What are the "four mouths" in building construction?

The "four openings" in building construction mainly refer to the stairs, elevator wellhead, reserved holes and access openings in building construction. The holes and boundaries formed in the construction process of the construction industry are major hidden dangers of accidents, which may cause accidents if you are not careful, and will inevitably leave various holes in the construction process. Therefore, reliable measures should be taken to protect these holes and create safe working conditions for construction personnel.

Extended data:

"Three treasures" refer to safety helmets, safety belts and safety nets.

"Four ports" refers to stairs, elevator wellheads, reserved holes and access ports.

"Five sides" refers to the balcony periphery without railings, the horizontal periphery without external frame protection, the floor periphery of frame engineering, both sides of the upper and lower runways and ramps, and one side of the unloading platform.