If the ground is a multi-storey building, Article 5.3. 14 of Code for Fire Protection Design of Buildings (GB 500 16-2006) stipulates:

Unless otherwise specified in this code, the respective total widths of evacuation walkways, emergency exits, evacuation stairs and room evacuation doors in buildings shall be determined by calculation. The clear width of emergency exits and room evacuation doors should not be less than 0.9m, and the clear width of evacuation walkways and stairs should not be less than1.1m;

Article 5.3. 15 stipulates that there should be no threshold for evacuation doors in crowded public places and audience halls, and its clear width should not be less than1.4m. There should be no steps inside and outside the doors1.4m..

Article 5.3. 15 is described as follows:

Crowded public buildings mainly refer to buildings with public spaces where more than 50 people gather at the same time. Such as hotels, restaurants, shopping malls, markets, gymnasiums, auditoriums, exhibition halls of public exhibition halls, stock exchanges, public places of entertainment, outpatient and ward buildings of hospitals, sanatoriums, nurseries, kindergartens, teaching buildings, libraries and dormitories of schools, reading rooms of public libraries, passenger stations, docks and waiting rooms of civil airports.

Public places of entertainment mainly refer to the following indoor places open to the public: theaters, video halls, auditoriums and other performance screening places, dance halls, karaoke halls and other song and dance entertainment places, nightclubs, music cafes, restaurants with entertainment functions, amusement places, bowling alleys, roller skating rinks, saunas and other entertainment, fitness and leisure places.

In addition to the kitchen, the basement is an equipment room, which is not a public place, so the number of people cannot be calculated according to the business hall of the store. If the kitchen-bathroom ratio is 1: 1. 1, the above-ground business hall is 1000 square meters, and each third-class restaurant is 1 square meter. There are 65,438+0,000 seats (these two parameters are quoted from the first section of Chapter 3 of Code for Design of Catering Buildings (JGJ 64-89)). It is estimated that each kitchen employee will serve 30 customers, and the number of people in the basement will not exceed 50.

In this way, the two stairs are designed according to the minimum clear width of Article 5.3. 14 1. 1 m, which can meet the evacuation requirements.

If the above-ground building is a high-rise building

Article 6. 1. 10 of Code for Fire Protection Design of High-rise Civil Buildings GB 50045-95(2005 edition) stipulates:

The clear width of the doors of the evacuation stairwell and its antechamber should be calculated according to the number of people passing through 100 not less than 1.00m, but the minimum clear width should not be less than 0.90m·m m. The minimum clear width of the crib walkway of a house with rooms arranged unilaterally should not be less than 0.90 m.

6. 1. 12.3 The total width of evacuation exits in crowded halls and rooms shall be calculated according to the number of people passing by, and every1000 people shall not be less than1.00m..

From this point of view, according to the previous estimation results, if the two stairs are designed according to the minimum clear width of 0.9 meters, they can meet the evacuation requirements.