USACE / NAVFAC / AFCESA / NASA UFGS-33 46 16 (April 2008) -------------------------- Preparing Activity: USACE Superseding UFGS-33 46 16 (July 2006) UNIFIED FACILITIES GUIDE SPECIFICATIONS References are in agreement with UMRL dated January 2009 SECTION 33 46 16 SUBDRAINAGE SYSTEM 04/08 NOTE: This guide specification covers the requirements for subdrainage systems for drainage of water from under the ground. Edit this guide specification for project specific requirements by adding, deleting, or revising text. For bracketed items, choose applicable items(s) or insert appropriate information. Remove information and requirements not required in respective project, whether or not brackets are present. Comments and suggestions on this guide specification are welcome and should be directed to the technical proponent of the specification. A listing of technical proponents, including their organization designation and telephone number, is on the Internet. Recommended changes to a UFGS should be submitted as a Criteria Change Request (CCR). PART 1 GENERAL 1.1 MEASUREMENT AND PAYMENT NOTE: When filter fabric is not used in the drainage system, the requirement for filter fabric will be deleted from this specification. The paragraph as written contemplates taking bids on a unit-price basis. When it is determined that a lump-sum contract may be more advisable, the paragraph will be deleted. 1.1.1 Pipe Subdrains The length of pipe installed will be measured from end to end along the centerlines without any deduction for the diameter of the manholes. Pipe will be paid for according to the number of linear meters feet of subdrains placed in the accepted work. Payment for bedding and filter materials, except filter fabric, will be included in the payment for the pipe subdrain system. 1.1.2 Blind or French Drains Blind or french drains will be paid for by the linear meter footand measured from end to end along the centerlines of the completed drains. 1.1.3 Manholes Manholes to be paid for will be the number of manholes completed with base, rungs or ladders, frames, and covers or gratings (where specified) constructed in the accepted work. 1.1.4 Flushing and Observation Risers Flushing and observation risers to be paid for will be the number of flushing and observation risers completed with frames and covers (where specified) constructed in the accepted work. 1.1.5 Filter Fabric Filter fabric shall be measured for payment by the square [meter yard] [meter foot] in place. Overlapped joints and seams shall be measured as a single layer of cloth. 1.2 REFERENCES NOTE: This paragraph is used to list the publications cited in the text of the guide specification. The publications are referred to in the text by basic designation only and listed in this paragraph by organization, designation, date, and title. Use the Reference Wizard's Check Reference feature when you add a RID outside of the Section's Reference Article to automatically place the reference in the Reference Article. Also use the Reference Wizard's Check Reference feature to update the issue dates. References not used in the text will automatically be deleted from this section of the project specification when you choose to reconcile references in the publish print process. The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only. AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS (AASHTO)AASHTO M 190(2004) Bituminous Coated Corrugated Metal Culvert Pipe and Pipe ArchesAASHTO M 252(2008) Corrugated Polyethylene Drainage PipeAASHTO M 294(2008) Standard Specification for Corrugated Polyethylene Pipe, 300- to 1500-mm DiameterASTM INTERNATIONAL (ASTM)ASTM A 123/A 123M(2008) Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel ProductsASTM A 227/A 227M(2006) Standard Specification for Steel Wire, Cold-Drawn for Mechanical SpringsASTM A 229/A 229M(1999; R 2005) Standard Specification for Steel Wire, Oil-Tempered for Mechanical SpringsASTM A 27/A 27M(2008) Standard Specification for Steel Castings, Carbon, for General ApplicationASTM A 47/A 47M(1999; R 2004) Standard Specification for Steel Sheet, Aluminum-Coated, by the Hot-Dip ProcessASTM A 48/A 48M(2003; R 2008) Standard Specification for Gray Iron CastingsASTM A 760/A 760M(2006) Standard Specification for Corrugated Steel Pipe, Metallic-Coated for Sewers and DrainsASTM A 762/A 762M(2008) Standard Specification for Corrugated Steel Pipe, Polymer Precoated for Sewers and DrainsASTM B 745/B 745M(1997; R 2005) Standard Specification for Corrugated Aluminum Pipe for Sewers and DrainsASTM C 139(2005) Standard Specification for Concrete Masonry Units for Construction of Catch Basins and ManholesASTM C 14(2007) Standard Specification for Concrete Sewer, Storm Drain, and Culvert PipeASTM C 14M(2007) Standard Specification for Concrete Sewer, Storm Drain, and Culvert Pipe (Metric)ASTM C 150(2007) Standard Specification for Portland CementASTM C 231(2008c) Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure MethodASTM C 33(2007) Standard Specification for Concrete AggregatesASTM C 4(2004; R 2005) Clay Drain Tile and Perforated Clay Drain TileASTM C 412(2005a) Concrete Drain TileASTM C 412M(2005a) Concrete Drain Tile (Metric)ASTM C 425(2004) Standard Specification for Compression Joints for Vitrified Clay Pipe and FittingsASTM C 444(2003) Perforated Concrete PipeASTM C 444M(2003) Perforated Concrete Pipe (Metric)ASTM C 478(2008) Standard Specification for Precast Reinforced Concrete Manhole SectionsASTM C 478M(2008e1) Standard Specification for Precast Reinforced Concrete Manhole Sections (Metric)ASTM C 55(2006e1) Concrete BrickASTM C 62(2008) Building Brick (Solid Masonry Units Made from Clay or Shale)ASTM C 654(2005a) Porous Concrete PipeASTM C 654M(2005a) Porous Concrete Pipe (Metric)ASTM C 700(2007a) Standard Specification for Vitrified Clay Pipe, Extra Strength, Standard Strength, and PerforatedASTM D 1751(2004; R 2008) Standard Specification for Preformed Expansion Joint Filler for Concrete Paving and Structural Construction (Nonextruding and Resilient Bituminous Types)ASTM D 1752(2004a; R 2008) Standard Specification for Preformed Sponge Rubber Cork and Recycled PVC ExpansionASTM D 2751(2005) Standard Specification for Acrylonitrile-Butadiene-Styrene (ABS) Sewer Pipe and FittingsASTM D 3034(2008) Standard Specification for Type PSM Poly(Vinyl Chloride) (PVC) Sewer Pipe and FittingsASTM D 3212(2007) Standard Specification for Joints for Drain and Sewer Plastic Pipes Using Flexible Elastomeric SealsASTM D 3753(2005e1) Glass-Fiber-Reinforced Polyester Manholes and WetwellsASTM D 422(1963; R 2007) Particle-Size Analysis of SoilsASTM D 5034(2008) Breaking Strength and Elongation of Textile Fabrics (Grab Test)ASTM F 405(2005) Corrugated Polyethylene (PE) Tubing and FittingsASTM F 667(2006) Large Diameter Corrugated Polyethylene Pipe and FittingsASTM F 758(1995; R 2007e1) Smooth-Wall Poly(Vinyl Chloride) (PVC) Plastic Underdrain Systems for Highway, Airport, and Similar DrainageASTM F 949(2006a) Poly(Vinyl Chloride) (PVC) Corrugated Sewer Pipe with a Smooth Interior and Fittings1.3 SUBMITTALS NOTE: Review submittal description (SD) definitions in Section 01 33 00 SUBMITTAL PROCEDURES and edit the following list to reflect only the submittals required for the project. Submittals should be kept to the minimum required for adequate quality control. A “G” following a submittal item indicates that the submittal requires Government approval. Some submittals are already marked with a “G”. Only delete an existing “G” if the submittal item is not complex and can be reviewed through the Contractor’s Quality Control system. Only add a “G” if the submittal is sufficiently important or complex in context of the project. For submittals requiring Government approval on Army projects, a code of up to three characters within the submittal tags may be used following the "G" designation to indicate the approving authority. Codes for Army projects using the Resident Management System (RMS) are: "AE" for Architect-Engineer; "DO" for District Office (Engineering Division or other organization in the District Office); "AO" for Area Office; "RO" for Resident Office; and "PO" for Project Office. Codes following the "G" typically are not used for Navy, Air Force, and NASA projects. Choose the first bracketed item for Navy, Air Force and NASA projects, or choose the second bracketed item for Army projects. Government approval is required for submittals with a "G" designation; submittals not having a "G" designation are for [Contractor Quality Control approval.] [information only. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government.] Submit the following in accordance with Section 01 33 00 SUBMITTAL PROCEDURES: _{SD-04 Samples Filter Fabric Pipe for Subdrains} Samples of filter fabric, pipe, and pipe fittings, before starting the work. _{SD-07 Certificates Filter Fabric Pipe for Subdrains} Certifications from the manufacturers attesting that materials meet specification requirements. Certificates are required for drain pipe, drain tile, fittings, and filter fabric. 1.4 DELIVERY, STORAGE, AND HANDLING 1.4.1 Delivery and Storage NOTE: This time restriction applies to pipe containing normal quantities of ultraviolet (UV) inhibitors such as carbon black or titanium dioxide, in geographic areas receiving normal UV exposure. Delays in installation longer than 6 months, from time of manufacturer to time of installation, may be allowed when the Contractor can show that the pipe has been covered or stored indoors for the duration of the additional delay. Inspect materials delivered to site for damage; unload, and store with minimum handling. Do not store materials directly on the ground. The inside of pipes and fittings shall be free of dirt and debris. Keep, during shipment and storage, filter fabric wrapped in burlap or similar heavy duty protective covering. The storage area shall protect the fabric from mud, soil, dust, and debris. Filter fabric materials that are not to be installed immediately shall not be stored in direct sunlight. Install plastic pipe within 6 months from the date of manufacture unless otherwise approved. 1.4.2 Handling Handle materials in such a manner as to ensure delivery to the trench in sound undamaged condition. Pipe shall be carried and not dragged to the trench. PART 2 PRODUCTS 2.1 _{PIPE FOR SUBDRAINS} NOTE: The type or types of pipe to be used will be indicated on the drawings. Where a Contractor's option is to be permitted, the types that are acceptable will be included in the specification. Designers' instructions, including required strength of pipe, are in UFC 3-230-16FA and UFC 3-230-17FA. In specifying pipe for subdrains, pipe of comparable strength for the various sizes and kinds of pipe will be specified. Perforation and slot sizing is based on embedment gradation, flow requirements, and structural considerations. The embedment material gradation is in turn based on the gradation of the surrounding soil. In order to minimize the migration of fines into the coarser material while maintaining adequate permeability, the following criteria should be met: All soils (except clays without a sand or silt fraction): (15 percent size of drainage or filter material)/(85 percent size of material to be drained) = 5 (max) (50 percent size of drainage or filter material)/(50 percent size of material to be drained) = 25 (max) (15 percent size of drainage or filter material)/(85 percent size of material to be drained) = 5 (max) (15 percent size of drainage or filter material = 0.4 (max) All Soils (15 percent size of drainage or filter material)/(15 percent size of material to be drained) = 5 (min) (50 percent size of drainage or filter material)/(slot width) = 1.2 (min) (50 percent size of drainage or filter material)/(hole diameter) = 1.0 (min) Pipe for subdrains shall be of the types and sizes indicated. 