STRUCTURAL ANALYSIS
5th Edition
Kenneth M. Leet, Chia-Ming Uang, Joel T. Lanning, and Anne M. Gilbert
SOLUTIONS MANUAL
CHAPTER 2: DESIGN LOADS AND
STRUCTURAL FRAMING
2-1
Copyright © 2018 McGraw-Hill Education. All rights reserved.
No reproduction or distribution without the prior written consent of McGraw-Hill Education.
, P2.1. Determine the deadweight of a 1-ft-long 72ʺ
segment of the prestressed, reinforced concrete 6ʺ
tee-beam whose cross section is shown in 6ʺ
Figure P2.1. Beam is constructed with 48ʺ 8ʺ 24ʺ
3
lightweight concrete which weighs 120 lbs/ft .
12ʺ
18ʺ
Section
P2.1
Compute the weight/ft. of cross section @ 120 lb/ft3.
Compute cross sectional area:
æ1 ö
Area = (0.5¢ ´6 ¢) + 2 çç ´ 0.5¢ ´ 2.67 ¢÷÷ + (0.67¢ ´ 2.5¢) + (1.5¢ ´1¢)
çè 2 ÷ø
= 7.5 ft 2
Weight of member per foot length:
wt/ft = 7.5 ft 2 ´120 lb/ft 3 = 900 lb/ft.
2-2
Copyright © 2018 McGraw-Hill Education. All rights reserved.
No reproduction or distribution without the prior written consent of McGraw-Hill Education.
, P2.2. Determine the deadweight of a 1-ft-long three ply felt
2ʺ insulation tar and gravel 3/4ʺ plywood
segment of a typical 20-in-wide unit of a roof
supported on a nominal 2 × 16 in. southern pine
beam (the actual dimensions are 12 in. smaller).
2
The 43 -in. plywood weighs 3 lb/ft . 1 1/2ʺ 15 1/2ʺ
20ʺ 20ʺ
Section
P2.2
See Table 2.1 for weights
wt / 20 ¢¢ unit
20 ¢¢
Plywood: 3 psf ´ ´1¢ = 5 lb
12
20 ¢¢
Insulation: 3 psf ´ ´1¢ = 5 lb
12
20 ¢¢ 9.17 lb
Roof’g Tar & G: 5.5 psf ´ ´1¢ =
12 19.17 lb
¢¢
lb (1.5¢¢ ´15.5) ´1¢ = 5.97 lb
Wood Joist = 37 3
ft 14.4 in 2 / ft 3
Total wt of 20 ¢¢ unit = 19.17 + 5.97
= 25.14 lb. Ans.
2-3
Copyright © 2018 McGraw-Hill Education. All rights reserved.
No reproduction or distribution without the prior written consent of McGraw-Hill Education.