椭圆形旋转楼梯内力分析及计算

Analysis and calculation of internal forces for elliptical spiral stairs

曲线形旋转楼梯在现代建筑中已较普遍使用。提出了一个可靠、简单、便于使用的内力工程计算方法。采取计算与构造相结合的方法,进行必要的计算简化和假定,在椭圆形旋转楼梯的内力计算时,把固定坐标变换成动点坐标,推导相应的计算公式。对某商贸中心的大型椭圆形旋转楼梯进行了内力计算。结果表明,该计算方法相对较简单,内力符合实际情况,用动点坐标系可易于获得楼梯各截面的轴力、剪力、弯矩和扭矩,便于设计。按此设计施工后各项指标均符合要求。该方法还可用于按其它曲线形状旋转的楼梯的内力计算。

Curved spiral stairs have been widely used in modern buildings. This paper developed a practical calculation method for engineers to predict their internal forces. From combining internal force calculation with design detailing, some calculation simplifications and hypotheses are first presented, then a calculation method and corresponding formulas of internal forces for elliptical spiral stairs are derived. A largescale elliptical spiral stairs of a world trade center building was designed according to the calculation results using this method. This calculation method is not very complex and the predictions are in agreement with actual stair internal forces. It is convenient to obtain the internal forces of any stair section for structural design using a moving coordinate system following a calculating stair section. The internal forces for other curved spiral stairs can also be calculated based on the mentioned method above.