Aggregate Ditch Art. 283.03 Slope Pin Spacing Steeper than 1:3 (V:H) 2 ft (600 mm) 1:3 (V:H) to 1:4 (V:H) 3 ft (900 mm) Flatter than 1:4 (V:H) 5 ft (1.5 m) Each securing pin shall be pushed through the fabric until the washer bears against the fabric and secures it firmly to the surface. Additional pins, regardless of location, shall be installed as necessary to prevent any slippage of the filter fabric. When the Engineer determines that the proper lap is not being maintained by the use of pins, the fabric shall be sewn according to Article 282.05.
282.07 Protection. The fabric shall be protected during construction from
contamination by surface runoff. Fabric damaged during installation or during placement of riprap shall be replaced or repaired. Repairs shall be made by removing the material around the damage and covering it with a patch of fabric using an overlap of 2 ft (600 mm) in each direction. The patch shall be held in position with securing pins.
282.08 Method of Measurement. This work will be measured for payment in
place and the area computed in square yards (square meters). The buried edges of the fabric will not be measured for payment and the overlap joints and seams will be measured as a single lift of material.
282.09 Basis of Payment. This work will be paid for at the contract unit price
per square yard (square meter) for FILTER FABRIC. SECTION 283. AGGREGATE DITCH
283.01 Description. This work shall consist of furnishing and installing
aggregate in roadside ditches.
283.02 Materials. Materials shall be according to the following.
Item Article/Section
a.Aggregate Ditch ................................................................................. 1005.01
b.Filter Fabric ........................................................................................ 1080.03 CONSTRUCTION REQUIREMENTS
283.03 Aggregate Ditch. The stone aggregate ditch shall be constructed on
filter fabric without any bedding material. The filter fabric shall be constructed according to Section 282, except that the edges along the centerline of the ditch shall be turned down and buried 6 in. (150 mm), the upstream and downstream edges shall be turned down and buried 12 in. (300 mm), and securing pins at overlaps shall be inserted at each edge of the ditch bottom and at intervals of not greater than 5 ft (1.5 m) extending up the slopes. Art. 283.03 Gabions and Slope Mattress The aggregate lift shall be a minimum of 12 in. (300 mm) thick and placed to the lines and grades as shown on the plans, or as directed by the Engineer. The placement of the aggregate shall begin at the lower elevation and proceed up the slope in such manner to construct a reasonably well graded mass of stone free from objectionable pockets of small stones and clusters of large stones. Arranging of stones may be required to the extent necessary, either mechanically or by hand, to obtain a well graded distribution of stone sizes and grade lines. Disturbed soil surfaces not covered with stone aggregate shall be seeded, fertilized and mulched according to Sections 250 and 251.
283.04 Method of Measurement. Aggregate ditch will be measured for
payment in tons (metric tons) according to Article 311.08(b). Filter fabric will be measured for payment according to Article 282.08.
283.05 Basis of Payment. This work will be paid for at the contract unit price
per ton (metric ton) for AGGREGATE DITCH. Filter fabric will be paid for according to Article 282.09. SECTION 284. GABIONS AND SLOPE MATTRESS
284.01 Description. This work shall consist of furnishing and placing a
protective course of stone confined by wire baskets used as retaining walls, slope paving, bank protection, weirs, drop structures, or outfall structures.
284.02 Materials. Materials shall be according to the following.
Item Article/Section
a.Stone for Erosion Control (Note 1) ..................................................... 1005.01
b.Gabions and Slope Mattresses .......................................................... 1006.35
c.Wire Fasteners .................................................................................. 1006.36
d.Anchor Stakes .................................................................... 1006.04, 1006.18
e.Filter Fabric ........................................................................................ 1080.03 Note 1. The stone shall conform to the requirements of Quality Designation A and shall not contain objectionable quantities of dirt, sand, clay, or rock fines. The stone shall be well graded with maximum stone dimensions ranging between 4 to 8 in. (100 to 200 mm). No stone shall have a minimum dimension less than 3 in. (75 mm), and the ratio of maximum to minimum dimension shall not be greater than two. CONSTRUCTION REQUIREMENTS
284.03 Fabricating Gabions and Slope Mattresses. Baskets shall be
fabricated in such a manner that the sides, ends, lid, and diaphragms can be assembled at the construction site into rectangular baskets of the sizes specified and shown on the plans. Baskets furnished by the manufacturer shall be of uniform size. Baskets shall be of single unit construction, i.e., the base, lid, ends, and sides shall be either woven into a single unit or one edge of these members connected to the
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Source: Illinois Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 152–153 of 1,217. View official source ↗