2.1.1 Concrete NOTE: Type II cement normally will be specified, but Type V cement will be specified when the soils contain more than 0.2 percent water-soluable sulfate as SO4 or the water contains more than 1,000 parts per million sulfates. Type I cement may be permitted when the water-soluable sulfates in the soil are less than 0.1 percent and the sulfates in the water are less than 150 parts per million. Class 1, 2, or 3 as indicated and conform to ASTM C 14MASTM C 14 using ASTM C 150 portland cement Type [II][V]. 2.1.2 Clay and Perforated Clay 2.1.2.1 Clay Clay pipe shall be either standard or extra strength as indicated and shall conform to ASTM C 700. 2.1.2.2 Perforated Clay Perforated clay pipe shall be either standard or extra strength as indicated and shall conform to ASTM C 700. Plain-end pipe conforming to the strength and perforation requirements of ASTM C 700 will also be acceptable if provided with spring wire clips of approved type to maintain a taut but elastic joint between the sections of pipe when laid. Clips shall be constructed of not smaller than No. 9 hard-drawn or oil-tempered steel wire conforming to ASTM A 227/A 227M or ASTM A 229/A 229M, and shall be coated with an approved rust preventive coating. Wire clips shall withstand 25 cycles of alternate loading and unloading using a stressing force of 556 N 125 pounds. The permanent set resulting from this test shall be less than 5 percent, based on the original length of the fastener. Compression joints conforming to ASTM C 425 will also be acceptable. 2.1.3 Perforated Concrete Conform to ASTM C 444M ASTM C 444, Type [I][II] perforations and to ASTM C 14MASTM C 14, Class 1, 2, or 3 as indicated. 2.1.4 Perforated Corrugated Steel NOTE: Corrugated steel pipe may be installed in soils with a pH range of 6.0 to 8.0 provided the resistivity is greater than 2,000 ohm-cm. A bituminous coating should be used when soil or ground-water conditions are at or near these limits. Perforated corrugated steel pipe shall conform to ASTM A 760/A 760M, Type III. Sheet thickness of pipe shall be as indicated. 2.1.5 Perforated Corrugated Steel, Fully Bitumin. Coated Perforated corrugated steel pipe, fully bituminous coated, shall conform to ASTM A 760/A 760M, Type III, with a coating conforming to AASHTO M 190, Type A. Sheet thickness of pipe shall be as indicated. 2.1.6 Drain Tile NOTE: Drain tile will not be used for general airfield or heliport construction, drainage systems for structures, or for drains crossing adjacent to paved areas, and will be used only for subsoil drainage for drill areas, parade grounds, athletic fields, and other areas similarly used that are subject to lightweight vehicle traffic only, and where conditions justify its use. Special quality of drain tile will be specified for tile laid in soils that are markedly acid or that contain unusual quantities of sulfates. Clay drain tile shall conform to ASTM C 4 standard, extra quality or heavy duty as indicated. Concrete drain tile shall conform to ASTM C 412M ASTM C 412 standard, extra, heavy duty extra, or special quality as indicated. 2.1.7 Porous Concrete NOTE: Type II cement normally will be specified, but Type V cement will be specified when the soils contain more than 0.2 percent water-soluable sulfate as SO4 or the water contains more than 1,000 parts per million sulfates. Type I cement may be permitted when the water-soluable sulfates in the soil are less than 0.1 percent and the sulfates in the water are less than 150 parts per million. Conform to ASTM C 654M ASTM C 654, standard or extra strength as indicated and using ASTM C 150 portland cement Type [II][V]. 2.1.8 Perforated Corrugated Aluminum Alloy NOTE: Corrugated aluminum pipe without bituminous coating may be installed in soil with pH range of 5.5 to 8.5 if the resistivity is greater than 500 ohm-cm or 5.0 to 9.0 where the resistivity is greater than 1,500 ohm-cm. This type of pipe should not be installed in material classified as OH or OL according to the Unified Soil Classification System as presented in ASTM D 2487. Bare aluminum alloy pipe has satisfactory corrosion resistance in clean granular materials even when subjected to sea water. Perforated corrugated aluminum alloy pipe shall conform to ASTM B 745/B 745M, Type III, Class [1] [2]. Sheet thickness of pipe shall be as indicated. 2.1.9 Perforated Corrugated Aluminum Alloy, Fully Bitumin. Coated NOTE: Corrugated aluminum pipe, fully bituminous coated, may be considered in soils where the pH range is 6.0 to 8.0 and resistivity is greater than 2,000 ohm-cm. Perforated corrugated aluminum alloy pipe, fully bituminous coated shall conform to ASTM B 745/B 745M, Type III, Class [1] [2] with a bituminous coating conforming to AASHTO M 190, Type A. 2.1.10 Precoated Corrugated Steel Precoated corrugated steel pipe shall conform to ASTM A 762/A 762M, Type III. 2.1.11 Plastic Plastic pipe shall contain ultraviolet inhibitor to provide protection from exposure to direct sunlight. 2.1.11.1 Acrylonitrile-Butadiene-Styrene (ABS) Acrylonitrile-butadiene-styrene (ABS) piping and fittings shall conform to ASTM D 2751, with maximum SDR of 35. 2.1.11.2 Polyvinyl Chloride (PVC) and Fittings Polyvinyl chloride (PVC) pipe and fittings shall conform to [ASTM D 3034,] [ASTM F 949,] [ASTM F 758, Type PS 46]. 2.1.11.3 Corrugated Polyethylene (PE) and Fittings Use [ASTM F 405 for pipes 80 to 150 mm 3 to 6 inches in diameter, inclusive, ASTM F 667 for pipes 200 to 600 mm 8 to 24 inches in diameter] [AASHTO M 252 for pipes 80 to 250 mm 3 to 10 inches, AASHTO M 294 for pipes 300 to 600 mm 12 to 24 inches in diameter]. Fittings shall be manufacturer's standard type and shall conform to the indicated specification. 