The Fire-Resistant Design and Safety Assessment of a Composite Steel Framed Building(II)——Analysis of Structure and Fire-Resistant Design

The facts demonstrated in the experiments and the real fire hazards showed that the fire-resistant capacity of members in a global structure are different from the simply-supported beams and columns in fire conditions,which may be induced by the interaction between the members and the change of the distribution of the load on the members.While the above effects are not considered in the current fire safety standards,in the paper the performance based design method is adopted in the fire-resistant design of a composite steel framed building to consider the above effect in a global structure.In the global structural analysis,the catenary action and the interaction between the columns and beams play an important role on the fire-resistant capacity of the members,which cannot be ignored in the fire safety design.Based on the force in the members obtained by the global structural analyses,the fire-resistant capacity of the members is checked by the calculating method,which is more reasonable than the conventional design method.According to the latest achievement of the research on the membrane action of the floor slab subjected to fire,the membrane action is considered in the fire-resistant design of floor slab,which leaves some second beams unprotected and the cost of fire protection is reduced.