边框SFRC剪力墙开裂弯矩影响因素和计算方法

Influence factors and calculation method of crack moment of the shear wall with SFRC in boundary elements

针对剪力墙边缘构件受力复杂、施工困难的特点，提出了在剪力墙边缘构件中采用钢纤维局部增强的方法来改进其抗裂性能，并将其命名为边框钢纤维混凝土（SFRC）剪力墙。结合试验结果和有限元数值模拟，研究了钢纤维体积率和轴压比对边框SFRC剪力墙抗裂承载力的影响。结果表明，边缘构件钢纤维体积率为1．5％-2％之间时对剪力墙开裂弯矩增强效果最好，最大提高幅度达45．1％。相对于整体钢纤维混凝土剪力墙，仅边缘构件采用钢纤维增强的剪力墙在未降低过多承载力的情况下，具有较好的经济优势。基于上述计算结果，提出了边框SFRC剪力墙开裂弯矩计算公式中主要参数的取值建议和开裂弯矩的简化计算方法，可供该类剪力墙设计验算时参考。

In view of construction difficulty and complex stress state of boundary elements, a method using steel fi- ber reinforced concrete（SFRC） in boundary elements is proposed to improve the crack resistance of shear wall. Combined with test results and finite element numerical simulation, the crack moment of this kind of shear wall with different steel fiber volume ratios and axial load ratio are studied. Results show that the crack resistance will experi- ence a remarkable increase up to 45.1% when the steel fiber reinforced concrete in boundary elements is between 1.5% and 2%. Compared with the overall SFRC shear wall, the shear wall with SFRC only in boundary elements does not reduce excess crack resistance, and has great economic advantage. Based on the above calculation results, main parameter values in the calculating formulas of cracking moment is determined, and a simplified calculation method is then proposed, which can serve as a reference for design and calculation of the kind of shear wall.