2.1.11.4 Pipe Perforations Water inlet area shall be a minimum of 1,058.4 mm squared per linear meter 0.5 square inch per linear foot. Manufacturer's standard perforated pipe which essentially meets these requirements may be substituted with prior approval of the Contracting Officer. a. Circular Perforations in Plastic Pipe: Circular holes shall be cleanly cut not more than 9.5 mm 3/8 inch or less than 4.8 mm 3/16 inch in diameter and arranged in rows parallel to the longitudinal axis of the pipe. Perforations shall be approximately 76.2 mm 3 inches center-to-center along rows. The rows shall be approximately 38.1 mm 1-1/2 inches apart and arranged in a staggered pattern so that all perforations lie at the midpoint between perforations in adjacent rows. The rows shall be spaced over not more than 155 degrees of circumference. The spigot or tongue end of the pipe shall not be perforated for a length equal to the depth of the socket, and perforations shall continue at uniform spacing over the entire length of the pipe. b. Slotted Perforations in Plastic Pipe: Circumferential slots shall be cleanly cut so as not to restrict the inflow of water and uniformly spaced along the length and circumference of the tubing. Width of slots shall not exceed 3.2 mm 1/8 inch nor be less than 0.8 mm 1/32 inch. The length of individual slots shall not exceed 31.75 mm 1-1/4 inches on 80 mm 3 inch diameter tubing, 10 percent of the tubing inside nominal circumference on 100 to 200 mm 4 to 8 inch diameter tubing, and 63.5 mm 2-1/2 inches on 250 mm 10 inch diameter tubing. Rows of slots shall be symmetrically spaced so that they are fully contained in 2 quadrants of the pipe. Slots shall be centered in the valleys of the corrugations of profile wall pipe. 2.2 _{FILTER FABRIC} NOTE: When filter fabric is not used in the drainage system, the requirement for filter fabric will be deleted from this specification. Design criteria for filter fabrics are based on the equivalent opening size (AOS), percent open area (POA), and filter fabric permeability (Kg). The EOS is defined as the number of the US Standard Sieve having openings closest in size to the largest openings in the filter fabric. The AOS specified should be based on the criteria described below. To perform piping criteria computations, the AOS must be expressed as the equivalent US standard sieve opening in millimeters. The AOS can be used for woven and nonwoven fabrics. Where a designer desires to use "percent open area," the percent open area should be based on the criteria below. The percent open area should be used only for woven fabrics. The permeability test can be used for nonwoven and woven fabrics. The AOS test is a means of evaluating the piping resistance of a filter fabric, and the percent open area test is intended to assure adequate flow through the fabric and adequate resistance to reduction in permeability over time (clogging). The percent open area test is an indirect test which has been shown to correlate with a woven fabric's long term permeability. The permeability test measures the ability of the filter fabric to pass water without any soil on the fabric. This test does not provide a direct measure of field performance of the filter fabric. The designer must specify filter fabric properties which will allow retention of the soil being protected, permit sufficient flow through the fabric, and prevent clogging. The designer should select the AOS, POA, and Kg, based on the following criteria:    Protected Soil       Percent Passing            Piping  (a.)        Woven         Nonwoven       0.075 mm (No. 200) Sieve   Maximum AOS (mm)         Minimum POA      ________________________    _________________        _____________       Less than 5                 D85 (c.)          10 percent         Ks (d.)       percent   (b.)       5 percent to 50             D85                4 percent         Ks       percent   (b.)       50 percent to          (a.) D85                4 percent         Ks       85 percent             (b.) Upper Limit                              on AOS is AOS                              = 0.212 mm                              (No. 70) US                              Standard Sieve       More than              (a.) = D85                                Ks       85 percent             (b.) Lower Limit                              on AOS is AOS                              = 0.125 mm                              (No. 120) US                              Standard Sieve a. When the protected soil contains appreciable quantities (20 to 30 percent) of material retained on the 4.75 mm, (No. 4) sieve, use only the soil passing the 4.75 mm (No. 4) sieve in selecting the AOS of the filter fabric. b. These protected soils may have a large permeability and thus the POA of Kg may be a critical design factor. c. D85 is the grain size in millimeters for which 85 percent of the sample by weight has smaller grains. d. Kg is the permeability of the nonwoven fabric, and Ks is the permeability of the protected soil. The AOS requirement should be specified as a range to allow for manufacturing tolerances. The smallest sieve opening size of the AOS range should not be smaller than the openings of a 0.125 mm (No. 120) US Standard Sieve. It is preferable to specify a filter fabric with openings as large as allowed by the criteria. Fabric strength requirements vary with intended use and construction procedures. Experience has shown that when a heavier nonwoven fabric is used, the bedding material can often be reduced in thickness or completely eliminated. Recommended values are: Type               Minimum                 Test         ______             _________               _______          Tensile      444.8 N (100 lbs)  ASTM D 5034 grab test 25.4 mm                                           (1 inch) square and 304.8 mm                                           (12 inches) per minute constant                                           rate at traverse.          Elongation         15 percent    ASTM D 5034 determine apparent                                           breaking elongation.          Puncture     177.8 N (40 lbs.)  ASTM D 3787 except polished steel                                          ball replaced with a 8 mm (5/16                                          inch) diameter solid steel                                          cylinder with a hemispherical tip                                          centered within the ring clamp.          