611.02 Manholes , Drop Or Curb Inlets, and Junction Boxes
548 SECTION 611
611.01 Description
This work consists of constructing manholes, drop or curb inlets, junction boxes, or similar structures using precast concrete units, brick masonry, or cast -in-place concrete.
611.02 Materials
A.General Provide materials in accordance with the following section and subsections : Material: Section or Subsection: Portland Cement 701.02 Mortar Sand 701.05 Clay Brick 714.01 Concrete Brick 714.02 Structural Steel 724 Steel Castings 725.02 Iron Castings 725.03 Precast Manholes 726.01 Portland Cement Concrete Class A 701.01 The Department will allow precast concrete u nits instead of brick masonry or cast -in-place concrete unless otherwise shown on the Plans, except, the Department will not allow brick masonry for the construction or rebuilding of sanitary sewer manholes. Provide two T-handles for up to the first 20 locking manhole covers and one for each additional 20 locking manhole covers.
B.Portland Cement Mortar With brick masonry, provide mortar composed of one part portland cement and two parts mortar sand by volume, mixed with water to form a plastic consistency . Do not substitute more than 10 percent of the cement, by volume, with hydrated lime. Add the hydrated lime to the cement first.
C.Accessories Provide first -quality standard commercial material free of defects for accessories such as bolts, rivets, spa cers, small I-beams, channels, and plates for assembling or supporting frames, grates, or covers, MANHOLES, DROP OR CURB INLETS, AND JUNCTION BOXE S 611.04 549 611.03 EQUIPMENT Provide specialized equipment capable of off -loading, handling, and placing the largest single unit, subassemblies, or both. Provide lift holes or lift rings in each unit in accordance with the manufacturer’s recommendation. Ensure lift devices and connection points are safe for handling above ground and in the inlet excavation.
611.04 Construction Methods
A.Concrete When constructing conc rete bottoms for manholes and inlets, round the concrete to the dimensions and shape indicated. Trowel the surface to obtain a uniform, smooth, and impervious hard -fanned finish. Ensure exposed concrete edges have at least a ½ in [13 mm] chamfer, or a rou nded edge. Finish exposed concrete surfaces in accordance with Subsection 509.04.G, “Finishing Formed Concrete Surfaces.”
B.Clay Brick or Concrete Brick Install stretchers every fifth course and headers for the rema inder for brick masonry used in circular or curved walls with radii less than 2 ft [0.6 m]. Ensure the thickness of the joints does not exceed ¼ in [6 mm] vertical on inside faces or ⅜ in [10 mm] on horizontal faces. For brick masonry used in both straig ht and curved walls with radii at least 2 ft [0.6 m], install headers every fifth course and stretchers for the remainder. Ensure the thickness of the joints does not exceed ⅜ in [10 mm]. Construct vertical joints in subsequent courses half the length or width of the brick. Lay the brick in a full bed of mortar and construct shoved joints. The Department will not allow buttered joints. For joints on the inside or exposed face of the masonry, rub the joints fully and cut as the brickwork is built up. Bui ld up the masonry in level courses true to the lines, grades, and dimensions shown on the Plans. Use bats to close joints around irregular openings as directed by the Resident Engineer. Thoroughly wet the brick immediately before placing. Clean and wet old brick masonry before joining new masonry to it. If the Contract requires a mortar coating, apply to the minimum thickness shown on the Plans. Apply the mortar coat while the brick masonry is clean and damp, then trowel to a uniform, smooth, imperviou s surface.
C.Pipe Connections Use inlet and outlet pipe of the size shown on the Plans or as directed by the Resident Engineer. Ensure the end of the pipe is flush with the inside of the wall and tightly seal the circumference of the pipe in the wall wit h mortar. Remove the lip of the female end of the pipe, and press in and trowel the mortar flush with the face of the wall.
D.Special Curb Use the same type of concrete as the regular curb if building curbs adjacent to sewer inlets or Class A concrete wh ere no regular curb is being built. Accurately shape the forms for the curb opening
611.04 Manholes , Drop Or Curb Inlets, and Junction Boxes
550 to the dimensions and at the locations shown on the Plans. Ensure the forms remain in place for at least 3 days to cure the concrete, or longer as directed by the Residen t Engineer.
E.Reinforcing Steel Place reinforcing steel in accordance with Section 511, “Reinforcing Steel for Structures.”
F.Castings, Grate, and Drop Inlet Grates and Special Frames Assemble and place castings, grates, specia l frames, and supports as shown on the Plans. Bed the frames of manholes and covers, and inlets and grates in a layer of mortar with a full bearing and set to the grade shown on the Plans. Make the top of the casting flush with the surrounding surface unl ess otherwise indicated. Finish exposed surfaces of special structural steel frames and supports in accordance with Section 506, “Structural Steel.”
G.Excavation and Backfill Excavate to the depth shown on the Plans and compact the base for manholes, inlets, or junction boxes to a firm, even surface. Replace unsuitable material with suitable material and compact as directed by the Resident Engineer.
