DESCRIPTION
607.01.01 General. This work consists of constructing underdrains using pipe , drain backfill, and geotextile .
MATERIALS
607.02.01 General. Material shall conform to the following Subsections and Section:
Portland Cement ................................ .................................................................................................................................... Section 701 Drain Backfill ........................................................................................................................................................... Subsection 704.03.01 Grout and Mortar Aggregate .................................................................................................................................... Subsection 706.03.04 Perforated Concrete Pipe ........................................................................................................................................ Subsection 708.03.02 Clay Pipe ................................................................................................................................................................ Subsection 708.03.03 Corrugated Polyethylene Drainage Pipe ................................ ................................ ............................................. Subsection 708.03.04 (d) Smooth Wall Polyvinyl Chloride Pipe .................................................................................................................. Subsection 708.03.04 (e) Corrugated Steel Pipe for Underdrains ................................ .................................................................................... Subsection 709.03.04 Corrugated Aluminum Pipe for Underdrains ............................................................................................................ Subsection 709.03.05 Engineering Fabrics ................................ ................................ ............................................................................................... Section 731 Underdrain pipe may be corrugated steel, corrugated aluminum, concrete, clay, corrugated polyethylene , or smooth wall polyvinyl chloride pipe. Assemble each separate underdrain installation from one material only. Metal pipe plate wall thickness shall be 1.6 mm (16 gage) for steel and 1.5 mm (16 gage) for aluminum unless otherwise noted on the plans. Submit in writing, 2 weeks in advance of the preconstruction conference, the type of underdrain pipe to be furnished. No changes will be allowed to the type of material chosen. The lengths shown on the plans are approximate. Do not order and deliver the pipe until a correct list of sizes and lengths is furnished by the Engineer. Ship and handle pipes in such a manner as to prevent bruising, scaling, or breaking. Repair any damaged galvanized coating according to Subsection 604.02.01. Do not lay any pipe which is cracked, checked, spalled, or damaged. CONSTRUCTION
607.03.01 Earthwork. Excavation and drain backfill shall conform to Sections 206 and 209 respectively with the
following modifications:
a.Excavate trenches to the dimensions and grade required.
b.Place geotextile at locations shown on the plans and in accordance with Section 610.
c.Place a minimum 75 mm (3 in.) bedding layer of drain backfill material in the bottom of the trench for its full width and length, and bring to a uniform grade.
d.If an item for grouting drain backfill is shown in the proposal, cover drain backfill with a thick grout not less than 25 mm (1 in.) in thickness. Compose the grout of 1 part Portland cement and 5 parts grout aggregate, by volume. Mix grout materials to a suitable consistency. Use grout within 30 minutes after the addition of water. Thoroughly tamp grout to provide an impervious layer over the entire surface of the drain backfill.
607.03.02 Laying Pipes. Lay bell and spigot concrete or clay pipe upgrade with the bell end upgrade and the
spigot end not quite fully entered in the adjacent bell. Lay pipe true to line and grade with a uniform bearing under the full length of the barrel. Cover the pipe joints with 2 ply tar paper strips not less than 150 mm (6 in.) in width and of sufficient length to permit the ends to be turned outward and laid flat on the bottom course of drain backfill on either side of the pipe f or a distance of 75 mm (3 in.). When pipe does not have perforations around the full circumference, lay with the perforations at the bottom of the pipe. Firmly bed the pipe throughout its length. 607 UNDERDRAINS Join metal pipe sections with band couplers. Join corrugate d polyethylene pipe sections by snap couplers, split couplers , or spin- on couplers as recommended by the manufacturer. Join concrete and clay pipe sections with external bands of mortar placed around the pipe joints as herein specified. Join several secti ons of pipe before commencing banding operations, but do not let the placing of external bands be more than 5 lengths of pipe behind joining operations. Immediately in advance of placing external band mortar, thoroughly clean and wet the external surface of the pipe sections at the joint to insure proper bonding of the band mortar with the pipe. Exercise care to make a union between the band and the mortar which was placed under the joint before the pipe sections were abutted. Make the band not less tha n 13 mm (0.5 in.) thick at the pipe joint and approximately 100 mm (4 in.) wide, overlapping the abutting ends of the pipe sections approximately 50 mm (2 in.). The edges of the band shall adhere to the pipe surface to prevent peeling. Finish in a workmanlike manner. Lay pipe with all ends firmly joined. Install joints such that the connection of pipe sections form a continuous line free of irregularities in the flow line. After inspection and approval of the pipe installation, backfill the trench. METHOD O F MEASUREMENT
