Plastic Pipe
| POLYETHYLENE DOUBLE WALL CORRUGATED PIPE CULVERT | ||
| DIAMETER (IN) | AREA (SQ FT) |
ALLOWABLE MAXIMUM COVER (FT) |
| 12 | 08 | 21 |
| 15 | 12 | 21 |
| 18 | 18 | 20 |
| 24 | 31 | 20 |
NOTE: For details of bedding for Polyethylene Pipe Culvert see Standard PB-1.
| POLYVINYLCHLORIDE RIBBED PIPE CULVERT | ||
| DIAMETER (IN) | AREA (SQ FT) |
ALLOWABLE MAXIMUM COVER (FT) |
| 18 | 17 | 20 |
| 21 | 23 | 19 |
| 24 | 30 | 19 |
| 30 | 47 | 18 |
| 36 | 69 | 18 |
| 48 | 123 | 18 |
NOTES: Cover heights indicated in tables are for finished construction. To protect pipe during construction, minimum height of cover to be as follows prior to allowing construction traffic to cross installation:
| Pipe Diameter | Minimum Fill height During Construction** |
| 12″ to 30″ | 1″-6″ |
| 36″ and above | Diam 2 |
Minimum finished height of cover to be 1/8 Diam. or 1′-0″, whichever is greater, except pipe under entrances, median crossovers, street and secondary connections where a 9″ minimum will be permitted for pipe up to 24″ diameter.
** The cover shall extend the full length of the pipe. The approach fill is to extend a minimum of (10 x Dia + ½ Dia) on each side of the structure, or to the intersection with a cut.
The allowable fill tables shown are based on a soil modulus of 700 psi. All other design criteria are in accordance with the 1983 AASHTO Specifications and VDOT Modifications for Soil Thermoplastic Pipe Interaction Systems.
PLASTIC PIPE
Source: Virginia Department of Transportation