612Siphons

Siphons

612.1DESCRIPTION

1 This section describes the requirements for constructing inverted pipe siphons.

612.2MATERIALS

1 Provide materials in accordance with the following: Material Subsection Admixtures 801.4 Aggregate for Concrete 803 Bolts, Nuts and Washers 815.6 Corrugated Metal Units 808.7 Corrugated Steel Pipe and Pipe-Arches 808.5 Corrugated Steel Siphon Pipe 808.10 Curing Materials 802.1 Fly Ash 801.2 Galvanized Coating 815.14 Joint Materials 807 Portland Cement 801.1 Reinforced Concrete Siphon Pipe 808.3 Reinforcing Steel 811.1 Rubber Gaskets 808.15 Structural Steel 815.1 Water 814 Welded Steel Siphon Pipe 808.11 2 For drain valves, provide solid wedge gate valves with flanged, iron bodies, bronze- mounted, nonrising stems with operating nuts, and a rating of at least 50 psi [345 kPa]. Provide a handle for valve operation.

612.3EQUIPMENT

1 Ensure that equipment meets the following: Equipment Subsection Batch Plant 513.3.1 Mixers 513.3.2 Placing Equipment 513.3.3

Siphons SECTION 612

612.4CONSTRUCTION

612.4.1 Shop Drawings

1 Submit shop drawings for siphon pipe, including recommended installation procedures, to the State Bridge Engineer in accordance with Subsection 105.2, Working Drawings.

2 For reinforced-concrete pipe siphons, ensure that the siphon pipe fabricator calculates the allowable leakage value for acceptance testing in accordance with exfiltration requirements of ASTM C 969 [ASTM C 969M] and converts this value from gallons [liters] of water to a drop in water elevation below the outlet flowline. Include this value with the installation procedures.

612.4.2 Excavation

1 Excavate trenches in accordance with Subsection 206.4.1.1, Culvert Excavation.

612.4.3 Installation of Pipe

1 Prepare bedding in accordance with Subsection 603.4.4, Pipe Bed Preparation, for class C installation. Place bell ends of welded steel siphon pipe and plastic siphon pipe and outside circumferential laps of corrugated steel siphon pipe facing upstream. Place corrugated steel siphon pipe with longitudinal laps at the sides.

2 Install magnesium anodes at specified locations along welded steel pipe siphons to provide cathodic protection. Test for electrical continuity before backfilling.

3 Repair damage to the protective coating of the pipe by priming the areas with approved coal tar paint then applying hot coal tar enamel in accordance with AWWA C203. Do not field-coat damaged parts in air temperatures below 30 °F [0 °C] unless using an approved method of protection and heating.

4 Do not use damaged plastic siphon pipe; the engineer will reject it.

612.4.4 Couplings

1 Use “O-Ring” type couplings for welded steel pipe siphons. Protect field joints by applying primer and wrapping them with two thicknesses of 10-inch [250 mm] wide protective tape.

2 Join corrugated steel siphon pipe by placing concrete collars.

3 For reinforced concrete pipe siphons, use bell-and-spigot couplings with a rubber gasket. Form couplings entirely of concrete with a positive groove in the spigot to contain the gasket.

Siphons SECTION 612

4 When specified, place concrete collars at each joint. Use class B concrete in accordance with Subsection 513.4.4, Mix Design. Form and place concrete in accordance with applicable portions of Subsection 513.4, Construction. Place reinforcing steel in accordance with Section 514, Reinforcing Steel.

612.4.5 Testing

1 Before backfilling over siphon pipe, test the entire installation as follows:

1.1Fill siphon structure with water to the outlet flow line level.

1.2Repair evident leaks, refill to the flow line, and let stand for at least 24 hours.

1.3If there is no apparent water loss during the 24-hour test period, backfill the

trench. If there is water loss, repair leaks and repeat the test.

1.4Where it is impractical to divert traffic around the full length of the siphon

structure, construct, test using the same test head, and backfull a portion of the structure.

2.1Fill the siphon structure with water to the outlet flow line level and let stand

for 24 hours.

2.2Refill to the outlet flow line and let stand for another 24 hours. If the water

level is within the allowable leakage value shown on the shop drawings, backfill the trench.

2.3If the water level is above the allowable water elevation value shown on the

shop drawings, backfill the trench.

2.4If the water level is below the allowable water elevation value as determined

by the fabricator, repair the siphon and repeat the test.

2.5W here it is impractical to divert traffic around the full length of the siphon

structure, construct, test using the same test head, and backfill a portion of the structure. Obtain the maximum acceptable drop in water level for the tested portion from the pipe fabricator, determined in accordance with ASTM C 969 [ASTM C 969M], and have it approved by the State Bridge Engineer.

Siphons SECTION 612 612.4.6 Inlet and Outlet Structures and Drain Boxes 1 When specified, use class B concrete for inlet and outlet structures and drain boxes in accordance with Subsection 513.4.4, Mix Design. Form, place, and cure concrete in accordance with applicable portions of Subsection 513.4, Construction. Place siphon pipe sections flush with the inside of the structure wall and projecting far enough outside to properly connect with the next pipe section. 2 Provide and place reinforcing steel in accordance with Subsection 514.4, Construction. 3 Construct drain boxes with a steel lid and ladder rungs, as specified, to access the drain valve. 4 Provide trash guards, drain box lids, ladder rungs, and other similar steel items in accordance with Subsection 501.4, Construction, and galvanized in accordance with Subsection 501.4.1.25, Galvanizing. 612.

4.7Backfill

1 Place and compact backfill in accordance with Subsection 206.4.5, Backfilling.

612.5MEASUREMENT and PAYMENT

612.

5.1General

1 The engineer will measure:

in [mm], and Welded Stl Siphon Pipe ___ in [mm] by the foot [meter] along the invert from end to end of pipe.

the each for each size specified. 2 The department will pay as follows: Pay Item Pay Unit Measure to the Nearest Pay to the Nearest Corr Stl Siphon Pipe i n [mm] FT [m] 0.1 ft [0.05 m] FT [0.5 m] Corr Stl Siphon FE Sect i n [mm] EA [Ea] EA [Ea] EA [Ea]

Siphons SECTION 612 Pay Item Pay Unit Measure to the Nearest Pay to the Nearest Plastic Siphon Pipe i n [mm] FT [m] 0.1 ft [0.05 m] FT [0.5 m] RCP Siphon i n [mm] FT [m] 0.1 ft [0.05 m] FT [0.5 m] RCP Siphon FE Sect i n [mm] EA [Ea] EA [Ea] EA [Ea] Welded Stl Siphon Pipe i n [mm] FT [m] 0.1 ft [0.05 m] FT [0.5 m] 612.

5.2Referenced Sections for Direct Payment

1 When specified, the engineer will measure and pay for:

ss B Concrete required for constructing inlet and outlet structures and drain boxes in accordance with Section 513, Structural Concrete.

inforcing Steel required for constructing inlet and outlet structures and drain boxes in accordance with Section 514, Reinforcing Steel.

ain box lids, ladder rungs, and similar steel items in accordance with the contract.

ash Guards in accordance with Section 619, Trash Guards.