Standard Installations and Fill Height Tables
Construction Sequence:
1. Place bedding material to grade. Do not compact bedding under pipe invert. (Do/3)
2. Compact outer bedding.
3. Install pipe to line and grade.
4. Place and compact the haunch area up to the springline.
5. Complete backfill according to specifications.


Trench or Embankment Installation              

Notes:
-All pipe shall be protected during construction by three feet of cover. Slopes of approach ramps shall not exceed one foot in six feet.
-Parallel culvert lines shall be installed with a minimum center to center distance between pipelines of not less than Do + 12", or the outer width of the precast aprons.
-Design methods can be found in ACPA D.D. 40.
-Type 2 installation may require job site inspection and soil testing.
-Designs in excess of 60D are available for special installations.
 
 
BEDDING AND COMPACTION REQUIREMENTS
Installation Type Compaction Requirements for haunch, outer bedding and lower side fill
Standard Proctor %
AASHTO T99		 Modified Proctor Density %
AASHTO T180
Gravelly Sand Sandy-Silt Silty Clay Gravelly Sand Sandy-Silt Silty Clay
SP,GP,SW,GW ML CL SP,GP,SW,GW ML CL
Type 1 95 N/A N/A 90 95 100
Type 2 90 95 N/A 85 90 95
Type 3 85 90 95 85 90 95
Type 4 No Compaction Required No Compaction Required 85 No Compaction Required No Compaction Required 85

 

Maximum Overfill (ft.)
HS20 Live Loads Included
Pipe Size
(Inches)		 Installation Type 2 Installation Type 3 Installation Type 4
Pipe Class Pipe Class Pipe Class
2 3 4 5 40D 50D 60D 2 3 4 5 40D 50D 60D 2 3 4 5 40D 50D 60D
12-15 - - - 42 50 * * - - - 33 44 50 * - - - 22 31 38 45
18-33 - 19 28 42 50 * * - 14 21 33 44 50 * - 10 15 23 31 39 47
36-66 13 18 27 41 50 * * 9 13 21 32 44 50 * 7 9 15 23 32 40 47
72-120 12 18 26 40 50 * * 9 13 20 32 43 50 * 6 8 15 23 32 40 47
* Fill heights determined upon request. Please contact your state office for more information.

DISCLAIMER
The successful application and use of the Cretex Fill Height Tables is dependent on the application of skilled engineering judgment supplied by the pipeline designer. The tabulated fill height values have been selected by the Cretex Company based on standard pipe designs with verifiable test strengths. Pipelines must be installed according to details on this drawing and those specified in the American Association of Highway and Transportation Officials’ (AASHTO), LRFD Bridge Design Specifications. The designer must be familiar with local soil types and pipe installation methods before making the proper selection of concrete pipe strength.
 

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