ITEM 518 DRAINAGE OF STRUCTURES
518.01
Description
518.02
Fabrication
518.03
Materials
518.04 General
518.05 Porous
Backfill
518.06 Pipe
518.07 Scuppers
518.08
Excavation
518.09 Method
of Measurement
518.10 Basis of
Payment
518.01 Description. This work consists of
constructing drainage systems.
518.02 Fabrication. Fabricate scuppers
according to Item 513. Select a fabricator that is
at least pre-qualified at level SF. The Department will base final
acceptance of all fabricated members on the Engineer’s approval that the
fabricated items can be successfully incorporated into the structures.
Submit mill test reports for structural steel, steel castings, bronze, and
sheet lead certified according to 501.06.
518.03 Materials. Furnish materials conforming to:
Scuppers, structural steel
and cast steel......................... 513
Metal
pipe..................................................................... 707
Plastic
pipe.................................................. 707.33, 707.45
Other
metals.................................................................. 711
Filter fabric, Type A................................................ 712.09
Furnish
pipe specials of a grade at least as high as the type of pipe specified.
Furnish
porous backfill consisting of gravel, stone, or air-cooled blast furnace slag,
with a No. 57 size gradation according to Table 703.01-1. The sodium sulfate
soundness loss shall not exceed 15 percent.
Furnish
ACBF slag conforming to Supplement
1027.
518.04 General. As shown on the plans, connect
all parts to new or existing sewers or other outlets.
When
installing to superstructure, take into account the deflection of spans under
full dead load.
518.05 Porous Backfill. Place porous backfill as
shown on the plans. When not shown on the plans, place backfill at
least 2 feet (0.6m) thick behind the full length of abutments, wing
walls, and retaining walls. Measure the thickness of porous backfill
normal to the abutment or wall face. The Contractor may leave undisturbed
rock or shale within 18 inches (0.5 m) of the abutment or wall. Place 2 ft³ (0.23 m³) of bagged No. 3 aggregate at each weep hole
to retain the porous backfill. Place the porous backfill for the
full width of the trench and extend it to the bottom of the approach slab or
base, as shown in the plans. .
518.06 Pipe. For drain pipe leading down from
the superstructure, use either galvanized steel pipe, 748.06; or plastic pipe, 707.45. Provide specials, elbows,
tees, wyes, and other fittings essential for a complete and satisfactory
installation of the same material and quality as the pipe. Construct
watertight joints of adequate strength. In steel pipe, weld joints or use
clamp-type couplings having a ring gasket. In plastic pipe, make joints
according to the applicable ASTM standard. Securely fasten the pipe to
the structure with hanger or clamp assemblies that are galvanized according to 711.02.
Place
subsurface pipe as shown in the plans.. If the
plans require drainage pipe in the porous backfill, provide plastic pipe
conforming to 707.33.
For
corrugated metal pipe, perforated specials are not required and the Contractor
may make bends with adjustable elbows conforming to the thickness requirements
of the pipe specifications.
518.07 Scuppers. Construct secure and watertight
connections, including the connections to adjacent concrete. Provide
castings, true to form and dimension. Weld the joints of structural steel
scuppers. Galvanize scuppers according to 711.02.
518.08 Excavation. Excavate all material encountered
to the dimensions necessary to provide ample space at least to install pipe or
other drainage facility behind abutments and for outlets.
518.09 Method of Measurement. The
Department will measure Porous Backfill and Porous Backfill with Filter Fabric
by the number of cubic yards (cubic meters) or lump sum. The Department
will measure pipe specials by the same method as the pipe. If pipe is by
the foot (meter), the Department will measure the pipe along its centerline.
518.10 Basis of Payment. The cost
to backfill, if not separately itemized in the Contract, and excavation is
incidental to the drainage facility that necessitates them.
The
Department will include bagged aggregate with porous backfill for
payment.
The Department
will pay for accepted quantities at the contract prices as follows:
Item
Unit
Description
518
Cubic
Yard
Porous Backfill
(Cubic Meter) or
Lump Sum
518
Cubic Yard
Porous Backfill with Filter Fabric
(Cubic Meter)
or
Lump Sum
518
Foot
(Meter)
___ inch (___ mm) ___ Pipe, Including Specials
518
Each
Scuppers, Including Supports
518
Pound or
Foot
Trough Horizontal Conductors
(Kilogram or Meter)
518
Pound or
Foot
Pipe Horizontal Conductors
(Kilogram or Meter)
518
Foot
(Meter)
___ inch (___ mm) Pipe Downspout Including Specials