Tear         111.2 N (25 lbs.)  ASTM D 1117 trapezoidal tear                                          strength. Filter fabrics used to wrap collector pipes should be surrounded by at least 150 mm (6 inches) of granular material. If the filter fabric is used to line a trench, the collector pipe should be separated from the fabric by a minimum of 150 mm (6 inches) of granular backfill material. Filter fabric shall be a pervious sheet of polyester, nylon, or polypropylene filaments woven or otherwise formed into a uniform pattern with distinct and measurable openings. The filter fabric shall provide an equivalent opening size (AOS) no finer than the US Standard Sieve No. [_____] and no coarser than the US Standard Sieve No. [_____]. AOS is defined as the number of the US Standard sieve having openings closest in size to the filter fabric openings. [The percent open area provided shall not be less than [_____] percent and not more than [_____] percent. Percent open area is defined as the summation of open areas divided by the total area of the filter fabric and expressed as a percent.] [The filaments shall consist of a long-chain synthetic polymer composed of at least 85 percent by weight of propylene, ethylene, or vinylidene-chloride, and shall contain stabilizers and/or inhibitors added to the base plastic to make the filaments resistant to deterioration due to ultraviolet and heat exposure.] The fabric shall have a minimum physical strength of [_____] N/meter pounds per inch in any direction when tested in accordance with ASTM D 5034 using the grab test method with 645.2 square mm 1 square inch jaws and a constant rate of travel of 304.8 mm 12 inches per minute. Elongation at failure shall be between [30] [_____] and [70] [_____] percent. The fabric shall be constructed so that the filaments will retain their relative position with respect to each other. [The edges of the fabric shall be selvaged or otherwise finished to prevent the outer material from pulling away from the fabric.] [The fabric shall be woven into a width that may be installed as shown without longitudinal seams.] 2.3 SUBDRAIN FILTER AND BEDDING MATERIAL NOTE: The thickness and gradation of the filter material for use with pipe subdrains and blind or french drains will be determined by soil conditions and subsoil drainage requirements. Filter material will be graded in accordance with the requirements of UFC 3-230-06A, as applicable. TABLE I includes the requirements for each specific installation. The filter material placed adjacent to perforated pipe and open joints will be of a size that will prevent the entrance of any of the filter material into the drain. Graded (composite or layered) filters will be used where specified, and cross sections will be as indicated on the drawings. For pipe with perforations, the filter material will extend from a point not less than 150 mm (6 inches) below the pipe to a point up the sides of the pipe not less than 50.8 mm (2 inches) above the horizontal centerline. For bell-and-spigot or tongue-and-groove pipe laid as specified in paragraph EXCAVATION AND BEDDING FOR SUBDRAIN SYSTEMS, additional filter material not less than 150 mm (6 inches) thick and 300 mm (12 inches) wide will be placed entirely around the joints. Sieve sizes and gradation requirement are inserted in TABLE I using the applicable values from TABLE II. Where site conditions require more than one filter gradation, the drawings will indicate areas of different gradation and the table expanded. Subdrain filter and bedding material shall be washed sand, sand and gravel, crushed stone, crushed stone screenings, or slag composed of hard, tough, durable particles free from adherent coatings. Filter material shall not contain corrosive agents, organic matter, or soft, friable, thin, or elongated particles and shall be evenly graded between the limits specified in TABLE I. TABLE II shows values that can be used to complete TABLE I. Gradation curves will exhibit no abrupt changes in slope denoting skip or gap grading. Filter materials shall be clean and free from soil and foreign materials. Filter blankets found to be dirty or otherwise contaminated shall be removed and replaced with material meeting the specific requirements, at no additional cost to the Government. TABLE I.  FILTER GRADATION              Sieve                  Percent by Weight Passing                                    ___________________________           Designation        Gradation A   Gradation B   Gradation C          _____________      _____________ _____________ _____________ TABLE II                    [Type I            Type II          Type III                  [Gradation E 11    [Gradation 57      [Gradation [_____]                  ASTM C 33]         ASTM C 33]           [_____]]]   [[ASTM D 422   Sieve Size]    [Percent Passing]  [Percent Passing]  [Percent Passing]       37.5 mm            --                100              [_____]       25.0 mm            --              90 - 100           [_____]       9.5 mm            100              25 - 60            [_____]       4.75 mm         95 - 100            5 - 40            [_____]       2.36 mm            --               0 - 20            [_____]       1.18 mm         45 - 80               --              [_____]   300 micrometers     10 - 30               --              [_____]   150 micrometers      0 - 10               --              [_____]] TABLE II                   [Type I            Type II              Type III                   [Gradation E 11    [Gradation 57        [Gradation [_____]]                   ASTM C 33]         ASTM C 33]             [_____]]   [[ASTM D 422   Sieve Size]    [Percent Passing]   [Percent Passing]    [Percent Passing]   1.5 inches          --                   100                [_____]   1 inch              --                 90 - 100             [_____]   3/8 inch            100                25 - 60              [_____]   No. 4             95 - 100              5 - 40              [_____]   No. 8               --                  0 - 20              [_____]   No. 16            45 - 80                --                 [_____]   No. 50            10 - 30                --                 [_____]   No. 100            0 - 10                --                 [_____]] 2.4 DRAINAGE STRUCTURES 2.4.1 Concrete NOTE: Delete the last sentence when exposed-to-view concrete surfaces will not be subjected to the action of deicing chemicals. The required air contents are for concrete that will be subjected to freezing weather and the possible action of deicing chemicals. In climates where freezing is not a factor, but where air entrainment is used in local commercial practice to improve the workability and placability of concrete, concrete having air content of 3 to 6 percent may be specified. Except for precast concrete, reinforcement shall conform to the requirements for [21] [_____] MPa [3,000] [_____] psi concrete in Section 03 31 00.00 10 CAST-IN-PLACE STRUCTURAL CONCRETE. The concrete mixtures shall have air content, by volume of concrete, based on measurements made immediately after discharge from the mixer of [5 to 7] [3 to 6] percent when coarse-aggregate maximum size is 38.1 mm 1-1/2 inches or smaller. Air content shall be determined in accordance with ASTM C 231. The concrete covering over steel reinforcing shall be not less than 25.4 mm 1 inch thick for covers and not less than 38.1 mm 1-1/2 inches thick for walls and flooring. Concrete covering deposited directly against the ground shall be at least 76.2 mm 3 inches thick between the steel and the ground. Expansion-joint filler material shall conform to ASTM D 1751 or ASTM D 1752. Exposed concrete surfaces, such as drainage structures that form a continuation of concrete curbs and gutters, shall be given a protective coating of linseed oil as specified in Section 32 16 13 CONCRETE SIDEWALKS AND CURBS AND GUTTERS. 2.4.2 Mortar Mortar for pipe joints and connections to other drainage structures shall be composed of one part by volume of portland cement and two parts of sand. The quantity of water in the mixture shall be sufficient to produce a stiff workable mortar. Water shall be clean and free of injurious acids, alkalies, and organic impurities. The mortar shall be used within 30 minutes from the time the ingredients are mixed with water. 2.4.3 Manholes and Appurtenances 2.4.3.1 Precast Reinforced Concrete Manhole Risers and Tops Conform to ASTM C 478M ASTM C 478. 2.4.3.2 Precast Concrete Segmental Blocks Precast concrete segmental blocks shall conform to ASTM C 139 and shall be not more than 203.2 mm 8 inches thick, not less than 203.2 mm 8 inches long, and of such shape that the joints can be effectively sealed and bonded with cement mortar. 2.4.3.3 Precast Concrete Manhole Bases If precast concrete manhole bases are used, the bases shall conform to ASTM C 478MASTM C 478 and shall be of such a design as to effect suitable connection with influent and effluent lines and to provide a suitable base structure for riser sections. 2.4.3.4 Brick Brick shall conform to ASTM C 62, Grade SW, or ASTM C 55, Grade S-I or S-II. Mortar for jointing and plastering shall consist of one part portland cement and two parts fine sand. Lime may be added to the mortar in the amount of not more than 25 percent by volume of cement. 2.4.3.5 Prefabricated Corrugated Metal Steel manholes and risers shall be fabricated of at least [_____] gauge galvanized [and bituminous coated] corrugated metal. 2.4.3.6 Glass Fiber-Reinforced Polyester (FRP) FRP manholes shall conform to ASTM D 3753. 2.4.3.7 Frames and Covers or Gratings Frames and gratings, or frames and covers, except as otherwise permitted, shall be of either cast iron with tensile strength test not less than ASTM A 48/A 48M Class 25 or steel conforming to ASTM A 27/A 27M, Class 65-35. Weight, shape, and size shall be as indicated. Frames and covers not subjected to vehicular traffic or storage may be of malleable iron where indicated. The malleable-iron frames and covers shall conform to ASTM A 47/A 47M and shall be of the weight, shape, and size indicated. 2.4.3.8 Steel Ladder A steel ladder shall be provided where the depth of a manhole exceeds 3.66 m 12 feet. The ladder will be not less than 400 mm 16 inches in width, with 19.1 mm 3/4 inch diameter rungs spaced 304.8 mm 12 inches apart. The two stringers shall be a minimum 9.5 mm 3/8 inch thick and 50.8 mm 2 inches wide. Ladder shall be adequately anchored to the wall by means of steel inserts spaced not more than 1.83 m 6 feet apart vertically, and shall be so installed as to provide at least 152.4 mm 6 inches of space between the wall and the rungs. Ladders and inserts shall be galvanized after fabrication in conformance with ASTM A 123/A 123M. The wall along the line of the ladder shall be vertical for its entire length. PART 3 EXECUTION 3.1 EXCAVATION AND BEDDING FOR SUBDRAIN SYSTEMS Trenching and excavation, including the removal of rock and unstable material, shall be in accordance with Section 31 00 00 EARTHWORK. Bedding material shall be placed in the trench as indicated or as required as replacement materials used in those areas where unstable materials were removed. Compaction of the bedding material shall be as specified for cohesionless material in Section 31 00 00 EARTHWORK. 