Page 336 - Facility Piping Systems Handbook for Industrial, Commercial, and Healthcare Facilities

SITE UTILITY SYSTEMS

6.58 CHAPTER SIX

TABLE 6.15 Truck Impact Factor

Depth of cover * Impact factor (F)
Up to 1 ft 0 in 1.30
1 ft 1 in to 2 ft 0 in 1 20
2 ft 0 in to 2 ft 11 in 1.10
3 ft 0 in or more 1.00

*
1 ft = 0.3 m

TABLE 6.16 Outside Diameter of Pipe

Outside diameter, ft
Nominal Inside Corrugated
size, area, Nominal Cast Ductile Plain Reinforced steel,
2
in ft I.D., ft iron iron concrete concrete Clay 1/8 in Composite
10 0.545 0.84 0.89 0.93 1.04 — 1.04 0.92 0.94
12 0.785 1.00 1.06 1.10 1.29 1.33 1.25 1.08 1.13
14 1.18 1.18 1.28 — — 1.33
15 1.227 1.25 1.32 1.56 1.62 1.54 1.33 1.44
16 1.53 1.33 — 1.46 — — — — 1.52
18 1.767 1.50 — 1.62 1.87 1.92 1.86 1.58 1.68
20 2.26 1.70 — 1.82 — — — — 1.87
21 2.405 1.75 — 2.20 2.20 2.14 1.83 1.98
24 3.142 2.00 — 2.12 2.62 2.62 2.39 2.08 2.27
27 3.976 2 25 — 2.92 2.92 2.77 2.33 2.55
30 4.909 2.50 — 2.66 3.20 3.20 3.08 2.58 2.84
33 5.940 2.75 — 3.50 3.50 3.31 2.83 3.14
36 7.069 3.00 — 3.19 3.79 3.79 3.66 3.08 3.39

Live Load from Trains. For calculating the live load transmitted to a pipe under a railroad,
refer to Table 6.17. Recommendations of the American Railway Engineering Association
are used. This figure should be added to the weight of the track structure. The following
criteria are used:

1. Copper E72 railroad design load is assumed.
2. The weight of track structure and ballast is assumed to be 200 lb/ft.
3. An impact factor of 1.4 is used, decreasing to 1.0 with 10 ft of cover. The impact factor
has been included in the calculations used to prepare Table 6.17.
Loads from Other Equipment. For calculating the live load transmitted to a pipe from
any other heavy equipment (crane, bulldozer, or others), the total weight of the vehicle must
be found. The weight on each of its tracks or wheels is calculated by dividing the number
of wheels or tracks into the vehicle weight. With the track or wheel weight and the pipe
depth of bury known, refer to Table 6.18 for the percent of load transmitted to the pipe.
The track or wheel weight is then multiplied by the percent load transmitted to calculate
the actual load on the pipe. Regardless of how slowly the vehicle is capable of moving, an
impact factor must be used. The calculated actual load on the pipe is then multiplied by the

Downloaded from Digital Engineering Library @ McGraw-Hill (www.accessengineeringlibrary.com)
Copyright © 2009 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.