“…In this case, instead of 8 standard sections, it turns out to be possible to use only three sections. In this case, after rounding off the scale of sections, they take the form: 10, 35, 120 mm 2 ; 16, 50, 150 mm 2 ; 25, 70, 150 mm 2 [40][41][42][43][44][45][46][47].…”