Numerical Assessment of Connections with Reduced Beam Sections under Fire-Following an Earthquake Using Continuously Updated Boundary Condition

摘要

The occurrence of fires following an earthquake in steel structures is an important scenario that can threaten the integrity of structural systems. Structural loss due to such combined events has been observed and reported. Despite such evidence, minimal studies have been conducted on the combined effects of the hazards on steel structures or any type of structures for that matter. The aim of this paper is to provide insight into the local behavior of reduced beam section connections during fire following earthquakes when representative time-dependent boundary conditions are utilized to simulate the restraint provided by the surrounding frame during the fire. This is achieved through investigating the response of two beam-column subassemblies designed for the Los Angeles region using 3D nonlinear finite element analyses. The models are developed and analyzed under several representative loading scenarios with continuously updated boundary conditions that characterize the nonlinear stiffness of the remainder of the frame. The results are presented and their implications discussed to protect against the hazard of fire following earthquakes in steel moment frames with reduced beam sections.