Are there standard sizes of pipe arch, and if so, what are they?
A pipe arch is a culvert with a flattened (but not completely flat) bottom. The culvert has three radii, a large one on the bottom, a small one in the bottom corners, and a normal one in the upper half.
In my experience pipe arches do not have a high service life because of high deformations. The bottom corner requires very high compaction effort to limit the deformations over time, or you can try two corrugated steel pipes. There are usually multiple options.
ASTM A760 is the standard that governs the manufacture of corrugated steel pipe, and the pipe arch sizes are defined as follows:
| Pipe Arch Size (in.) | Cross-sectional Area (ft2) | Springline Rise, B (ft) | Top Radius (ft) | Bottom Corner Radius (ft) | Bottom Radius (ft) |
|---|---|---|---|---|---|
| 17 x 13 | 1.1 | 4 1/8 | 8 5/8 | 3 1/2 | 25 5/8 |
| 21 x 15 | 1.6 | 4 7/8 | 10 3/4 | 4 1/8 | 33 1/8 |
| 20 x 16 | 1.7 | 5 1/8 | 10 1/4 | 5 | 27 1/2 |
| 23 x 19 | 2.3 | 5 7/8 | 11 5/8 | 5 3/8 | 34 1/4 |
| 24 x 18 | 2.2 | 5 5/8 | 11 7/8 | 4 7/8 | 34 5/8 |
| 27 x 21 | 3.0 | 6 3/4 | 13 1/2 | 5 3/4 | 40 7/8 |
| 28 x 20 | 2.9 | 6 1/2 | 14 | 5 1/2 | 42 1/4 |
| 33 x 26 | 4.7 | 8 3/4 | 16 5/8 | 7 1/8 | 51 3/8 |
| 35 x 24 | 4.5 | 8 1/8 | 17 7/8 | 6 7/8 | 55 1/8 |
| 40 x 31 | 6.7 | 10 3/8 | 20 1/4 | 8 3/8 | 62 1/2 |
| 42 x 29 | 6.5 | 9 3/4 | 21 1/2 | 8 1/4 | 66 1/8 |
| 46 x 36 | 9.2 | 12 3/8 | 23 1/4 | 9 3/4 | 73 |
| 49 x 33 | 8.9 | 11 3/8 | 25 1/8 | 9 5/8 | 77 1/4 |
| 53 x 41 | 11.7 | 15 1/4 | 28 1/16 | 10 3/16 | 73 7/16 |
| 57 x 38 | 11.6 | 13 | 28 5/8 | 11 | 88 1/4 |
| 60 x 46 | 15.6 | 20 1/2 | 29 3/8 | 18 3/4 | 51 1/8 |
| 64 x 43 | 14.7 | 14 5/8 | 32 1/4 | 12 3/8 | 99 1/4 |
| 66 x 51 | 19.3 | 22 3/4 | 32 5/8 | 20 3/4 | 56 1/4 |
| 71 x 47 | 18.1 | 16 1/4 | 35 3/4 | 13 3/4 | 110 1/4 |
| 73 x 55 | 23.2 | 25 1/8 | 36 3/4 | 22 7/8 | 63 3/4 |
| 77 x 52 | 21.9 | 17 7/8 | 39 3/8 | 15 1/8 | 121 1/4 |
| 81 x 59 | 27.4 | 23 3/4 | 39 1/2 | 20 7/8 | 82 5/8 |
| 83 x 57 | 26.0 | 19 1/2 | 43 | 16 1/2 | 132 1/4 |
| 87 x 63 | 32.1 | 25 3/4 | 43 3/8 | 22 5/8 | 92 1/4 |
| 95 x 67 | 37.0 | 27 3/4 | 47 | 24 3/8 | 100 1/4 |
| 103 x 71 | 42.4 | 29 3/4 | 51 1/4 | 26 1/8 | 111 5/8 |
| 112 x 75 | 48.0 | 31 5/8 | 54 7/8 | 27 3/4 | 120 1/4 |
| 117 x 79 | 54.2 | 33 5/8 | 59 3/8 | 29 1/2 | 131 3/4 |
| 128 x 83 | 60.5 | 35 5/8 | 63 1/4 | 31 1/4 | 139 3/4 |
| 137 x 87 | 67.4 | 37 5/8 | 67 3/8 | 33 | 149 1/2 |
| 142 x 91 | 74.5 | 39 1/2 | 71 5/8 | 34 3/4 | 162 3/8 |
Although not included in the ASTM standard, the industry felt the need for a few larger sizes, and as a result the following are widely available:
| Pipe Arch Size (in.) | Cross-sectional Area (ft2) | Largest Horizontal Dimension, B (ft) | Top Radius (ft) | Bottom Corner Radius (ft) | Bottom Radius (ft) |
|---|---|---|---|---|---|
| 150 x 96 | 81 | 41 | 76 | 36 | 172 |
| 157 x 101 | 89 | 43 | 80 | 38 | 180 |
| 164 x 105 | 98 | 45 | 82 | 40 | 184 |
| 171 x 110 | 107 | 47 | 85 | 41 | 190 |
Speak Your Mind