The Study Of Seismic Behavior On Steel High-strength Reinforced Concrete Columns

With the development of modern construction, the height and the span of building are on the increase, the traditional structures of reinforced concrete can not meet requirements of the modern construction.If reinforced concrete columns are still applied in the high-rise building, it will result in increased size of columns section because of big axial compression and limits of axial compression ratio. This not only affects service function, but also may become short columns whose seismic behavior is poor. It is made known by a lot of experiments that steel reinforced concrete columns can effectively reduce the axial compression ratio of column's concrete part and improve seismic behavior of the columns. As a result of steel staring a part of axial load. So, steel reinforced concrete columns, specially steel high-strength reinforced concrete columns are used in modern construction widely. Axial compression coefficient is a important target that affects seismic behavior of steel high-strength reinforced concrete columns. Through repeatedly horizontal load tests, it is shown that ductility and seismic behavior of columns become worse when axial compression coefficient exceeds 0.4 to 0.5. For this reasion, the axial compression coefficient must be limited strictly in practical engineering in order to ensure seismic ductility of the columns reaching regulation requirement, In this paper, seismic behavior of steel high-strength reinforced concrete columns with "十" shape of steel are studied through the test of 6 columns, and Limited values of axial compression coefficient of the columns are obtained , which satisfy certain requirement of ductility.At first, based on certain basic assumption, Limited values of axial compression coefficient of steel high-strength reinforced concrete columns with "十" shape of steel are put forward through calculating. Then failure pattern and hysteresis characteristic of the columns are analyzed. The factors such as axial compression coefficient and stirrup ratio, which affect ductility of the columns, are researched. Present national regulations don't consider influence of steel shape when putting forward the limited values of axialcompression coefficient of steel high-strength reinforced concrete columns. So in thispaper, according to the test results, limited values of axial compression coefficient of steelhigh-strength reinforced concrete columns with "十" shape of steel and correspondentstirrup ratio are put forward, which satisfy certain requirement of ductility.And it shows by analyzing that the calculated results are corresponding with that of testwell.Through the test, seismic behavior on steel high-strength reinforced concrete columns with two different shapes of steel are contrasted. The result showed that seismic behavior on steel high-strength reinforced concrete columns with "十" in flanges shape of steel is better than that on steel high-strength reinforced concrete columns with "十" in no flanges shape of steel.