关键词：钢铁;固有频率;柔性接头;土结构相互作用
摘 要：The paper presents changes of natural frequencies of industrial steel hall due to simplifications or changes of numerical model.Firstly,the natural frequencies were calculated for basic Variant A of the numerical model of the steel hall which consisted of the main frames,footings,roofpurlins and girts.In this Variant columns were fixed at bases,both purlins and girts were rigidlyconnected to main frames and designed as continuous beams.Then,in Variant B of the model columns were pinned at bases.Next,in Variant C different types of connections (semi-flexible joints)of roof purlins and girts with the main frame were implemented.Finally,in Variant D,soil-structure interaction was taken into consideration.The calculations of the dynamic characteristics of four abovementioned Variants of the numerical model of the hall showed that simplifications or changes of some details of the structure could result in significant errors in values of natural frequencies.