钢板箍加固素混凝土柱轴压性能研究

Research on Axial Compression Performance of Plain Concrete Columns Strengthened with Steel Plate Hoops

为探究钢板箍对素混凝土柱轴压性能的影响,文中以钢板预紧力、宽度及布置间距为分析变量,采用有限元方法对9个试件进行轴压试验,并根据试验数值修正了钢板箍加固素混凝土轴压承载力估算公式。研究表明,钢板箍不论是否施加预紧力,均可提高素混凝土抗压能力,但无预紧力时钢板箍有明显的应力滞后;素混凝土柱的极限轴压承载力主要由柱身材料决定,钢板箍宽度、布置间距或预紧力在较小位移下仅影响柱体刚度,在较大位移下可提高柱体轴压承载力。运用统一理论的计算公式经修正后,可用于钢板箍加固正方形截面素混凝土柱的轴压承载力估算。

In order to investigate the effect of steel plate hoops on the axial compression performance of plain concrete columns,9 specimens were subjected to axial compression tests using finite element method with the analysis variables of preload,width,and spacing in this paper.Based on the experimental values,the estimation formula for the axial compression bearing capacity was revised.The steel plate hoop can improve the compressive strength of plain concrete regardless of whether pre tightening force is applied or not,but there is a significant stress lag in the steel plate hoop without pre tightening force.The ultimate axial compression bearing capacity of plain concrete columns is mainly determined by the material of the column body.The width of steel plate hoops,arrangement spacing,or preload only affect the stiffness of the column under small displacement,and can improve the axial compression bearing capacity of the column under large displacement.After correction,the calculation formula based on the unified theory can be used to estimate the axial compressive bearing capacity of square section plain concrete columns strengthened with steel plate hoops.