wind load is the focus of this section. The damage mechanism of wind load on buildings. Wind load includes average wind and fluctuating wind. The wind force is small and varies with time. The damage of wind load mainly depends on the small wind pressure and the stress and stability of the structure of the building itself.