Base Plate Design For Steel Column

In addition to selecting the column and the grade of concrete the user must select the size thickness and steel grade of the baseplate.

Base plate design for steel column.

Design guide 7 covers the pinned column base plate connection. Typical column bases as shown below consist of a single plate fillet welded to the end of the column and attached to the foundation with four holding down bolts. 2 september 2002 design of. High strength grout is poured into the space below the plate.

Design of base plate with shear four principal ways of transferring shear from column base plate into concrete 1. Baseplates for circular and square hollow sections must be square. The design compressive strength of the concrete is determined from. The aisc manual of steel construction reference 3 provides a two step procedure for the design of axially loaded base plates.

Embedding column in foundation 3. N d 2 3 in b bf 2 3 in 2. Determine plate cantilever dimension m or n in direc tion of applied moment. 0 35 f c a 0 70 f c.

Concrete for concrete grade c30 37 characteristic cylinder strength f ck 30 mpa 30 n mm 2. Friction between base plate and the grout or concrete surface n u c c v p f a m 0 2 the friction coefficient m is 0 55 for steel on grout and 0 7 for steel on concrete 2. The bolts are cast into the concrete base in location tubes or cones and are fitted with anchor plates to prevent pull out. I divide the factored column load by the design bearing strength of concrete and find the area of the base plate.

The recommended design model draws extensively on the american institute of steel construction steel design guide 1 base plate and anchor rod design second edition and on the australian steel institute publication steel construction vol. F cd α cc f ck γ c f cd 0 85 x 30 1 5 17 n mm 2. Design guide 7 provides a recommended design model for pinned base plates for both open and closed column sections subject to compression and tension actions and completes the revision of structural steel connections 4th edition 1994 often referred to as the green book. Width of base plate depth of the column section 2 thickness of gusset plate 80 mm to 100 mm.

B 4 1 design procedure for a small moment base 1. Such column bases are usually assumed to be subject to axial compression and shear only. The graphics show the column the baseplate grey and the effective area yellow overlay. First the area of the plate is calculated based on the allowable beating stress defined by the following equations.

M n 0 95d 2 n b 0 80bf 2 3. Select a convenient width of the base plate. Choose trial base plate sizes b and n based on geom etry of column and four anchor requirements.