H.Precast Units Bed precast concrete units on a solid foundation at least 2 in [50 mm] thick that consists of clean, uniformly graded material capable of being mechanically leveled, leveled by flooding, or floated on a lean grout. Do not allow the presence of clay balls or cement clumps. If using sand flooding or grout pouring for b edding, backfilling, or both, securely anchor each unit to prevent lateral or vertical movement. Immediately after placement, backfill inlet excavation and compact using incremental layers or sand flooding. Place entrance and exit conduits (round, oval, e lliptical, arch pipe or concrete box) with flowlines as shown on the Plans. Do not allow alterations of the elevation or angle to facilitate ease of installation or to use an existing blockout. Set precast concrete inlet units flush with, or slightly below , the subgrade to prevent interference with the movement of the paving equipment. If precast concrete inlet assemblies are set at subgrade elevation, use a bedded brick (fired clay or concrete) leveling course to bring the inlet assembly to the final grad e shown on the Plans. The Department will allow a formed and poured concrete collar. Pin the concrete collar to the inlet box and additional opening boxes as approved by the Resident Engineer. Ensure precast concrete units provide a soil -tight connection between subassemblies and at each entrance or exit conduit blockout. If a unit is delivered with a blockout placed in error, or if a Plan revision renders a blockout unnecessary, clean the hole and fill with a concrete patch. For blockou ts, MANHOLES, DROP OR CURB INLETS, AND JUNCTION BOXES 611.05 551 the Department will allow a patch from a previous blockout hole securely grouted in place or poured, or placed using a dry -mix high -strength concrete. Provide gasket material for use between subassemblies or between the inlet unit and entrance or exit conduits, in accordance with the Materials Division’s “Approved Products List” for adhesive materials. Seal the joints and base of precast manholes in accordance with Subsection 613.04.E, “Outlet Lateral Headwalls,” to prevent water passage; except, make joints with a single natural rubber or neoprene gasket or O-ring in accordance with the manufacturer’s recommendations.
611.05 Method of Measuremen T
A.Manhole The Resident Engineer will measure each Manhole as includi ng the concrete bottom and up to 5 ft [1.5 m] of wall, measured from the bottom of the frame cover casting to the flowline of the outlet conduit.
B.Additional Depth in Manhole The Resident Engineer will measure the depth of wall in excess of 5 ft [1.5 m] for Additional Depth of Manhole , in accordance with Subsection 611.05.A, "Manhole."
C.Special Manhole The Resident Engineer will measure Special Manhole by the volume of 8 in [200 mm] thick wall constructed and mak e deductions for openings. The Resident Engineer will measure the concrete bottom in accordance with Section 509.05, “Method of Measurement.”
D.Inlet The Resident Engineer will measure each Inlet by the number of inle ts provided for each type and design as shown on the Plans.
E.Additional Depth in Inlet The Resident Engineer will measure the depth of single or double inlet boxes and additional curb opening boxes in excess of the minimum depth shown on the Plans for Additional Depth in Inlet .
F.Junction Boxes The Resident Engineer will measure the volume of 8 in [200 mm] thick wall for Junction Boxes and make deductions for pipe openings with diameters greater than 18 in [450 mm].
611.06 Manholes , Drop Or Curb Inlets, and Junction Boxes
552 611.06 BASIS OF PAYMENT The Departm ent will pay for each pay item at the contract unit price per the specified pay unit as follows: Pay Item: Pay Unit:
A.MANHOLE Each
B.ADDITIONAL DEPTH IN MANHOLE Vertical Foot [Meter]
C.REPLACEMENT OF MANHOLE FRAME AND COVER Each
D.REPLACEMENT MANHOLE FRAME Each
E.REPLACEMENT OF MANHOLE COVER Each
F.REPLACEMENT OF MANHOLE COVER GRATE Each
G.INLET Each
H.ADDITIONAL DEPTH IN INLET Vertical Foot [Meter]
I.REPLACEMENT OF INLET FRAME AND GRATE Each
J.REPLACEMENT OF INLET FRAME Each
K.REPLACEMENT OF INLET GRATE Each
L.JUNCTION BOXES Cubic Foot [Meter]
M.REPLACEMENT OF CAST IRON HOOD Each
N.WELDED STEEL GRATE Each Include the cost of the following to be included in the contract unit price for the relevant pay items: Excavation, Backfill, Reinforcing steel, Frames, Covers, Grates, Cast Iron Hoods, Support beams, Support beams with riser plates, Bolts, Nuts, and T-handles for locking manhole covers. ADJUSTMENT OF EXISTING STRUCTURES 612.04 553 SECTION 612 ADJUSTMENT OF EXISTING STRUCTURES
612.01 Description
This work consists of adjusting, altering, relocating, resetting, and realigning existing structures, equipment, or appurtenances. This applies to public structures shown on the Plans to remain.
612.02 Materials
Provide materials of an equivalent grade to the existing structure, as shown on the Plans, or materials required by the Contract for similar work.
612.03 Equipment — Vacant
612.04 Construction Methods
A.General Refurbish and reset Department -provided electrical equipment, including delivering the equipment to the project if required by the Contract. Adjust, reset, or rebuild existing structures to the final grade shown on the Plans, or as approved by the Resident Enginee r. Make adjustments to existing structures in pavement after placing the final surface course. Protect the altered, removed, or reset structure or appurtenance during transport and adjustment. Repair or replace unprotected items damaged during transport or adjustment at no additional cost to the Department. Transport items from the storage site, and reset at no additional cost to the Department. Modify, clean, or repair the structure or appurtenances before resetting as shown on the Plans.
B.Manholes If the Contract requires the tops of the manholes to be lowered to a new grade, remove the walls and rebuild manholes so the maximum batter of the walls does not exceed 4 in/ft [330 mm/m]. Construct the walls vertically from the top of the batter section if the Contract requires manholes to be raised 1 ft [300 mm] or less to the new grade. If the Contract requires manholes to be raised more than 1 ft [300 mm] to the new grade, remove the walls to the bottom of the batter section, or to an elevation at which the inside diameter of the manhole is at least 3 ft [0.9 m] and rebuild in accordance with Section 611, "Manholes, Drop or Curb Inlets, and Junction Boxes."
C.Inlets and Manholes Reset or rebuild inlets, manholes, or similar str uctures to the grade shown on the Plans in accordance with Section 611, "Manholes, Drop or Curb Inlets, and Junction Boxes."
Source: Oklahoma Standard Specifications for Highway Construction, 2019 Edition. Pages 562–566 of 935.