Column Details Part 3 0500239

Where box columns are used, it is better to keep the spacing back to back of channel the same throughout all sections. If this is less in the upper sections, it brings the load of this section on to the horizontal splice plate between the sections. The distance between the cap and shelf angles is generally 1/8 in. more than the depth of the beam, to allow for clearance. The rivets between the cap and shelf angles are flattened here, as with one beam in position there would not be space to lower the other beam between the rivet heads.

Fig. 215 gives the bill of material for these box columns. Fig. 216 shows the framing of the beams coming on columns No. 1 and No. 2. detailed in Fig. 217. This column has a heavy steel base riveted to it. The load on the section is 265,000 pounds and it will be seen therefore that the rivets in the shear plates are amply sufficient for the portion of the load coming upon them. The plate W riveted to the web increases the bearing area of the foot of the column and adds somewhat to the efficiency of the base.

In this connection and in such cases where shear angles are used over a shelf angle involving the use of a filler, below the shelf angle and back of the shear angles, as shown by the details of this column, the student should note the difference between a tight and a loose filler.

Fillers G and R are loose fillers. They have no rivets holding them individually to the main members. The stress in the rivets through such a filler does not go into the filler, as there are no extra rivets to take it out again from the filler to the main members. Such rivets, therefore, are subject to bending if calculated for their full value. They should not be considered for more than one-half the value of rivets directly connecting the main members. Filler W is a tight filler as regards the two rivets through the angles X on the axis of the column. A tight filler has provision by additional rivets for taking the same amount of stress from itself to the main member as it receives.

The open holes shown in the base plate are for anchoring to the footing - such heavy columns are not usually anchored except in special cases; it is well, however, to provide for this if there is any possibility of its being required.

Bill of Material for 2 Columns

ITEM

NO OF

PIECES

KIND

SIZE

LENGTH

WORK

FEET

INCHES

2

WEB PLS.

12"X1/2"

24

8 3/4

FACED BOTH ENDS

8

FLG. LS

6"x3 1/2"x1/2

24

8 3/4

,, ,, ,,

A

4

SPL/CEPLS

12 1/2"x1/2"

1

6 1/2"

BEVELLED

B

4

ANGLES

6"x4"x1/2"

0

10 3/4"

SHIP BOLTED

c

4

F/LLERS

5"x1/2"

0

5 3/4

,, ,,

D

4

ANGLES

6"x6"3/8"

0

8 7/8

BEVELLED

E

4

,,

6"x6"1/2

0

8 7/8

BEVELLED

F

4

ST/FF.LS

4"x3"x3/8"

0

8 1/2

,, FITTED

G

4

FILLERS

2 3/8"x1/2"

0

2 3/4

H

4

ANGLES

6"x6"x3/8"

0

5

SH/P BOLTED

J

4

,,

6"x6"x1/2"

0

5

K

8

STIFF LS

3"x2 1/2"x5/16"

0

8 1/2

F/TTED BEVELLED

L

4

F/LLERS

2 3/4"X1/2"

0

5

M

4

ANGLES

6"x6"3/8"

0

10 3/4

SHIP BOLTED

M

4

F/LLERS

3"x1/2"

0

5

,, .

N

4

ANGLES

6"x6"1/2"

0

10 3/4

0

4

,,

6"x6"x3/8"

0

8

SHIP BOLTED

P

4

,,

6"x6x1/2"

0

8

Q

8

STIFF. Ls

4"x3"x5/16"

0

8 1/2

FITTED BEVELLED

R

4

F/LLERS

2 3/4"x1/2"

0

8

S

4

PLATES

18"x1/2"

2

0

FACED BEVELLED

T

4

ANGLES

6"x4"x1/2"

2

0

BEVELLED

U

8

STIFF Ls

4"x3"3/8"

1

5 1/2

FITTED BEVELLED

V

4

F/LLERS

8"x1/2"

0

11 3/4

w

4

PLATES

10 3/4"x1/2"

1

0

FACED

X

4

ANGLES

6"x4"x1/2"

0

10 3/4"

Y

4

F/LLERS

5"x1/2"

0

11 1/2

z

2

BASE PL S.

24"x3/4"

2

0

COUNTERSUNK

6

BOLTS

3/4"

0

3 1/2

12

,,

3/4"

0

3

20

,,

3/4"

0

2

Fig. 218.

In the connection for floor beams it will be noted that a 10-in. beam comes in on one side of the web and a 12-in. beam on the other side. Such cases often result in special cap angle details in order to provide for riveting without interference on either side. In this case it is impossible to get the upper holes in cap H more than 3/4 in. from the upper edge of cap M unless these holes are brought nearer the upper edge of 1 1/4 than 1 1/4 in., which it is undesirable to do. It is necessary, therefore, to add an extra filler B B to fill out flush with the angle N so as to be able to rivet. The student should follow the detail through and see just why this condition results from the measurements given.

The four rivets in angles L are countersunk on the far side so as to avoid a filler and riveting through angle N.

The 10-in. beam connecting on the flange of the column at one side of the axis, requires a connection similar to that shown. If the load coming off the axis was very heavy, a deeper shear plate would be used back of the shelf angle, and it would be better to run this shear plate across both angles of the flange, both to provide for the bending on the rivets and also to distribute the load more uniformly with respect to the axis of the column.

There are no standard details for eccentric and special framings. The draftsman must use his judgment and endeavor to get as simple and effective connections as possible.

The section which comes on top of this one has 5-in. angles, in order to use standard spacing in these angles, therefore, the spacing in splice plates has to be on a special gauge and this place is beveled to give a neater appearance when the two sections are riveted together. Fig. 218 gives the bill of material.

Fig. 219 gives the detail of an angle over an opening resting in a wall at one end and framing to a beam at the other. The holes in the horizontal leg are for securing the frame of the window. As this angle has framing on one end only it is not reversible and therefore for the wall on opposite side of the building the angle must be made "opposite hand" or reversed.

Column Details Part 3 0500240

Fig. 222.

Column Details Part 3 0500241

Fig. 219.

Column Details Part 3 0500242

Fig. 221.

Fig. 220.

Column Details Part 3 0500243

Fig. 220 gives the detail of a spandrel girder and shows in outline the relation of the stone facing to the girder. This wall section is a pier and the width of it is indicated by the length of the 8-in. channel at the right-hand end. At the opposite end the wall is only a covering; for the column and is carried on the column. This channel supports the block surrounding it, which in turn supports the mass of stone above; the course below is hung by anchors, to the 8-in. channel. The channel is supported by brackets from the beams which are detailed separately for clearness, although they are shipped riveted to the beam. The connection A runs back to the column. There are two floor beams framed to the girder, but as the space between center of beams is 11 in. there is sufficient room to drive rivets passing through only one beam, and this is preferable, therefore, to using through bolts.

Note the specification "Ship Unassembled". This means that the two beams are not bolted together for shipment.

Fig. 221 gives the detail of a cast iron base for a plate and angle column having a 12-in. web. The outlines of the members of the column shaft should be carried down by similar outlines in the cast iron base. In this case the box of the base is H-shaped and the centers correspond to the centers of the shaft members. The thickness of this box under the column must be sufficient to carry the whole load of the column without exceeding the safe compressive strength of cast iron. The size of the base depends upon the area required to distribute the load on the footing. The purpose of the ribs and base is to resist the tendency to break, due to this uniformly distributed load on the footing. Failure would generally occur through the bending action of the portion of the base projecting beyond the box. The moment on this may be figured as for a beam fixed at one end and free at the other and loaded uniformly with the load per unit of bearing surface.