Stress strain state and applicability conditions of the main types of erection joints for columns in steel frames of multi storey civil buildings

Introduction. With the development of steel frame construction for multi-story civil buildings, the rational design of column assembly joints, based on knowledge of the actual nature of the column stress-strain state, is becoming particularly relevant. These joints are among the key components determining the load-bearing capacity, stability, and spatial rigidity of the frame. Regulatory documents provide limited recommendations for selecting a joint type depending on the column stress-strain state, which requires additional research and calculation and analytical justification. Materials and Methods. This study presents a parametric study of the stress-strain state of the main types of column assembly joints: joints with a milled end, welded and bolted joints on platens, and flanged connections. The joint performance was studied for the most common types of frame systems used in construction practice. The relative eccentricity of the longitudinal force in the column was chosen as the primary criterion determining the applicability of the joint type. The calculated forces were obtained based on the linear calculation of spatial models of frames in the LIRA-SAPR software package. The analysis of the joint performance was performed using the component finite element method in the IDEA Statica software package. The efficiency of the connections was assessed using the coefficient of utilization of the bearing capacity of joint elements (welds, bolts, plates), as well as steel consumption and erection rate. Results. The dependence of the coefficient of utilization of assembly joint parts and connections on the relative eccentricity and frame type was established. The areas of rational application of various joint types were determined: for m ≤ 0.1 – a joint with a milled end; for 0.1 < m ≤ 2 – a welded joint on cover plates and a flanged joint; for 2 < m ≤ 5 – a welded and bolted joint on cover plates; for m > 5 – a bolted joint on cover plates. The inappropriateness of using a gap between column elements in overlay connections and the inefficiency of using physical methods to control column assembly joints at m ≤ 0.1 were revealed. Conclusions. An algorithm for selecting an appropriate type of column assembly joint was developed, taking into account design, structural, installation, and economic criteria. Implementation of these recommendations allows for optimization of design solutions and a reduction in metal consumption and installation labor intensity.