带约束拉杆方形薄壁钢管/竹胶合板组合空芯柱轴心抗压性能

为解决方形薄壁钢管/竹胶合板组合空芯柱（SBCC）在压缩载荷下易开胶失效的问题，提出了一种新型的带横向约束拉杆的方形薄壁钢管/竹胶合板组合空芯柱（SBCCB）。首先，对9根SBCCB进行了轴心抗压试验，考察了SBCCB受压破坏形态，分析了SBCCB的截面尺寸、长细比和截面组合方式对其开胶载荷和极限承载载荷的影响，并将SBCCB的极限压应力与已有的SBCC数据进行了比较；然后，通过非线性回归分析，建立了SBCCB轴心抗压承载力计算公式。结果表明:SBCCB的轴心抗压失效破坏主要为柱端及柱身横向约束拉杆之间的竹胶合板开胶失效和竹胶合板材料破坏失效，其极限承载力不仅与截面尺寸和长细比相关，而且受截面组合方式影响。设置横向约束拉杆可有效减缓开胶失效，改变极限破坏模式，显著提高极限承载力；与SBCC的极限压应力相比，SBCCB的极限压应力平均提高26%。 

Axial compression behavior of square thin-walled steel tube/bamboo plywood composite hollow column with binding bars

A new type of square thin-walled steel tube/bamboo plywood composite hollow column with horizontal binding bars (SBCCB)was proposed to solve the issue that the square thin-walled steel tube/bamboo plywood com-posite hollow column (SBCC)was liable to glue failure under compressive load.Nine SBCCB were used to perform the axial compression tests firstly.The failure modes of SBCCB loaded were investigated,the influences of the cross-sectional size,slenderness ratio and sectional combination mode of SBCCB on the glue failure load and ultimate bearing load of it were analyzed,and the ultimate compressive stress of SBCCB was compared with existing data of SBCC.Then,the calculating formula for the axial compression bearing-capacity of SBCCB was derived through the nonlinear regression analysis.The results indicate that the axial compressive failure damage of SBCCB is primarily the glue failure of bamboo plywood between horizontal binding bars of the end of column and the middle of column the glue failure as well as material broken damage of bamboo plywood.The ultimate bearing capacity is not only re-lated to the cross-sectional size and slenderness ratio,but also affected by the sectional combination mode.By set-ting horizontal binding bars,the glue failure binding can be suppressed effectively,the ultimate failure mode chan-ges,and the ultimate carrying capacity improves significantly.Compared with the ultimate compressive stress of SBCC,the ultimate compressive stress of SBCCB increases by 26% averagely.