Weight characteristics and areas of rational use of central compressed steel columns

Abstract

Six types of central compressed steel columns are considered: rolled and welded I-beams, square pipes, two channel bars connected via planks, four metal corners connected via planks or lattices. The experimental design of columns of all types was carried out with various combinations of heights up to 20 meters and the load on the column up to 9 MN.

It is shown that the sections of welded I-beams, as well as four-branch columns connected via planks or lattices can be selected for all combinations of height and load within the specified limits. The areas of possible use of columns from rolled I-beams, square pipes and two channel bars connected via planks are limited by the serviceability limit and ultimate limit state of the rolled profiles from the respective assortments.

According to the design results, the dependencies of the optimum cross-sectional dimension of the welded I-beams and four metal corners connected via planks or lattices on the load and the height of the column are established and described by analytical expressions. A unified type of analytical dependence of the linear mass of central compressed columns on their height and current load is proposed. The coefficients of these dependences for the columns of the six types are obtained by approximating the results of experimental design using the least squares method.

According to the results of a comparative analysis, the areas of rational use of central compressed columns of six types are set according to the criteria of metal consumption and cost. In most cases, four metal corners connected via planks or lattices is characterized by the least metal consumption, but at low heights and high loads - welded I-columns. According to the cost criterion, in most cases it is better to have welded I-columns, and four metal corners connected via planks or lattices have the lowest cost at high heights and small longitudinal forces.