STUDY ON DESIGN METHOD OF AXIAL FORCE-MOMENT CAPACITY AND SECTIONAL DEFORMATION CAPACITY OF STEEL TUBE CINFINED HIGH-STRENGTH CONCRETE SHEAR WALLS

Cyclic loading tests of steel tube confined high-strength concrete shear walls with shear span ratios of 2.1 were conducted, and the failure pattern, mechanism and deformability under axial force-moment load were studied. The test shows that by providing confinement to the wall panel with steel tube, the ductility of specimens are improved. Based on experimental results, axial force-moment capacity and deformation capacity of steel tube confined high-strength concrete shear walls were analyzed. By considering the confinement of steel tube, axial force-moment capacity formula was established. Based on the equilibrium and deformation condition, the displacement ductility ratio of steel tube confined high-strength concrete shear walls was calculated. The mutual relationships among steel stirrup ratio, axial compression ratio, aspect ratio and displacement ductility ratio were obtained. The result shows that enhancing steel stirrup ratio and restraining axial compression ratio can improve ductility performance. Furthermore, the steel stirrup ratios with various deformation capacity and axial compression ratios are recommended.