Comfort analysis on a long cantilevered steel spiral stairs
As a small space structure,steel spiral stairs are more and more popular.At present,there is no corresponding guidance standard at home and abroad in calculating the comfort of spiral stairs.Referring to the relevant data at home and abroad,the pedestrian load selection,the influence of pavement surface and the comfort evaluation standard of steel stairs were studied.Based on the actual project,the time history analysis method was used to analyze the comfort of stairs under different load conditions.The results show that for single-sided beam cantilever spiral stairs,the surface has little influence on the stiffness of the structure,and its stiffness influence can be ignored in the design.When ignoring the influence of human damping,the pedestrian load on the corresponding stairs will be calculated,and the acceleration calculation result will be too large,it is suggested to use the standard of three-dimensional weighted root mean square acceleration to evaluate the comfort.Under the crowd load,due to the different directions of horizontal loads caused by the spiral stairs,there is a counteracting effect.Therefore,when evaluating the comfort of spiral stairs,only the vertical acceleration can be considered on the premise that the horizontal stiffness meets the requirements.