Article 1 — Description
Construct junction boxes, manholes , and inlets, complete in place or to the stage detailed, including furnishing and installing frames, grates, rings, and covers.
Article 2 — Materials
Furnish materials in accordance with the following. Item 420, “Concrete Substructures” Item 421, “Hydraulic Cement Concrete” Item 440, “Reinforcement for Concrete” Item 471, “Frames, Grates, Rings, and Covers” Cast-in-place junction boxes, manholes, inlets, risers, and appurtenances are acceptable unless otherwise shown on the plans . Alternat e designs for cast -in-place items must be acceptable to the Engineer and must conform to functional dimensions and design loading. Alternate designs must be designed and sealed by a licensed professional engineer.
2.1 Concrete. Furnish concrete in accordance with DMS -7305 , “Fabrication and Qualification Procedure for
Multi- Project Fabrication Plants of Precast Concrete Drainage Structures,” for formed and machine- made precast junction boxes, manholes, and inlets. Furnish Class C concrete for cast -in-place junction boxes, manholes, and inlets unless otherwise shown on the plans .
2.2 Mortar . Furnish mortar conforming to DMS -4675 , “Cementitious Grouts and Mortars for Miscellaneous
Applications.”
2.3 Timber . Provide sound timber that is at least 3-in. nominal thickness and reasonably free of knots and warps
for temporary covers when used with Stage I construction . (Refer to Article 465.3., “Construction. ”)
2.4 Other Materials. Use commercial -type hardware as approved.
Article 3 — Construction
Construct all types of junction boxes, manholes, and inlets either complete or in two stages, described as Stage I and Stage II. Construct the Stage I portion of junction boxes, manholes, and inlets as shown on the plans or as specified in this Item. Furnish and install a temporary cover as approved. Furnish and install the storm drain pipe and a temporary plug for the exposed end of the storm drain pipe from the storm drain to a point below the top of curb indicated on the plans for Stage I construction of cast iron or steel inlet units. Construct Stage II after the pavement structure is substantially complete, unless otherwise approved. Construct the remaining wall height and top of junction box, manhole, or inlet for Stage II, and furnish and install any frames, grates, rings and covers, curb beams, or collecting basins required. 726 Construct cast -in-place junction boxes, manholes, and inlets in accordance with Item 420. Forms are required for all concrete walls. Outside wall forms for cast -in-place concrete may be omitted with approval if the surrounding material can be trimmed to a smooth vertical face.
3.1 Precast Junction Boxes, Manholes, and Inlets. Construct formed and machine- made precast junction
boxes, manholes , and inlets in accordance with DMS -7305 and as shown on the plans, excep t as otherwise specified in this Item. Multi- project fabrication plants as defined in DMS -7305 that produce junction boxes, manholes, and inlets will be approved by the Materials and Tests Division in accordance with DMS -7305 . The Department’s MPL has a list of approved multi -project junction box, manhole, and inlet fabrication plants .
3.1.1 Marking . Clearly mark each precast junction box, manhole, and inlet unit with the following information:
name or trademark of fabricator and plant location, product designation, ASTM designation (if applicable), date of manufacture, designation “TX” for precast units fabricated in accordance with DMS -7305 , designated fabricator’s approval stamp for each approved unit, and designation “SR” for product meeting sulfate- resistant concrete plan requirements (when applicable).
3.1.2 Defects and Repair . Repair precast junction boxes, inlets, and manholes, if necessary, in accordance with
the Annex of DMS -7305 . Precast junction boxes, inlets, and manholes may be rejected for any of the conditions stated in this Annex .
3.1.3 Storage and Shipment . Store precast units on a level surface. Do not ship units until design strength
requirements have been met.
3.2 Excavation, Shaping, Bedding, and Back fill. Excavate, shape, bed, and backfill in accordance with
Item 400, “Excavation and Backfill for Structures.” Immediate backfilling is permitted for all junction box, manhole, and inlet structures where joints consist of rubber boots, rubber gaskets, or bulk or preformed joint sealant. Take precautions in placing and compacting the backfill to avoid any movement of junction boxes, manholes, and inlets. Remove and replace junction boxes, manholes, and inlets damaged by the Contractor at no expense to the D epartment.
3.3 Junction Boxes, Manholes, and Inlets for Precast Concrete Pipe Storm Drains. Construct junction
boxes, manholes, and inlets for precast concrete pipe storm drains before completion of storm drain lines into or through the junction box, manhole, or inlet. Neatly cut all storm drains at the inside face of the walls of the junction box, manhole, or inlet.
3.4 Junction Boxes, Manholes, and Inlets for Box Storm Drains. Place bases or risers of junction boxes, manholes, and inlets for box storm drains before or in conjunction with placement of the storm drain. Backfill
the junction box, manhole, or inlet and storm drain as a whole.
3.5 Inverts. Shape and route floor inverts passing out or through the junction box, manhole, or inlet as shown on the plans. Shape by adding and shaping mortar or concrete after the base is placed or by placing the required additional material with the base.
3.6 Finishing Complete Junction Boxes, Manholes, and Inlets . Complete junction boxes, manholes, and
inlets as shown on the plans. Backfill to original ground elevation in accordance with Item 400.
3.7 Finishing Stage I Construction. Complete Stage I construction by constructing the walls to the elevations shown on the plans and backfilling to required elevations in accordance with Item 400.
727 3.8. Stage II Construction . Construct subgrade and base course or concrete pavement over Stage I junction box, manhole, or inlet unless otherwise approved. Excavate to expose the top of Stage I construction and complete the junction box, manhole, or inlet as shown on the plans and in accordance with these specifications, including backfill and cleaning of all debris from the bottom of the junction box, manhole, or inlet.
3.9 Inlet Units . Install cast iron or steel inlet units in conjunction with the construction of concrete curb and
gutter. Set the inlet units securely in position before placing concrete for curb and gutter. Form openings for the inlets and recesses in curb and gutter as shown on the plans. Place and thoroughly consolidate concrete for curb and gutter adjacent to inlets and around the inlet castings and formed openings and recesses without displacing the inlet units.
Article 4 — Measurement
All junction boxes, manholes, and inlets satisfactorily completed as shown on the plans and in conformance with specificat ions will be measured by each junction box, manhole, or inlet complete, or by each junction box, manhole, or inlet completed to the stage of construction required by the plans.
Article 5 — Payment
The work performed and materials furnished in accordance with this Item and measured as provided under “Measurement” will be paid for as follows .
5.1 Complete Manholes . Payment for complete manholes will be made at the unit price bid for “Manhole
(Complete)” of the type specified.
5.2 Complete Inlets . Payment for inlets will be made at the unit price bid for “Inlet (Complete)” of the type
specified.
5.3 Complete Junction Boxes . Payment for junction boxes will be made at the unit price bid for “Junction Box
(Complete)” of the type specified.
5.4 Manholes Stage I . Payment for m anholes, Stage I, will be made at the unit price bid for each “Manhole
(Stage I)” of the type specified.
5.5 Manholes Stage II . Payment for m anholes, Stage II, will be made at the unit price bid for each “Manhole
(Stage II)” of the type specified.
5.6 Inlets Stage I . Payment for i nlets, Stage I, will be made at the unit price bid for each “Inlet (Stage I)” of the
type specified.
5.7 Inlets Stage II . Payment for i nlets, Stage II, will be made at the unit price bid for each “Inlet (Stage II)” of the
type specified.
5.8 Junctio n Boxes Stage I . Payment for j unction boxes, Stage I, will be made at the unit price bid for each
“Junction Box (Stage I)” of the type specified.
5.9 Junction Boxes Stage II . Payment for j unction boxes, Stage II, will be made at the unit price bid for each
“Junction Box (Stage II)” of the type specified. These price s are full compensation for concrete, reinforcing steel, mortar, frames, grates, rings and covers, excavation, and backfill , and for all other materials, tools, equipment, labor, and incidentals .