What are the standard numbers of steps for an arc-shaped staircase?

The number of circular arc staircase steps is not fixed and depends on factors such as floor height, step size, and arc radius. It should be determined based on ergonomic principles and building regulations. The specific standards are as follows:

1. Core determination principles

- Adapt to floor height and step height: Number of steps = Floor height ÷ Single step height. The result should be an integer, and the single step height should be within the national standard range of 150mm - 180mm (for residences, it can be relaxed to 190mm).

- Balance walking comfort: The number of steps per stair section is recommended to be between 11 and 18. Too few (less than 8 steps) will result in excessively high step heights, while too many (more than 18 steps) will require additional rest platforms to avoid fatigue during walking.

2. Supplementary standards for different scenarios

- Residential areas (villas, duplexes): Floor height is usually 2.8m - 3.3m, corresponding to step numbers 15 - 22 (for a floor height of 3m, calculated at 160mm / step, approximately 19 steps). It can be designed in two stair sections (each section 9 - 11 steps), with a rest platform in the middle.

- Public areas (shopping malls, hotels): Floor height is mostly 3m - 4.5m. The number of steps per stair section should not exceed 18. If it does, it needs to be divided into sections. The total number is recommended to be 20 - 30 steps, suitable for efficient passage in crowded scenarios.

- Children / Elderly adaptation: The number of steps can be appropriately increased (for a floor height of 3m, calculated at 140mm / step, approximately 21 steps). The single step height can be reduced to improve safety, while avoiding overly long single stair sections.

3. Special requirements for circular arc characteristics

- Matching arc radius: The smaller the arc radius, the number of steps needs to be appropriately increased (for every 1m increase in radius, 2 - 3 steps can be reduced). Avoiding overly steep arcs that cause narrow steps, which will affect walking stability.

- Avoiding odd-numbered step deviations: It is recommended to prefer even-numbered steps to ensure balanced force distribution between the upper and lower stair sections, especially for double arc or rotating circular arc stairs, where even-numbered steps can reduce directional deviation during walking.