How thick does it take to make a doorpost with a steel column?

It takes 750 cm to make a door post with a steel column. Column size of the house: the maximum number of columns at the bottom is 750 times 750, and the maximum number of columns at the top is not less than 400 times 450. C60 concrete is adopted, and the shear wall thickness is 300 and 200. Columns are long-strip members used to support beam trusses in buildings. Vertical members in engineering structures mainly bear pressure and sometimes moment, and are used to support beams, trusses and floors.