Appendix A: Design Procedure for Riprap Armor
Table A.1. Gradations for Riprap Placement in the Dry, Low-Turbulence Zones
Limits of Stone Weight, lb1, for Percent Lighter by Weight
D100(max)
100
50
15
D30(min)
D90(min)
(in.)
(ft)
(ft)
Max2
Max2
Max
Min
Min
Min
Specific Weight = 155 pcf
12
81
32
24
16
12
5
0.48
0.70
15
159
63
47
32
23
10
0.61
0.88
18
274
110
81
55
41
17
0.73
1.06
21
435
174
129
87
64
27
0.85
1.23
24
649
260
192
130
96
41
0.97
1.40
27
924
370
274
185
137
58
1.10
1.59
30
1,268
507
376
254
188
79
1.22
1.77
33
1,688
675
500
338
250
105
1.34
1.94
36
2,191
877
649
438
325
137
1.46
2.11
42
3,480
1,392
1,031
696
516
217
1.70
2.47
48
5,194
2,078
1,539
1,039
769
325
1.95
2.82
54
7,396
2,958
2,191
1,479
1,096
462
2.19
3.17
Specific Weight = 165 pcf
12
86
35
26
17
13
5
0.48
0.70
15
169
67
50
34
25
11
0.61
0.88
18
292
117
86
58
43
18
0.73
1.06
21
463
185
137
93
69
29
0.85
1.23
24
691
276
205
138
102
43
0.97
1.40
27
984
394
292
197
146
62
1.10
1.59
30
1,350
540
400
270
200
84
1.22
1.77
33
1,797
719
532
359
266
112
1.34
1.96
36
2,331
933
691
467
346
146
1.46
2.11
42
3,704
1,482
1,098
741
549
232
1.70
2.47
48
5,529
2,212
1,638
1,106
819
346
1.95
2.82
54
7,873
3,149
2,335
1,575
1,168
492
2.19
3.17
Specific Weight = 175 pcf
12
92
37
27
18
14
5
0.48
0.70
15
179
72
53
36
27
11
0.61
0.88
18
309
124
92
62
46
19
0.73
1.06
21
491
196
146
98
73
31
0.85
1.23
24
733
293
217
147
109
46
0.97
1.40
27
1,044
417
309
209
155
65
1.10
1.59
30
1,432
573
424
286
212
89
1.22
1.77
33
1,906
762
565
381
282
119
1.34
1.94
36
2,474
990
733
495
367
155
1.46
2.11
42
3,929
1,571
1,164
786
582
246
1.70
2.47
48
5,864
2,346
1,738
1,173
869
367
1.95
2.82
54
8,350
3,340
2,474
1,670
1,237
522
2.19
3.17
1
Stone weight limit data from ETL 1110-2-120 (HQUSACE, 1971 (14 May) "Additional Guidance for
Riprap Channel Protection, encl. 1," U.S. Government Printing Office, Washington, DC). Relationship
between diameter and weight is based on the shape of a sphere.
2
The maximum limits at the W50 and W15 sizes can be increased as in the Lower Mississippi Valley Division
Standardized Gradations shown in EM 1110-2-1601.
A-8
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