This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
As the beam is a 15-in. beam, while on one side is a 12-in. terra cotta arch, it is necessary to provide an angle on this side. The bottoms of the 9-in. beams are 3 in. above the bottom of this 15-in. girder, and if the connections were central with the 9-in. beams, the first hole would be 6 1/4 in. from the bottom of the 15-in. beam. In order to get clearance between this hole and the upper edge of shelf angle sufficient to drive the rivet, and to avoid cutting the angle at each connection, the shelf angle is dropped, making the upper side of the outstanding leg flush with the bottom of the 12-in. beams, and the connection on the 9-in. beams raised 1/2 in.
Fig. 205 gives the detail of beam No. 12. In this case, the length of beam cannot be obtained directly from the framing plan, as the beam No. 1 is not perpendicular to beam No. 12. The difference in measurement of the ends of No. 1 from the wall line is 1 ft. 10 in., and the length parallel to this wall and square with beam No. 12 is 12 ft. 8 in. from the center of the column. As No. 12 is 4 ft. 2 1/2 in. from the center of the column, the bevel from the column to No. 12 is 4 21 4.21/12.67 X 22 = 7.31 inches, or 7 5/16 in., to the nearest sixteenth.
The length of No. 12 from the face of wall to center of No. 1 on this line, therefore, is 14 ft. 10 11/16 in. The bearing on wall being 8 in., and the clearance at the other end 1/4 in., the total length of beam is 15 ft. 6 7/16 in.
The girder No. 1 coming under the sidewalk is 4 in. lower than beam No. 12. This is not enough to get a shelf angle on the girder, or to get angles over the top of the girder, as in the case of beam No. 11. It is necessary, therefore, to drop the connection on No. 12 and notch the beam over the top flange of No. 1. This notching is not figured on as reducing the required number of rivets in the connection, but does give an added element of strength and of stiffness. In order to get the connection in, it is necessary to go within 1 in. of the bottom flange of No. 12 and the top flange of No. 1; thus encroaching somewhat on the fillet in each case. As the required number of rivets can not be obtained in two lines, as is generally the case, it is necessary to use special spacing as shown. The connection specifies bent plates rather than angles; where the bevel is over 1 in. to the foot, it is customary to use plates.
Fig. 20G gives the detail of channel No. 17. This channel has a single angle framing. This is a case where the channel comes into a wall so that a connection angle on the back side cannot be reached. In order to get the necessary number of rivets in the outstanding leg, therefore, a 6 X 6-in. angle must be used. The holes at the left-hand end in the web are for the connection of a channel similar to what is shown in the end view.
These holes are located from a line which in turn is located from the end of the channel; this axis is the back of the channel framing in.
Note the over-all lengths of the tie rods is 3 in. longer than the length, center to center of beams. This allows 1 1/2 in. for the two nuts, about 3/8 in. for half the thickness of the two webs and about 9/16 in. projection of rod beyond the nut. The length of field bolts is always given from the underside of the head to the end of the bolts. The grip is the thickness of the metal between the underside of the head and the nut; that is, the thickness of the connection angles and the web. A projection of 1/4 in. or 1/2 in. beyond nut should be allowed for. Fig. 208 shows the setting plan of another floor, a part of which the student will be required to detail as problems.
Fig. 209 shows the detail of the beam girders, Nos. 2 and 3. As the beams are spaced close together, connections can be used only on the outside of the webs. The same number of rivets in the out-
Schedule: of Tie Pods
. ,, ,,
Schedule of Field Bolts.
for FIRST FLOOR
Schedule of BeARing Plates for FIRST FLOOR
No Of PIECES
8" X 1/2"
8" X 3/4"
standing legs must, of course, be used, as would be required for a double-angle connection, and more rivets must be used through the web, as these are in single shear instead of bearing or double shear. In the case of the beams shown, seven rivets are all that are necessarv, although the standard connection requires eight.
In such a connection as girder No. 2 to girder No. 1, it is necessary to use bolts, as there is no way of riveting. In the case of the connections of beams to girders Nos. 2 and 3, rivets might be used by separating the two beams forming each girder and sliding the framing of each outside bay over on the wall far enough to get in between the beams of girders to hold the rivets. After all the beams had been riveted up, the whole frame could then be moved back into position, and the girders bolted up. Such an operation would be expensive, as it would require considerable extra moving of the beams. In general, bolts through webs of both beams would be used. If the connection was very heavy or the greatest possible number of bolts barely sufficient for the load, turned bolts should be used. In this case, the holes should be punched 1/16 in. smaller than the diameter of the rivet, and then reamed to a diameter 1/16 in. larger than the rivet so as to remove all ragged edges; the bolts would be turned down to a true diameter, the exact size of holes, for their whole length.
KENT BUILDING, CHICAGO.
Pond & Pond, Architects; E. C. & R. M. Shankland, Engineers
In this ten-story building, cast-iron columns and steel floor-beams are used. Note connection of girders to columns. They rest on a shelf and have a side support. Note that field connections are bolted. Setting of steel work was started
May 29. 1903. and finished October 1. 1903.
KENT BUILDING. CHICAGO, ILL.
Pond & Pond, Architects; E. C. & R. M. Shankland, Engineer*.
This Picture Shows a Method of Good Fireproof Construction, of Burnt Tile. View Taken Just before Plastering was Done. Pipes Along Ceiling are Part of Sprinkler System; this is Used in Warehouses to Put Out Incipient Fires.
Fig. 198 shows the detail of girder No. 1. This girder receives a terra cotta arch on each side and as the girder beams are deeper than the floor beams, angles must be used to receive the arch. These angles have to be cut to clear the connection angles on the beams framing in, however. The separators must be spaced so as not to interfere with the rivets in the shelf angles.
The student should carefully study every detail shown in the preceding cuts, and should thoroughly understand every feature of them and every note, and the reason for all the special features appearing in them. He should work out for himself all the measurements given by the details so that he will understand these and know just how to proceed in other cases.
2. Make a shop detail of a 12-in., 40-lb. beam, 15 ft. long, framing into a 15-in., 42-lb. beam flush on bottom at one end and into an 18-in., 55-lb. beam 1 in. below the top at the other end. The 12-in. beam has holes for three 8-in., 18-lb. beams with standard connections spaced equally throughout the length, center to center, between girders.
3. Make a shop detail of a 9-in., 21-lb. beam with a 4 X 3 X 3/8-in. angle riveted to the beam the full length. This angle to be placed with the horizontal leg down and as near the bottom of the 9-in. beam as possible, and the 4-in. leg to be out. The beam rests on a wall 8 in. at each end and it is 13 ft. 9 in. between walls.
4. Make a detail covering channels No. 7 and No. 8, shown in Fig. 199.
5. Make a detail of channel No. 17 in Fig. 199.
6. Make a detail of channel No. 10 in Fig. 199.
7. Make details covering the 5 to 8-in. beams, and the 14 to 17-in. beams in Fig. 208.