Load Combination Requirements for Fire-resistant Structural Design

摘要

Fire protection of building structural systems traditionally has relied on component qualification testing, with acceptance criteria based on component survival during a "standard" fire for a prescribed rating period. These test procedures do not address the impact of the fire on a structural system. With advances in fire science and the advent of advanced structural analysis, the routine use of the computer as a design tool and limit states design, it is becoming possible to consider realistic fire scenarios and effects explicitly as part of the structural design process, In this modern engineering design approach, load requirements for considering structural actions due to fire in combination with other loads are essential, but have yet to be implemented in standards and codes in the United States. This paper provides a probabilistic basis for appropriate combinations of loads to facilitate fire-resistant structural design and recommends specific load combinations for this purpose. The probabilistic basis is essential for measuring compliance with performance objectives, for comparing alternatives, and for making the role of uncertainty in the decision process transparent.