コンクリート充填楕円鋼管柱の構造性能に関する研究

摘要

This study deals with the structural behavior of concrete-filled oval tubular (CFT) steel columns. The design formulae are proposed approximately on the yield bending moment and full plastic moment of the oval CFT cross section. They are available in the arbitrary loading direction by introducing simple power series of trigonometric function instead of the difficult elliptic integral of the 2nd kind. Experimentally, specimens were tested under reverse-symmetry cyclic loading to investigate the effects of the loading direction of the oval, axial force ratio, and deformation capacity of the CFT columns. The test results verify that these effects depend on the curvatures around the compressive edge of the oval tube sections. Based on the experimentally obtained equivalent diameter - to -thickness ratio (D/t) of elliptic tube, simple evaluation formulae are proposed on the confinement effect and deformation capacity of the oval CFT columns.%コンクリート充填鋼管柱(以下CFT柱)の断面形状には主に正方形並びに円形が用いられており、それらの断面については計算規準1),3)、設計施工指針2),4)、技術基準5)、及び技術書6)等が整備されている. 正方形・円形以外の異形断面に関しては、長方形断面のCFT柱の力学性状に関する実験的研究に山口ら7)～11)らが行ったものがある.