092311 — Riprap Ditches

311.01 Description

Construct riprap ditches and riprap ditches with capping.

311.02 Materials

Riprap 901.02 and 901.03 Geotextile Section 919, Class as specified 2 in. to 4 in. Stone M 43, No. 1

311.03 Construction

311.03.01 Excavation. Excavate to the specified line and grade. Ensure that ditch sides and

bottom are smooth and firm, free from protruding objects that would damage the geotextile, and constructed in an acceptable manner. For excavated material, refer to 402.03.01.

311.03.02 Geotextile Placement. Place geotextile on the prepared subgrade with the adjacent

edges overlapped at least 2 ft. Replace or repair damaged geotextile as directed. 311.03.03 Riprap Placement. Place stones by mechanical or other acceptable methods to produce a reasonably graded mass of stone. Methods that cause extensive segregation are unacceptable. Place the riprap to the specified depth.

311.03.04 Backfill. Backfill any excavation voids existing along the edges and ends of the placed

riprap. Use suitable material to blend in with contiguous slopes, ditch lines, and existing ground. Cap riprap placed in the clear recovery area with a layer of 2 in. to 4 in. stone.

311.04 Measurement and Payment

The payment will be full compensation for all excavation, geotextile, stone, backfill, disposal of excess material, and for all material, labor, equipment, tools, and incidentals necessary to complete the work.

311.04.01 Riprap Ditches and Riprap Ditches with Capping will be measured and paid for at the

Contract unit price per square yard of finished surface. 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS

311.04.02 Bottom Cutoff Walls and Side Cutoff Walls will be measured and paid for at the

Contract unit price per linear foot. 312 — RIPRAP SLOPE AND CHANNEL PROTECTION CATEGORY 300 DRAINAGE SECTION 312 — RIPRAP SLOPE AND CHANNEL PROTECTION

312.01 Description

Protect slopes and channels with a covering of geotextile and riprap or an aggregate filter blanket.

312.02 Materials

Aggregate Filter Blanket 901.01, CR-6 Riprap 901.02 Geotextile Section 919, Class as specified

312.03 Construction

312.03.01 Excavation. Excavate for riprap and cutoff walls to the specified lines and grades.

Ensure that the subgrade is smooth and firm, free from protruding objects that would damage the geotextile, and constructed in an acceptable manner. For excavated material, refer to 402.03.01.

312.03.02 Geotextile. Place geotextile on the prepared subgrade with the adjacent edges

overlapping at least 2 ft. Replace or repair damaged geotextile as directed. 312.03.03 Aggregate Filter Blanket. When an aggregate filter blanket is specified, construct it to the specified lines and grades and compact it in an acceptable manner. 312.03.04 Riprap Placement. Ensure that the underlying surface is free of brush, trees, and stumps, and is acceptable to the Engineer. Place the first section of riprap consisting of at least 5 tons, which will be inspected by the Engineer for conformance to gradation and placement requirements. If approved, this section will be used to evaluate quality control for the remainder of the project. If the material is rejected, remove it from the project and place additional sections, each at least 5 tons. Begin the placement of the riprap with the bottom cutoff walls or toe sections. Place the larger stones in the cutoff walls and along the outside edges of the limits of slope and channel protection. Place the riprap with equipment that produces a uniformly graded mass of stones. Ensure that the surface elevation of completed riprap installations is flush with adjacent channel bed or bank slope elevations and does not create an obstacle to the flow. Ensure that the outer 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS