603.01 603-1 SECTION 603 CULVERT S AND SEWERS DESCRIPTION
603.01 This work consists of the construction of culverts (cross drains), side drains, storm
drains, and sanitary sewers referred to as “conduit ”, where a specific pipe material is required, and nestable semicircular pipe for encasement. Work shall be per these specifications and in conformity with the lines and grades shown on the plans or established. MATERIALS
603.02 Materials shall meet the requirements shown on the plans and in the following
subsections: Corrugated Steel Pipe and Pipe Arches 707.02 Corrugated Steel Pipe Nestable 707.02 Corrugated Aluminum Pipe 707.06 Reinforced Concrete Pipe 706.02 Nonreinforced Concrete Pipe 706.01 Pipe Joint Sealing Compounds 705.04 Plastic Pipe 712.13 Vitrified Clay Pipe 706.06 Ductile Iron Pipe 707.01 Gaskets 705.03 Resilient Compression Ring Material 705.05 Reinforced Concrete Pipe (Jacked) 706.02 Plastic end sections shall not be used. When plastic pipe is to be installed with end sections, steel end sections conforming to Standard Plans M -603-10 and M -603-12 shall be used. CONSTRUCTION REQUIREMENTS
603.03 General. Pipe shall be protected during handling against impact shocks and free fall.
When new sanitary sewer facilities interfere with the existing flow of sewage, the Contractor shall provide satisfactory bypass facilities at no expense to the Department. Sanitary sewers and all appurtenances shall be thoroughly cleaned before final acceptance of this work.
603.04 Excavation . Trenches shall be excavated per the requirements of Section 206 to a
width sufficient to allow for proper jointing of the conduit and thorough compaction of the bedding and backfill material under and around the conduit. The completed trench bottom shall be firm for its full length and width. The trench for cross drains shall have a minimum longitudinal camber of 1 percent of the length of the pipe. Camber may be increased to suit the height of fill and supporting soil. 603.05 603-2 When conduits are to be installed in new embankments, the embankment shall first be constructed to the required height of at least 0.3 times the outside diameter or raise of the conduit, and for a distance each side of the conduit location of at least 5 times the diameter or span of the conduit, after which , the trench shall be excavated, and the conduit installed. Excavation shall be by open cut from the surface, except when pipe jacking is specified or directed in writing by the Engineer. When pipe is to be jacked, trenching will not be permitted. Pipe must be jacked without disrupting traffic. Methods of installing pipe other than by jacking may be used only with written approval from the Engineer. Methods that may cause damage to the embankment or roadway area will not be approved. Damage to the pipe or installation area caused by jacking operations shall be repaired or replaced at the Contractor's expense. The area around the outer surface of the pipe shall be thoroughly grouted. The grout mixture shall consist of one part portland cement and three parts of fine aggregate by volume, or it may be determined by prior documented experience with similar materials, equipment, and field conditions. The grout shall be thoroughly mixed with the minimum quantity of water nee ded to obtain the proper consistency for the existing soil conditions.
603.05 Bedding for Concrete or Clay Conduit . Bedding shall be prepared per details as
shown on the plans. The bed shall consist of a layer of loose structure backfill at least 3 inches in thickness. Recesses shall be made to accommodate the bell of bell -and-spigot pipe . Adjustments to line and grade shall be made by scraping or filling under the body of the conduit. Wedging or blocking the bell will not be permitted.
603.06 Placing Conduit . The conduit laying shall begin at the downstream end of the
conduit line. The lower segment of the conduit shall be in contact with the prepared bedding throughout its full length. Bell or groove ends of concrete or clay conduits and outside circumferentia l laps of metal or plastic conduits shall be placed facing upstream. Paved or partially lined conduit shall be placed so that the longitudinal centerline of the paved segment coincides with the flow line. Elliptical- shaped pipe and circular pipe with elliptical reinforcement shall have the top clearly marked with paint or with imprinted letters and with lifting eyeholes where laying pins can be used. Holes shall be finished smooth with grout or with plugs. Conduits shall be placed with the vertical axis within five degrees of a vertical plane through the longitudinal axis of the conduit.
603.07 Joining Conduit . Joint systems for siphons, irrigation systems, and storm drains shall
be watertight.
a.Concrete or Clay Conduit . Conduit sections shall be joined in such a manner that the ends are fully entered, and the inner surfaces are reasonably flush and even. At locations where rubber gaskets are specified in the Contract for conduits used for storm drains and cross culverts, rubber gaskets conforming to subsection 705.03 shall be used. At locations where the type of joint is not otherwise specified in the Contract for conduit used for storm drains and cross culverts, joints shall be m ade with joint sealing compound. Primer shall be furnished when recommended by the manufacturer of the joint sealing compound. Primer shall conform to and shall be applied per the manufacturer's recommendations to both surfaces of the conduit sections being joined, for the full circumference. Sealing compound shall be applied according to the manufacturer's recommendations. When a specific type of sealing compound is desired, it shall be as shown in the Contract. 603.08 603-3 Rubber gaskets conforming to subsection 705.03 shall be used for concrete pipe sanitary sewer joints. Resilient pressure ring material conforming to subsection 705.05 shall be used for clay pipe sewer joints.
b.Metal Conduit . Corrugated metal pipe sections shall be placed and aligned to within 3/4 inch of the adjacent section and shall be firmly joined with either one- piece or two -piece coupling bands. Pipe with helical corrugations shall be joined with the corrugations matched across the joints and with all corrugations of the pipe completely engaged by the corrugations or dimples of the coupling band. Where existing corrugated metal pipe culverts are to be extended, damaged ends shall be cut off or repaired in an approved manner. All ends of pipes requiring extensions shall be cleaned within the area necessary for proper installation of connecting bands . Arch culverts shall be extended with pipe having a compatible arch shape. When special joint treatment is called for on the plans to prevent infiltration or exfiltration, the joints shall be made using a sealing compound conforming to subsection 705.04, with the connecting band.
c.Plastic Conduit . Couplings shall be as recommended by the conduit manufacturer. Watertight joint systems for plastic pipe shall conform to subsection 705.02.
603.08 Elongation . Where required by the plans, round metal and plastic conduit shall be
preformed to an elliptical shape by elongating the vertical axis 5 percent.
603.09 Backfilling . After the conduit or section of conduit is placed, it shall be inspected before
any backfill is placed. Reinforced concrete pipe (RCP ) shall be visually inspected per AASHTO LRFD Bridge Construction Specifications, Section 27.6. Conduit found to be damaged shall be replaced, and conduit found to be out of alignment or unduly settled shall be taken up and relaid. The trench shall then be backfilled with material per Section 206. Sanitary sewer lines, when completed, shall be tested for watertightness before any backfill is placed. The installation shall not show infiltration or exfiltration in excess of 0.6 gallon per inch of internal pipe diameter per 100 feet of sewer line per hour when tested at 10 psi by hydraulic means. Testing of joints shall be performed by the Contractor per approved methods. Should any section of the sewer line fail to meet the test requirements, it shall be corrected at the Contractor’s expense. Special care shall be taken when backfilling around conduit to bring the backfill materials up on both sides of the conduit, evenly and simultaneously. Protection of conduits during construction shall be the Contractor's responsibility. Damage to the condu it due to the Contractor’s operations shall be repaired or replaced at the Contractor's expense. Trenches in existing streets, except streets that are to be closed or abandoned, shall be resurfaced as soon as practicable with the type and thickness of bases and pavement shown in the Contract or as designated. After culvert pipe is backfilled and earthwork over the pipe is complete to the top of the subgrade, the pipe deflection shall be measured in the presence of the Engineer . The 603.10 603-4 maximum allowable deflection shall be 5 percent. Deflection is a reduction in the inside diameter of the pipe measured in any direction. Measurement shall be made using a mandrel, laser profile, or other method approved by the Engineer. Measurement shall b e made 30 days or more following the pipe installation. Pipe having any deflections in excess of 5 percent at any location within the pipe shall be removed and reinstalled. Pipe that is permanently deformed or damaged in any way shall be replaced. Replaced pipe shall be retested 30 days or more after the installation per the method described above.
603.10 Deflection Testing of Metal and Plastic Pipe. After a metal or plastic pipe is
backfilled and earthwork over the pipe is complete to the top of the subgrade, the pipe deflection shall be measured in the presence of the Engineer. The maximum allowable deflection shall be 5 percent. Deflection is a reduction in the nominal diameter o f the pipe measured in any direction. Measurement shall be made using a mandrel, laser profile, or other method approved by the Engineer. Measurement shall be made 30 days or more following the pipe installation. Pipe hav ing any deflections in excess of 5 percent at any location within the pipe shall be removed and reinstalled at the Contractor’s expense. Pipe that is permanently deformed or damaged in any way shall be replaced at the Contractor’s expense. Replaced pipe s hall be retested 30 days or more after the installation per the method described above.
603.11 Repair of Damaged Culvert . Coating on corrugated steel pipe and pipe arches, and
corrugated steel pipe nestable shall be repaired per the provisions of subsection 707.09. Damaged pipe shall not be repaired. The Engineer will determine when the pipe is either acceptable or unacceptable per the provisions of subsection 105.03. Unacceptable pipe shall be removed and replaced. METHOD OF MEASUREMENT
603.12 Conduit used for culverts and storm drains of the different types and sizes and
corrugated steel pipe nestable will not be measured but will be the net length of pipe called for on the plans, except when field changes are ordered or when there are errors o n the plans. In case of exceptions, the quantity to be measured shall be the actual net length of the conduit measured along the bottom centerline. Extra length of the conduit due to joint creep will not be measured and paid for. Corrugated steel pipe nestable used for encasement will be measured as complete circular pipe. Jacked pipe will be measured by the linear foot complete in place and accepted. Structure excavation, structure backfill, grout materials, and grouting operation for jacked pipe will not be measured and paid for separately but shall be included in the work. End sections and safety grates will be measured by the number of units installed. The size designation of metal pipe arch and metal pipe arch end section shall refer to the diameter of round pipe normally used to fabricate the pipe arch or the pipe portion of the end section. Relaid pipe will be measured and paid for per Section 210. 603.13 603-5 BASIS OF PAYMENT
603.13 The accepted quantities will be paid for at the contract unit price for each of the pay
items listed below that appear in the bid schedule. Except as otherwise indicated on the plans or in the special provisions, all joints, elbows, concrete collars, connecting bands , and other connecting devices will not be paid for separately but shall be included in the work. Payment will be made under: Pay Item Pay Unit ___Inch Corrugated Steel Pipe Linear Foot ___Inch Corrugated Steel Pipe Nestable Linear Foot ___Inch Steel End Section Each ___Inch Equiv. Corrugated Steel Pipe Arch Linear Foot ___Inch Equiv. Arch Steel End Section Each ___Inch Corrugated Aluminum Pipe Linear Foot ___Inch Aluminum End Section Each ___Inch Equiv. Corrugated Aluminum Pipe Arch Linear Foot ___Inch Equiv. Arch Aluminum End Section Each ___Inch Reinforced Concrete Pipe Linear Foot ___Inch Reinforced Concrete End Section Each ___Inch Nonreinforced Concrete Pipe Linear Foot ___Inch x ___Inch Reinforced Concrete Pipe Elliptical Linear Foot ___Inch x ___Inch Reinforced Concrete End Section Elliptical Each ___Inch Vitrified Clay Pipe Linear Foot ___Inch Cast Iron Pipe Linear Foot ___Inch Plastic Pipe Linear Foot ___Inch Reinforced Concrete Pipe (Jacked) Linear Foot ___Foot x ___Foot Concrete Box Culvert (Precast) Linear Foot ___Inch Steel Safety Grate Each Structure excavation and structure backfill will be measured and paid for per Section 206 except that any void in the structure excavation prism created by the removal of pipe or box culvert will be excluded from measurement and payment of structure excavation. Repair of damaged coatings will not be paid for separately but shall be included in the cost of the item. 603.13 603-6 THIS PAGE INTENTIONALLY LEFT BLANK 604.01 604-1 SECTION 604 MANHOLES, INLETS, AND METER VAULTS DESCRIPTION
604.01 This work consists of the construction of manholes, inlets, and meter vaults per these
specifications, and in conformity with the lines and grades shown on the plans or established. MATERIALS
604.02 Concrete for these structures shall meet the requirements of Section 601 -Structural
Concrete. Other materials shall meet the requirements specified in the following subsections: Clay or Shale Brick 704.01 Concrete Brick 704.02 Concrete Masonry Blocks 704.03 Frames, Grates, Covers, and Steps 712.06 Grade Ring 712.05 Reinforcing Steel 709.01 Precast Concrete Units 712.05 CONSTRUCTION REQUIREMENTS
604.03 Excavation. Excavation shall be per the requirements of Section 206.
604.04 Manholes, Inlets, and Meter Vaults.
a.General. Concrete construction shall conform to the requirements of Section 601. Masonry shall conform to the requirements for the respective type. When specified, the outside face of structures shall be plastered with a 1/2- inch-thick cement -sand mortar coat. Unless otherwise provided, exposed surfaces of concrete and masonry shall be cured as defined in subsection 601.13. Pipe sections on the inside of manholes or inlets shall be treated as shown on the plans, or as directed, and shall project outside sufficiently for proper connection with the next pipe section. Masonry shall fit neatly and tightly around the pipe.
b.Manholes. Wherever directed by the Engineer, pipes of the proper type and size shall be built into a manhole where future laterals are to be connected. These pipes shall be sealed at their outer ends and an invert shall be built into each manhole for such lateral connections. When a manhole is located in the pavement area, it shall not be constructed to final grade until the pavement has been completed.
c.Inlets. Where inlets are placed in existing curbs or gutters, the Contractor shall carefully remove sections of the present curb, gutter, or curb and gutter. All damage to sections to remain in place shall be repaired at the Contractor's expense. The top portion of inlets shall be constructed concurrently with the adjacent curb and gutter to ensure proper alignment of grades unless otherwise permitted in writing.
Source: Colorado Standard Specifications for Road and Bridge Construction, 2023 Edition. Pages 605–610 of 943.