13.1general

Double-tee connections utilize T-stub components that are bolted to both the column flange and the beam flanges using high-strength bolts. Either four bolts or eight bolts attach the T-stub components to the column flanges. The top and bottom T-stubs shall be identical. T-stubs shall be cut from rolled sections. The beam web is connected to the column with a bolted single-plate shear connection. A detail for this connection is shown in Figure 13.1. Yielding and hinge formation are intended to occur in the beam near the ends of the stems of the T-stubs. Figures 13.2 through 13.6 provide details regarding the dimensioning notation used in this chapter.

Figure description:

Figure 13.1: Typical double-tee connection

Key Components and Features:

• Structural Members: Vertical column connected to a horizontal beam using a double-tee configuration.
• T-Stub Components: Top and bottom T-sections consisting of a T-flange (bolted to the column and a T-stem (bolted to the beam flange.))
• Bolting System:
  • Tension bolts: Connect T-flanges to the column flange.
  • Shear bolts: Connect T-stems to the beam flanges.
  • Web bolts: Secure the beam web to the column via a shear plate.
• Support Plates: Continuity plates installed within the column's web area aligned with the T-flanges.
• Adjustments: Finger shims and standard shims are indicated for use between connecting surfaces if required.

Fig. 13.1. Typical double-tee connection.

Figure description:

The image illustrates beam dimensions for double-tee structural connections.

Key Dimensions:

• $L_o$: Overall length between column centers.
• $L_f$: Clear span between column faces.
• $L_h$: Distance between the centers of the plastic hinge regions.
• $S_h$: Distance from the column face to the center of the plastic hinge.
• $S_1$: Distance from the column face to the first row of bolts.
• $SB$: Setback distance from the column face to the end of the beam.
• $L_{vb}$: Length of the vertical bolt group.
• $L_{ehb}$: Edge distance for horizontal bolts.

Key Components:

• Double-Tee Connectors: Bolted to the beam flanges and column faces.
• Shear Tab: Bolted to the beam web at each end.
• Plastic Hinges: Shaded areas located in the beam web and flanges near the connections.
• Structural Columns: I-beam sections at both ends supporting the central beam.

Fig. 13.2. Beam dimensions for double-tee connections. Shaded regions represent plastic hinges.

Figure description:

Key Information: Column and Shear Plate Dimensions (Fig. 13.3

The image details structural dimensions for double-tee connections in two configurations: 4 Tension Bolts and 8 Tension Bolts.

Key Entities and Parameters:

• Column Tension Bolt Layout:
  • $d_{thc}$: Diameter of tension bolt holes in the column.
  • $g_{tb}$: Vertical gauge distance between tension bolt rows.
  • $g_{ic}$: Horizontal gauge distance between inner columns of bolts.
• Shear Plate Dimensions:
  • $L_{sp}$: Total height/length of the shear plate.
  • $t_{sp}$: Thickness of the shear plate.
  • $L_{ehsp}$: Horizontal edge distance from the bolt centerline to the plate edge.
  • $L_{evsp}$: Vertical edge distance from the top/bottom bolts to the plate edge.
  • $e_x$: Horizontal distance from the column face to the centerline of the shear plate bolts.
• Web Bolt Layout:
  • $d_{whsp}$: Diameter of web bolt holes in the shear plate.
  • $S_{wb}, \text{typ.}$: Typical vertical spacing between bolts in the shear plate.

Fig. 13.3. Column and shear plate dimensions for double-tee connections.