单层带支撑异形柱框架的高温性能研究

针对单层异形柱框架,通过高温数值分析,考察了支撑设置和受火位置对结构高温变形及内力的影响。研究结果表明:对于单层多跨异形柱框架,当只有一端有支撑跨时,会在一定程度上增大另一端的边节点水平位移和边柱侧向变形,对结构整体抗火不利;当左、右两端均有支撑跨时,非支撑跨在火灾作用下的梁轴力比很大,升温后期可能因梁跨中竖向位移急剧增大而发生破坏。基于上述研究结果,给出了4类单层带支撑异形柱框架火灾行为的初步判定方法。

Fire Behaviors of Single Story Frames with Specially Shaped Columns and Bracings

The influences of brace and fire locations on deformations and internal forces of single-story RC frames with specially shaped columns at high temperature are investigated.Simulation results show that:In the case that braces are located at one side of a single-story multi-span frame,the lateral deformation of the opposite side column increases,this is disadvantageous for structural fire resistance;In the case that braces are located at both left and right end-spans of a single-story multi-span frame,the axial force ratios of beams in non-bracing spans subjected to fire are large,which may lead to collapse of these beams at the late heating time.At the end,an assessment method is proposed for fire behaviors of four kinds of singlestory frames with braces and specially shaped columns.