内置高强角钢的方钢管混凝土柱偏压性能试验

Experiment on Eccentric Compressive Behaviors of Square CFST Columns with Built-in High-strength Steel Angles

为了揭示内置高强角钢的方钢管混凝土柱偏压性能,开展了8根该类柱及2根传统方钢管混凝土柱的偏心受压试验,考察了取钢率(角钢质量与总用钢质量之比)、角钢到钢管内壁净距、偏心距等主要参数对柱偏压性能的影响,探讨了内置高强角钢的方钢管混凝土柱偏压承载力计算方法。结果表明:在总用钢量基本保持不变的情况下,合理确定取钢率和角钢到钢管内壁净距,能够使内置高强角钢的方钢管混凝土柱偏压性能和传统方钢管混凝土柱基本相当;相比于取钢率,角钢到钢管内壁净距对内置高强角钢的方钢管混凝土柱偏压承载力影响更为明显;总用钢量保持不变时,相比于传统无内置角钢试件,内置高强角钢试件的等效刚度及延性总体上改变有限;对于内置高强角钢的方钢管混凝土柱,在达到偏压峰值荷载时,柱受压区或(和)受拉区的高强角钢已充分发挥其强度;针对内置高强角钢的方钢管混凝土柱改进提出的偏压承载力实用计算方法总体上具有良好的精度。

In order to clarify the eccentric compression behaviors of square concrete-filled steel tubular(CFST)columns with built-in high-strength steel angles,eight such columns and two traditional steel tubular columns filled with concrete were tested under eccentric compression.The effects of the replacement ratio of steel(the mass ratio of the steel angles to the total steel usage),the clear distance between the steel angle and the steel tube,and the eccentric distance on the eccentric compression behaviors of the columns were investigated,and the calculation method of the eccentric load bearing capacity of the square CFST column with built-in high-strength steel angles was discussed.The results show that when the total steel consumption remains unchanged,through reasonable selection of both the replacement ratio of steel and the clear distance between the steel angle and the steel tube,the eccentric compressive behaviors of the square CFST column with built-in high-strength steel angle is similar to that of the traditional CFST column under eccentric load.Compared with the replacement ratio of steel,the clear distance between the steel angle and the steel tube has greater influence on the eccentric load bearing capacity of the square CFST column with built-in high-strength steel angles.When the total steel usage keeps unchanged,the equivalent stiffness and ductility of the square CFST column with built-in high-strength steel angles are close to those of the traditional square CFST column.When the square CFST columns with built-in high-strength steel angles reach their eccentric peak loads,the high-strength steel angles in the compression or(and)the tension zones have fully exerted their strength.The improved calculation method of the eccentric load bearing capacity of the square CFST column with built-in high-strength steel angles can predict the peak load well on the whole.