柱截面变化对框架结构现浇板受力性能的影响研究

Research on Cast-in-situ Reinforced Concrete Slabs of Frame structures by Considering Influence of Varying Column Section

由于土地的紧缺,高层、超高层的建筑越来越受到开发商的亲睐。随着总层数的增加,下部楼层的柱截面越来越大,而梁截面变化不大,这使得对应的楼板更接近于异形板。这种情况下,楼板的计算和配筋往往还沿用单向板或双向板的设计方法和构造要求,忽略异形板受力尤其是应力分布上的特殊性,导致楼板转角处出现应力集中,甚至开裂。采用ANSYS软件进行大截面柱框架结构的数值模拟,从楼板主拉应力、弯矩、屈服线以及开裂程度等方面,研究了竖向荷载作用下柱截面变化对楼板的影响;通过对实际工程的有限元数值模拟,验证了ANSYS分析钢筋混凝土楼板的有效性,最后结合数值模拟为大截面柱框架结构楼板的设计和构造措施提出了一些建议。

Nowadays, high-rise buildings are constructed more extensively due to the lack of land. With the increase of stroreys, column cross-sections of lower storeys are relatively large and beam cross-sections remain unchanged,which makes the corresponding slabs become special-shaped plates. However, designers still use traditional design methods, i. e. , one-way slab or two-way slab and the corresponding detailing measures, ignoring special mechanical behaviors of special-shaped plates, especially their particularity of stress distribution that lead to cracks. Through theory analysis and ANSYS numerical simulations, mechanical behaviors of slabs of large-section column frame structures under vertical load action are studied in terms of principle tensile stress, bending moment, yield line and cracks by considering varying column sections. Finite element analysis is also performed on an actual engineering project, which verifies the effectiveness of the slab analysis by ANSYS. Combined with the finite element analysis, some useful suggestions are provided for the design and construction measures of slabs of frame structures with large-section columns.