6.8.2 When there are handrails on one side, the clear width of the bench shall be the horizontal distance from the decorative surface of the wall to the center line of the handrails; When there are handrails on both sides, the clear width of the bench should be the horizontal distance between the center lines of the handrails on both sides. When there is a protrusion, the clear width of the step should be calculated from the surface of the protrusion.
Note: This article makes it clear that when there are handrails on one side of stairs, the structural thickness of wall decoration should be deducted from the net width of stairs. In addition, when there are frame columns or other components, settings, etc. Staircase protruding (except the protruding of the four corners of the stairwell), which affects the width of peers, the net width of the stairwell shall be calculated from the protruding part. When a barrier-free lifting platform is attached to the stairs, the clear width of the stairs should be calculated from the outermost edge of the folded lifting platform.
6.8.3 In addition to the current national standard "Code for Fire Protection Design of Buildings" (GB 500 16) and the current national design standards for special buildings, the daily clear width of stairs for main traffic should be determined according to the use characteristics of buildings and the number of people with a width of 0.55+(0~0. 15)m per person, and should not be less than 2 people. (0~0. 15)m is the swing of human body when people are exercising, and the upper limit should be taken in crowded places in public buildings.
Note: the minimum clear width of stair tread should be determined according to the comprehensive factors such as use requirements, modulus standards and fire protection standards. In the fire protection standard, the clear width of stair steps is 0.55m for each pedestrian flow, and the minimum width of two pedestrian flows should not be less than 1. 10 m, which is suitable for evacuation stairs, but it is not sufficient for other stairs that are usually used as daily main traffic, especially the main stairs of public buildings (such as shopping malls, theaters, gymnasiums, etc.). ) with closed personnel, so we should consider multi-person traffic to avoid congestion and congestion when dealing with traffic. In addition, the width of people flow is the minimum value calculated by 0.55m, in fact, the human body has a certain swing when moving, and there is a gap between them. Therefore, this article stipulates that the width of each pedestrian flow is 0.55 m+(0 ~ 0. 15) m, and the width of a single stair section needs to be appropriately increased.
In the standardized design of civil air defense stairs, the clear width of stair steps is 1 100~ 1400, which is in good coordination with civil air defense doors with widths of 1200 and 1300.
6.8.4 When the steps change direction, the minimum width of the platform at the turning end of the handrail should not be less than the clear width of the steps, and should not be less than1.2m. When it is necessary to carry large objects, it should be widened appropriately. The width of the middle platform of the straight staircase should not be less than 0.9m
Note: the width of the landing refers to the horizontal distance between the decorative surface of the wall and the center of the handrail. When there are protrusions or other obstacles that affect the width of the passage on the landing, the width of the landing should be calculated from the outer edge of the protrusions or other obstacles. When the height between the bottom of the frame beam and the ground of the stair platform is less than 2.00m, if the platform railing (plate) is set flush with the inside of the frame beam, the net width of the stair platform should be calculated from the inside of the railing (plate).
This article stipulates that when the stairs change direction, the minimum width of the platform at the turning end of the handrail should not be less than the clear width of the stairs, and should not be less than1.20m m. At the same time, the requirements of different types of construction teams should be considered to meet the minimum width of the platform to maintain the consistency of evacuation width. When it is necessary to carry large items, it should be widened appropriately so that large items such as furniture can pass through.
In the standardized design of civil air defense stairs, the platform width is calculated as ladder width +0.05. 1020, 1220, 1320 and 1520 correspond to the platform widths: 1.25, 1.35 and1.420 respectively.
The minimum width of the platform at the turning end of the handrail bisecting parallel stairs should not be less than the calculated minimum clear width of this section of stairs and should not be less than1.20m..
The middle platform of straight stairs is mainly used for people to rest on the way, which does not affect the evacuation width, so it is not required to be consistent with the clear width of stairs, but 0.90m is the minimum width. In actual design, the width of the intermediate platform should be reasonably determined according to the building type, and conform to the relevant provisions of special building design standards.
6.8.5 The number of steps per flight shall not be less than 3 and shall not exceed 18.
6.8.6 The clear height of the upper and lower aisles of the stair platform shall not be less than 2.0m, and the clear height of the steps shall not be less than 2.2m. ..
Note: The clear height of the step is the vertical height between the lower edges of the protrusions above the front edge of the step (including the range of 0.3m outside the front edge line of the lowest and highest steps of each step).
Note: The clear height mentioned in this article refers to the calculation from the decorative surface of the landing, steps and other parts to the lower edge of the brick decorative surface of the upper protruding part.
Due to the vertical treatment of buildings and the change of staircase practice. The clear height of the upper and lower parts of the landing is not necessarily the same as that of each floor, and the clear height at this time should not be less than 2.00m m. Make people not see each other in March. Generally speaking, the clear height of the stairs should be limited to the person's straight arm. When hovering upward on the stairs, the finger just touches the point on the lower edge of the upper protrusion. In order to ensure that people will not encounter and feel depressed when traveling, the clear height of stairs should not be less than 2.20m according to the common slope of stairs. Non-public staircases and maintenance staircases in indoor spaces such as houses can be appropriately relaxed when conditions do not permit.
