Handbook of Civil Engineering Calculations

FIGURE 39. Transverse section of composite bridge.

respectively. The superscripts c and n refer to the composite and noncomposite member,
respectively.
The relevant properties of the W36 x 150 are A = 44.16 in
2
(284.920 cm
2
); / - 9012
in
4
(37.511 dm
4
); d = 35.84 in (910.336 mm); S = 503 in
3
(8244.2 cm
3
); flange thickness
= 1 in (25.4 mm), approximately.

2. Compute the section moduli of the noncomposite section
   where the cover plate is present
   To do this, compute the static moment and moment of inertia of the section with respect
   to the center of the W shape; record the results in Table 2. Refer to Fig. 40: y =
   -280/59.16 = ^.73 in (-120.142 mm);y'b = 19.42-4.73 = 14.69 in (373.126 mm);y'ts =
   17.92 + 4.73 = 22.65 in (575.31 mm). By the moment-of-inertia equation, / = 5228 +

TABLE 2. Calculations for Girder with Cover Plate

A y Ay Af I^_

Noncomposite:
W36xl50 44.16 000 9,012
Cover plate 15.00 -18.67 -280 5,228 O
Total 59.16 ... -280 5,228 9,012

Composite, n = 30:

Steel (total) 59.16 -280 5,228 9,012

Slab 16.90 21.17 358 7,574 60

Total 76.06 ... 78 12,802 9,072

Composite, n = 10:

Steel (total) 59.16 -280 5,228 9,012

Slab 50.70 21.17 1,073 22,722 179

Total 109.86 ... 793 27,950 9,191

Haunch