PIPE UNDERDRAINS
PART 1 GENERAL
1.1SECTION INCLUDES
A.Pipe underdrains.
1.2RELATED SECTIONS
A.Section 02056: Embankment, Borrow, and Backfill
B.Section 02075: Geotextiles
C.Section 02317: Structural Excavation
D.Section 02633: Concrete Drainage Structures
1.3REFERENCES
A.AASHTO M 252: Corrugated Polyethylene Drainage Pipe
B.AASHTO M 278: Class PS46 Poly (Vinyl Chloride) (PVC) Pipe
C.AASHTO M 294: Corrugated Polyethylene Pipe, 300-to 1500-mm (12- to
60-in.) Diameter
D.AASHTO M 304: Poly (Vinyl Chloride) (PVC) Profile Wall Drain Pipe and
Fittings Based on Controlled Inside Diameter
E.AASHTO M 330: Polypropylene Pipe, 300- to 1500-mm (12- to 60-in.)
Diameter
F.AASHTO PP 63: Pipe Joint Selection for Highway Culvert and Storm
Drains
G.AASHTO National Transportation Product Evaluation Program (NTPEP)
Pipe Underdrains
1.4DEFINITIONS
A.Profile Wall Pipe – A pipe that has a smooth interior wall with an exterior
that is either is ribbed, corrugated, or smooth. The wall may contain hollow cores.
1.5SUBMITTALS
A.Manufacturer’s product data sheets and installation instructions for
information.
B.Documentation from AASHTO NTPEP showing compliance with Table 1
for the pipe material and diameter supplied for information.
PART 2 PRODUCTS
2.1PIPE
A.Thermoplastic profile wall pipe having perforations around the entire
circumference meeting the material requirements shown in Table 1.
Table 1 Perforated Pipe Material Specifications Material Type AASHTO Specification High Density Polyethylene (HDPE) M 252, M 294 Polyvinyl Chloride (PVC) M 278, M 304 Polypropylene M 330
B.Soil tight pipe joints according to AASHTO PP 63.
C.Pipe fittings matching the pipe material type.
2.2DRAINAGE GEOTEXTILE
A.Refer to Section 02075.
2.3FREE DRAINING GRANULAR BACKFILL
A.Refer to Section 02056.
Pipe Underdrains
PART 3 EXECUTION
3.1INSTALLATION
A.Excavate a trench to a width of the outside pipe diameter plus 2 ft and to a
depth of 3 inch below the bottom of the pipe.
1.Refer to Section 02317.
2.Keep trenches free of water.
B.Grade and prepare the bottom of the trench to provide a firm and uniform
bearing surface.
C.Place drainage geotextile within the trench as shown.
D.Place and compact the bottom 3 inch of the trench with free draining
granular backfill.
E.Connect pipes to concrete drainage structures according to Section
02633.
1.Place an end cap at the upstream end of the pipe when not
connected to a structure.
F.Place and compact the remainder of the free draining granular backfill to
depth shown.
END OF SECTION
Pipe Underdrains
Pipe Underdrains in other states
Utah revises spec sections through supplementals and new editions. We check this one every week and email you the day it changes. Free, no account.
Source: Utah Standard Specifications for Road and Bridge Construction, 2026 Edition. Pages 388–390 of 1,331.
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