Which buildings must be designed for performance-based fire protection?

Most of the buildings that are not included in the current national fire protection technical standards have been designed for performance-based fire protection, mainly large-space buildings, such as the Bird's Nest, all super-high-rise buildings and water cubes.

1. Concept of performance-based fire protection design

Performance-based fire protection design is a new building fire protection design method based on fire safety engineering. It uses the principles and methods of fire safety engineering, and according to the structure, use and specific conditions of combustible materials inside the building, designers can freely choose various fire safety measures according to different space conditions, functional conditions and other related conditions of the building, and combine them organically. The overall fire safety design scheme of the building is formed, and then the fire danger and harmfulness of the building are quantitatively predicted and evaluated by using the developed engineering method, so as to obtain the optimal fire safety design scheme and provide the most reasonable fire protection for the building structure.

Compared with the "positioning method" design, the performance-based design scheme pays more attention to whether it can achieve the "purpose" of "ensuring personnel evacuation and fire fighting and rescue from the influence of fire smoke", rather than sticking to the minimum smoke exhaust required by the code. Through scientific demonstration, the performance-based fire protection design scheme can provide a safer design performance effect than the local fire protection code. Comparatively speaking, the performance-based design scheme has the characteristics of effective design cost, diverse design schemes and more optimized design effect.

Two key points of performance-based fire protection design, the first is to confirm the hazards, and the second is to define the design objectives. Specifically, it is aimed at the characteristics of the building, the characteristics of the people in the building, the operation mode inside the building, the characteristics of the outside of the building, and the characteristics of the fire fighting and extinguishing organization. So as to select a design method and an evaluation method for each hazard or each design area. This design method breaks through the limitation of traditional design on building structure type, corresponding height and area, and provides more flexible and effective design selectivity.

Performance-based fire protection design includes establishing fire safety objectives, establishing quantifiable performance requirements, analyzing building and internal conditions, setting performance design indicators, establishing fire scenes and designing fires, selecting engineering analysis and calculation methods and tools, conducting safety assessment on design schemes, formulating design schemes and writing design reports. In the design process, it is necessary to quantitatively analyze the possible fires in buildings and simulate the development and spread of fire and smoke in typical fire scenes. Therefore, the workload of calculation and the demand for all kinds of basic data are great, and computer fire simulation software and other analysis and calculation tools are often needed.

2. The process of performance-based fire protection design

Performance-based design uses fire science and fire safety engineering to establish design indicators and evaluate design schemes; And use fire risk analysis and fire risk assessment to establish the parameters needed in the field from the overall goal and functional goal to the fire scene. Performance-based fire safety design is an engineering process, which can define non-engineering parameters, such as people's behavior and reaction in fire.

3. The content of performance-based fire protection design of buildings

Performance-based fire protection design of buildings mainly includes two aspects: one is the performance design to ensure the safe evacuation of people in buildings, and the other is the performance design to ensure the fire resistance of building components.

The performance-based design of personnel safety evacuation is considered from the perspective of personnel safety in buildings. By comprehensively considering the influence of various fire factors on personnel escape, the performance-based design method is adopted to ensure the fire safety of personnel in the building, thus preventing casualties. The criterion of performance-based design is that it takes longer for the smoke layer to fall and the smoke concentration to reach an unbearable level than for safe evacuation.

The fire-resistant performance-based design of components is considered from the perspective of building stability. By analyzing the response of building components in fire, performance-based design method is adopted to ensure the fire stability of building structures, thus preventing the collapse of buildings. The performance-based design criterion is that the fire duration is less than the fire resistance time of the component.