6.8.7 Stairs shall be provided with handrails on at least one side. When the clear width of stairs reaches three people, handrails shall be provided on both sides. When it reaches four people, middle handrails shall be added. (Civil air defense stairs are generally 1 100, 1200, 1300, 1500, all of which are less than the width of three people, and one side can be provided with handrails. )
6.8.8 The height of indoor stair handrails from the front edge of steps should not be less than 0.9m. When the length of stair horizontal railing or railing plate is more than 0.5m, its height should not be less than1.06m.
6.8.9 In nurseries, kindergartens, primary and secondary schools and other special places for children's activities, when the clear width of stairwells is greater than 0.2m, measures must be taken to prevent children from falling.
Description: Why the space formed by stair section and platform is stairwell. In order to protect children's lives, the stairwell width of children's special activity places such as primary and secondary schools and kindergartens is more than 0.20m (the thickness of children's chest and back), and measures must be taken to prevent children from degenerating. Prevent him from playing slide games on the handrail of the stairs, causing a fall accident and falling to the bottom of the stairs. Stair railings should be made of structures and ornamentation that are not easy to climb, and the clear distance of the hollowed-out part of the railing or ornamentation should not be greater than 0.11m. Stair handrails should be equipped with facilities to prevent children from slipping. Reference should be made to other public places where children have frequent activities.
(The clear width of civil air defense standard stairwell is designed to be 0. 15m)
6.8. 10 The width and height of stair tread shall comply with the provisions in Table 6.8. 10.
The minimum width and maximum height of public stairs of residential stairs are 0.26 and 0. 175 respectively.
The minimum width and maximum height of stairs in residential suites are 0.22 and 0.200 respectively.
The minimum width of dormitory staircase in primary school dormitory is 0.26, and the maximum height is 0. 15.
The minimum width of stairs in other dormitories is 0.27 and the maximum height is 0. 165.
The minimum width of stairs in residential buildings for the elderly is 0.300, and the maximum height is 0. 150.
The minimum width of stairs in public buildings is 0.320 and the maximum height is 0. 130.
The minimum width of stairs in nurseries and kindergartens is 0.26 and the maximum height is 0. 130.
The minimum width of stairs in primary school is 0.26, and the maximum height is 0. 150.
The minimum width of stairs in buildings with dense people and heavy vertical traffic, universities and middle schools is 0.28, and the maximum height is 0. 165.
The minimum width of stairs in other buildings is 0.26, and the maximum height is 0. 175 (the design of civil air defense standard stairs is controlled according to this).
The minimum width of the stairs in the core tube of super high-rise building is 0.25, and the maximum height is 0. 18.
The minimum width of the maintenance and internal service stairs is 0.220 and the maximum height is 0.200.
Note: The step width of spiral staircase and sector step at 0.250 from the center of inner handrail should not be less than 0.220m.. ..
Description: The height-width ratio of stair treads is determined according to the gradient of stairs and the requirements of different types of human natural treads (steps), which meets the requirements of safety, convenience and comfort. Generally, the slope is controlled at about 30, and the requirements for stairs in residential suites where only a few people live are relaxed, but they should not exceed 45. The step is calculated according to the horizontal step company (2r+g), where r is the step height and g is the step width. Adults and children, men and women, young adults and the elderly are different, generally between 560 and 630, children around 560, and adults on average around 600. The height-width ratio of steps specified in this article can reflect the slope and step distance of stairs.
Buildings with crowded people and busy vertical traffic mainly refer to cinemas, theaters, concert halls, gymnasiums, shopping malls, hospitals, hotels, passenger stations, museums, exhibition halls, public libraries, amusement parks and so on.
Super high-rise buildings are often composed of different functional types. Because its daily vertical traffic mainly depends on passenger elevators, the evacuation stairs in the core tube of super high-rise buildings are rarely used at ordinary times, mainly for safe evacuation. Therefore, the requirements for the size of the steps are relaxed, and the minimum width of the steps can be 0.25m and the maximum height can be 0. 18m, so as to save the use space and organize the stairs reasonably.
6.8. 1 1 The height and width of each step in the bench should be consistent, and the height and width of the steps in the adjacent bench should be consistent. ()
Note: The tread height and width of each stair section should be consistent, and the adjacent stairs should be consistent, so as to ensure the comfort of the stairs and prevent wrestling. When the floor thickness of the first two steps and the last two steps of the same flight is different, attention should be paid to adjusting the height of the steps of the structure to avoid uneven height.
When the first floor staircase and the refuge floor are divided according to the requirements of the fire protection code, and the upper and lower stairs are not connected, they can be regarded as adjacent stairs, and the steps can be designed according to different heights and widths.
6.8. 12 When the above-ground and underground functions of the same building are different, the height and width of stair treads can be implemented according to Table 6.8. 10 of this standard.
Note: Considering the different functions on the ground and underground of the same building, the stairs can be designed according to the requirements of different building functions. Buildings with the same function on the ground and underground should have the same stair step height.
6.8. 13 Anti-skid measures should be taken when pedaling.
Description of provisions: Anti-skid measures should be taken for stair tread, such as anti-skid facing and anti-skid strips. The structure of anti-skid measures should pay attention to comfort and beauty, and the height of the structure can be flush, concave or slightly higher than the steps.
6.8. 14 When the stairs are clearly defined in the Standard for Design of Special Buildings, it shall be implemented according to the current National Standard for Design of Special Buildings.