3.2 MANHOLES AND FLUSHING AND OBSERVATION RISERS NOTE: The details indicating size, shape, materials, thickness of various sections, the finish required, and amounts or reinforcing, if any, for inlets, catch basins, walls, headwalls, and manholes will be shown in the drawings. Also, the shape, size, thickness of sections, kind of materials, and weight for frames, covers, and gratings for inlets, catch basins, and manholes, as well as the amount of waterway opening for inlet and catch basins will be indicated in the drawings. The covers and gratings will be designed to have ample strength for the traffic conditions to which they may be subjected. Fixed ladders or ladder rungs will be provided for manholes 3.66 m (12 feet) or deeper measured from top of grate to invert of outlet pipe. 3.2.1 Manholes Manholes shall be installed complete with frames and covers or gratings at the locations and within the limits and sizes indicated. Manholes shall be constructed of one of the materials specified for manholes in paragraph DRAINAGE STRUCTURES. Joints shall be completely filled and shall be smooth and free of surplus mortar or mastic on the inside of the structure. Brick manholes shall be plastered with 12.7 mm 1/2 inch of mortar over the entire outside surface of the walls. Brick for square or rectangular structures shall be laid in stretcher courses with a header course every sixth course. Brick for round structures shall be laid radially with every sixth course laid as a stretcher course. Ladders shall be installed in manholes as indicated. Base for manholes shall be either precast or cast-in-place concrete. 3.2.2 Flushing and Observation Risers Flushing and observation riser pipes with frames and covers shall be installed at the locations indicated. Risers shall be constructed of precast concrete, vitrified clay, or [galvanized] [bituminous coated] corrugated metal pipe. Joining of riser pipes to the subdrain system shall be as indicated. 3.3 INSTALLATION OF FILTER FABRIC AND PIPE FOR SUBDRAINS NOTE: Outlets for subsoil drains and for blind drains, if possible, within reasonable costs, will be designed so that severe rainstorms will neither submerge the drains nor back up water into the drains. Where outlets are not subject to backwater or flooding, the outlets will be provided with grates or heavy screens to prevent acts of vandalism or entrance by rodents. If suitable outlets for blind or french drains into pervious strata of gravel or sand with a lower water table are not obtainable, pipe outlets may be required. The open joint or perforated pipe will extend into the filter material of the blind or french drain a sufficient distance to provide ample waterway openings for the particular drain and will extend through the impervious material, usually with closed joints, to a suitable outlet. Outlets subject to flooding will be provided with suitable and properly installed check valves or flap gates. If outlet pipes are necessary for blind or french drains, and are to be paid for as a separate item, such requirement will be clearly specified, giving the various kinds and sizes of pipe required. 3.3.1 Installation of Filter Fabric NOTE: When filter fabric is not used in the drainage system, the requirement for filter fabric will be deleted from this specification. 3.3.1.1 Overlaps on Perforated or Slotted Pipes NOTE: When the permeability of the backfill material is sufficient so that only a single-stage filter is required between the backfill and perforated pipe, filter fabric may be used for this single-stage filter. In this case the filter fabric should wrap the collector pipes, and permanent devices to secure the fabric to the pipe are not needed since the fabric will be held in place by the backfill material once the installation is completed. Filter fabric has been satisfactorily secured to pipes with tape or string placed at about 300 mm (1 foot) intervals along the overlap. The free ends of the cloth have been folded and stapled. Prefabricated filter fabric sheaths have also been used successfully. The seams for such sheaths need not be sewn with a permanent type of thread. When a two-stage filter is required, filter fabric may be used in place of the finer filter material. One layer of filter fabric shall be wrapped around perforated or slotted collector pipes in such a manner that longitudinal overlaps of fabric are in unperforated or unslotted quadrants of the pipes. The overlap shall be at least 50 mm 2 inches. The fabric shall be secured to the pipe in such a manner that backfill material will not infiltrate through any fabric overlaps. 3.3.1.2 Installation on Open-Joint Pipe One layer of filter fabric shall be wrapped around open joints. The overlap should be at least 50 mm 2 inches . The fabric shall be secured to the pipe in such a manner that backfill material will not infiltrate through the overlap or the edges of the fabric to either side of the open joint. 3.3.1.3 Trench Lining and Overlaps NOTE: Overlaps of fabric used to line drainage trenches should be from 150 to 300 mm (6 to 12 inches). The strength properties of most filter fabrics composed of plastic materials are adversely affected by ultraviolet rays. Consequently, the fabric should be exposed to sunlight as little as possible, and preferably should be covered the same day as installed. When filter fabric is used to separate the filter material from the soil being drained, the gradation ratios of filter material to protected soil given in UFC 3-230-06A, do not apply; however, the filter fabric must be sized to filter the protected soil. Trenches to be lined with filter fabric shall be graded to obtain smooth side and bottom surfaces so that the fabric will not bridge cavities in the soil or be damaged by projecting rock. The fabric shall be laid flat but not stretched on the soil, and it shall be secured with anchor pins. Overlaps shall be at least [_____] mm inches, and anchor pins shall be used along the overlaps. 3.3.2 Installation of Pipe for Subdrains 3.3.2.1 Pipelaying Each pipe shall be carefully inspected before it is laid. Any defective or damaged pipe shall be rejected. No pipe shall be laid when the trench conditions or weather is unsuitable for such work. Water shall be removed from trenches by sump pumping or other approved methods. The pipe shall be laid to the grades and alignment as indicated. The pipe shall be bedded to the established gradeline. Perforations shall be centered on the bottom of the pipe. Pipes of either the bell-and-spigot type or the tongue-and-groove type shall be laid with the bell or groove ends upstream. All pipes in place shall be approved before backfilling. 