607.04.01 Measurement. Quantities shown on the plans are based on corrugated metal pipe. No adjustment of
quantities will be made due to use of other types of pipe. Underdrain pipe will be measured by the linear meter (linear foot). Bends, wyes, tees, and other branches will be measured as pipe along centerlines to the point of intersection. Grouted drain backfill will be measured by the linear meter (linear foot) along the longitudinal axis of the drain. Structure excavation, drain backfill , and geotextile will be measured and paid for as separate items as provided in Sections 206, 209, and 610. BASIS OF PAYMENT
607.05.01 Payment. The accepted quantities, measured as provided above, will be paid for at the contract
price per unit of measurement for the pay items listed below that are shown in the proposal. Payment will be full compensation for the work prescribed in this Section. Provide for handling whatever water is encountered at the site with no additional compensation a llowed therefore. Payment will be made under: Pay Item Pay Unit (size) Perforated Pipe ...................................................................................................................................... Linear Meter (Linear Foot) (size) Nonperforated Pipe ................................ ................................................................................................ Linear Meter (Linear Foot) Grouting Drain Backfill (width) ................................ ................................ .......................................................... Linear Meter (Linear Foot) SECTION 608 DOWNDRAINS DESCRIPTION
608.01.01 General. This work consists of furnishing and installing embankment protectors, downdrain pipe,
anchor assemblies, metal end sections , geotextile, and riprap. Lengths of downdrain pipe shown on the plans are approximate. Do not order and deliver the downdrain pipe until it is staked in the field and a list of lengths and pipe angles is furnished by the Engineer. MATERIALS
608.02.01 General. Material shall conform to the following Sections and Subsections :
Portland Cement Concrete ................................ ..................................................................................................................... Section 501 Reinforcing Steel ................................ .................................................................................................................................... Section 505 Riprap .................................................................................................................................................................................... Section 610 Smooth Wall Polyethylene Pipe ......................................................................................................................... Subsection 708.03.04 (a) Corrugated Polyethylene Pipe ................................ ................................ ............................................................ Subsection 708.03.04 (b) Corrugated Steel Pipe ............................................................................................................................................. Subsection 709.03.01 Corrugated Aluminum Pipe ..................................................................................................................................... Subsection 709.03.02 Anchor Assemblies for Downdrains ................................ ......................................................................................... Subsection 709.03.03 Geotextile (Class 2) ................................ ................................................................................................................. Subsection 731.03.03 Downdrain pipe may be corrugated steel, corrugated aluminum, or one of the plastic types specified above. Metal pipe plate thickness shall be 1.6 mm (16 gage) for steel and 1.5 mm (16 gage) for aluminum unless otherwise noted on the plans. Except as hereinafter provided, assemble each separate downdrain installation from one material only. Electrically insu late anchor assemblies used with an aluminum installation. Connect plastic pipe to metal end sections according to the manufacturer’s recommendations. Repair any damaged galvanized coating on corrugated steel parts according to Subsection 604.02.01. Metal end sections shall conform to the details and dimensions shown in the plans and, except for shape, shall conform to the requirements for corrugated metal pipe. Metal grates and frames shall conform to Section 609. CONSTRUCTION
608.03.01 General. Structure excavation and backfill shall conform to Sections 206 and 207.
Construct concrete inlet structures according to Sections 501 and 502. Construct riprap apron as shown on the plans. Connect metal pipe sections by means of band couplers. Connect plastic pipe sections according to Section 605. METHOD OF MEASUREMENT
608.04.01 Measurement. Embankment protectors, metal end sections, and anchor assemblies will be
measured by the each. Downdrain pipe will be measured by the linear meter (linear foot) . Structural steel grates for embankment protectors will be measured and paid for according to Section 609.
Source: Nevada Standard Specifications for Road and Bridge Construction, 2014 Edition. Pages 335–336 of 610.