为增加型钢混凝土(SRC)柱在高轴压比下的抗震性能,提出一种对角线布置的十字形SRC柱。由于其承载力计算不能直接采用JGJ 138—2001《型钢混凝土组合结构技术规程》或YB 9082—2006《钢骨混凝土结构设计规程》中的相关公式,采用强度叠加法和极限平衡法对其正截面受压承载力进行研究。先按强度叠加法分别计算约束混凝土、型钢翼缘和型钢腹板的承载力,再按照叠加理论得到最大轴力和极限弯矩;极限平衡法从材料力学的思路出发并进行推导,通过统计分析大量双向偏压十字形SRC柱的数值模拟结果,进而得到柱正截面受压承载力简化计算式。采用所提算式对3根试验柱和16根有限元模拟对角线布置十字形型钢混凝土柱进行计算,理论结果与柱实际承载力符合良好,验证了所提算式的正确性和适用性。
For the purpose of improving seismic performance of steel reinforced concrete ( SRC) columns with high axial compression ratio, SRC columns with cross-shaped steel along diagonal line were put forward, whose bearing capacity calculation could not adopt the related formulas of current codes directly.The strength superposition method and limit equilibrium method were employed to calculate normal section bearing capacity of proposed SRC columns on this background.The bearing capacity of confined concrete, steel flange and steel web were calculated respectively first, and then the maximum axial force and ultimate moment were obtained according to superposition principle of the strength superposition method.From the thought of material mechanics, the simplified calculation formulas of normal section bearing capacity were deduced through regressing numerical simulation results of a large number of SRC columns with cross-shaped steel subjected to biaxial eccentric compression of limit equilibrium method.Three experimental specimens and sixteen finite element simulated columns with the same sections were calculated using the above formulas and the theoretical results agreed well with practical bearing capacity of the columns, which verified the correctness and applicability of the proposed formulas.