Document 37LqBB3Ry28Y42dM90ydX4Qo0
Johns-Manville Sales Corporation
Pipe Division
Greenwood Plaza Denver, Colorado 80217 (303)770-1000
PLAINTIFF'S EXHIBIT CAP-1070
January 5, 1976
Mr. A. I. Leff Certain-Teed Products Corporation P.O. Box 860 Valley Forge, PA 19482
RE: AACPP - AD HOC COMMITTEE ON SEWER PIPE REDESIGN HEIGHT OF COVER DESIGN LIMITS FOR CONCRETE PIPE PER ASTM C-76 and C-14
Dear A1:
In response to my assignment, I an attaching the design heights of cover for concrete pipe per ASTM C-76 and C-14 as recommended by the American Concrete Pipe Association. Table 1 lists values for ASTM C-76 pipe while Table 2 lists the same results for ASTM C-14 pipe. On each Table there are two (2) height of cover values listed. One represents a soil unit weight of 100 lb/ft^ and the other in parenthesis represents a unit weight of 120 lb/ft3.
Note the dependence of the C-14 pipe depths on size while those for C-76 pipes are independent of size. It is 'also noted that the Concrete Pipe Design Manual uses an rSp = -0.5 to calculate the transition width load while our J-M sewer pipe manual uses rs<jp = +0.7.
A L. UaUlULLCM U9
cc: Frank T. Duffy H. Fraser W. R. Perrell J. Jackson File (2)
Flintkote
r.Aonn .icm ahoa ccc
TABLE 1. HEIGHT OF COVER LIMITS FOR C-76 REINFORCED CONCRETE PIPE*
Soil Unit Weight (lb/ft3)'
100
120
Height of Cover Desiqn Limit (Ft)
Class II
Class III
Class IV
Class V
7-8
10-11
15-16
22-24
5-6
8-9
12-13
17-19
* Assumes 0.01 crack three-edge bearing loads with a safetyfactor of 1.0 and Class C bedding, Lf = 1.5.
Based on transition width loads contained in the Concrete Pipe Design Manual calculated from K0.19 rscP = -0.5 and 3* = 100 lb/ft3 and / = 120 lb/ft
CAPCO JEN 0024.557
TABLE 2. HEIGHT OF COVER LIMITS FOR C-14 CONCRETE SEWER PIPE*
Size 6 8
10 12 15 18 21 24 27 30 33 36
Height of Cover Limits for w = 100 lb/ft3 (120 lb.ft3) in Feet
Class I
Class II
Class III
15 (12) 12 (9) 10 (8)
21 (17) 16 (13) 13 (ID
25 (20) 19 (15) 16 (13)
9 (8)
11 (10)
13 (ID
8 (7)
10 (9)
11 (10)
7 (6)
10 (9)
11 (10)
7 (5) .
10 (8)
11 (9)
7 (5)
9 (7)
11 (9)
6 (5)
9 (7)
11 (9)
6 (5)
8 (6)
10 (8)
6 (5)
8 (6)
9 (8)
6 (5)
8 (6)
8 (7)
* Assumes Class C bedding I.f = 1.5 and safety factor SF = 1.5.
Based on Concrete Pipe Design Manual tran sition width loads, calculated from I<^ = 0.19 rsdP = -0.5 7T = 100 lb/ft3 and (120 lb/ft3).
i' i
CAPCO JEN 0024-558