How to describe the hotel staircase structure?

The number of steps shall not exceed 18 and shall not be less than 3.

Stairs are formally divided into straight ladders, arc ladders and spiral ladders. There are all-wood stairs, all-steel stairs, steel-wood stairs, iron-wood stairs, steel-glass stairs, marble stairs and so on. The straight ladder is the most common and simple, with geometric lines, strong sense of direction and a platform in the middle. The I-shaped straight ladder is the most convenient and unobstructed to walk, but it also occupies the largest space area; The arc ladder connects the upstairs and downstairs through curves, which can be changed into various shapes according to the space. There is no rigid corner of the straight ladder, which is beautiful in appearance and comfortable to walk, but it covers a large area. Spiral stairs occupy the least space, and the spiral curve is beautiful and moving, but it is not convenient for the elderly and children to carry things up and down.

In architecture, it is used as a component of vertical traffic between floors. Used for traffic contact between floors and when the height difference is large. Multi-storey and high-rise buildings with elevators and escalators as the main vertical means of transportation should also be equipped with stairs. Although elevators are the main vertical means of transportation in high-rise buildings, stairs should still be reserved for escape in case of fire. Stairs are composed of continuous steps (also known as ladder running), platforms (rest platforms) and enclosure components. The horizontal projection distance between the lowest and highest steps of stairs is the length of steps, and the total height of steps is the height of steps. During the Warring States period, stairs have been carved in the images of heavy houses on Chinese bronzes. 15 ~16th century Italy liberated the indoor staircase from the traditional closed space and made it a part of the building with various shapes and decorations.