3.3.2.2 Jointings a. Nonperforated Concrete and Clay Pipe: Pipe shall be laid with 3.2 to 6.4 mm 1/8 to 1/4 inch opening between the ends of the pipe or as required by spacing lugs constructed in the pipe. Mortar shall be placed in the joint at three points and pressed firmly into place to hold the pipe securely in line. The mortar shall be the full depth of the bell or groove and approximately 25.4 1 inch in width, and shall be located at the third points around the joint with the top point at the center of the pipe. The inside of the pipe shall be free of excess mortar. b. Perforated Concrete and Clay Pipe: The pipe shall be laid with closed joints with positive provision for centering each section of the pipe in the bell or groove of the previously placed section. Plain-end perforated clay pipe sections shall be securely fastened together with spring wire clips furnished by the pipe manufacturer. c. Perforated Corrugated Metal Pipe or Bituminous Coated, Perforated Corrugated Metal Pipe: The sections of perforated corrugated metal pipe or bituminous coated, perforated corrugated metal pipe shall be securely fastened together with standard connecting bands furnished by the manufacturer of the pipe. d. Drain Tile: Drain tile shall be bedded as provided for bell-and-spigot or tongue-and-groove types of pipe and laid with open joints of approximately 3.2 mm 1/8 inch width but not over 6.4 mm 1/4 inch width. Drain tile shall be protected against the entrance of filter material into the line by the use of filter fabric. e. Porous Concrete Pipe: Porous concrete pipe shall be installed with mortar joints. f. Perforated Asbestos-Cement Pipe: Couplings shall be of the sleeve type suitable for holding the pipe firmly in alignment without the use of sealing compounds or gaskets. Tapered couplings will be acceptable. g. Bituminous Coated or Uncoated Semicircular Steel Pipe: Coupling bands shall consist of an uncorrugated top and bottom section fabricated to fit around two adjacent pieces of pipe. Coupling bands shall be bolted together with four bolts. h. Bituminous Coated or Uncoated Corrugated Aluminum Pipe: If aluminum pipe is to be connected to dissimilar metal, the connection shall be insulated by bituminous coating or other nonconductive material. Standard joints between corrugated aluminum pipe shall be securely fastened with standard connecting bands furnished by the manufacturer of the pipe. i. Acrylonitrile-Butadiene-Styrene (ABS): Solvent cement or elastomeric joints for ABS pipe shall be in accordance with ASTM D 2751. Dimensions and tolerances shall be in accordance with TABLE II of ASTM D 2751 . j. Polyvinyl Chloride (PVC) Pipe: Joints shall be in accordance with the requirements of ASTM D 3034 , ASTM D 3212, or ASTM F 949. k. Perforated Corrugated Polyethylene Pipe: Perforated corrugated polyethylene drainage pipe shall be installed in accordance with the manufacturer's specifications and as specified herein. A pipe with physical imperfections shall not be installed. No more than 5 percent stretch in a section will be permitted. 3.4 INSTALLATION OF AND BACKFILLING FOR BLIND OR FRENCH DRAINS NOTE: Outlets for subsoil drains and for blind drains, if possible, within reasonable costs, will be designed so that severe rainstorms will neither submerge the drains nor back up water into the drains. Where outlets are not subject to backwater or flooding, the outlets will be provided with grates or heavy screens to prevent acts of vandalism or entrance by rodents. If suitable outlets for blind or french drains into pervious strata of gravel or sand with a lower water table are not obtainable, pipe outlets may be required. The open joint or perforated pipe will extend into the filter material of the blind or french drain a sufficient distance to provide ample waterway openings for the particular drain and will extend through the impervious material, usually with closed joints, to a suitable outlet. Outlets subject to flooding will be provided with suitable and properly installed check valves or flap gates. If outlet pipes are necessary for blind or french drains, and are to be paid for as a separate item, such requirement will be clearly specified, giving the various kinds and sizes of pipe required. Filter material shall be placed as indicated and compacted as specified for cohesionless materials in Section 31 00 00 EARTHWORK. Filter material shall extend to a suitable outlet or to an outlet through a pipeline as indicated. Overlying backfill material shall be placed and compacted as specified in Section 31 00 00 EARTHWORK. 3.5 INSTALLATION OF FILTER MATERIAL AND BACKFILLING FOR SUBDRAINS After pipe for subdrains has been laid, inspected, and approved, filter material shall be placed around and over the pipe to the depth indicated. The filter material shall be placed in layers not to exceed 200 mm 8 inches thick, and each layer shall be [saturated by flooding] [thoroughly compacted by mechanical tampers or rammers] to obtain the required density. Compaction of filter material and the placement and compaction of overlying backfill material shall be in accordance with the applicable provisions specified in Section 31 00 00 EARTHWORK. 3.6 TESTS 3.6.1 Pipe Test Strength tests of pipe shall conform to field service test requirements of the Federal Specification, ASTM specification, or AASHTO specification covering the product (paragraph PIPE FOR SUBDRAINS). 3.6.2 JP-4 Fuel Resistance Test NOTE: Delete this paragraph when filter fabric will not be exposed to JP-4 fuel. Five unaged fabric samples, 97 to 107 mm by 147 to 157 mm 4 (plus or minus 0.2) by 6 (plus or minus 0.2) inches shall be immersed in JP-4 fuel at room temperature for a period of 7 days. Each sample then shall be tested for tensile strength and elongation in accordance with ASTM D 5034. The strength of the fabric in any direction shall be no less than 85 percent of the strength specified in paragraph FILTER FABRIC.