2-32 Section 275
275-1 Description
Place rip rap on slopes in accordance with the contract. Rock plating is required to stabilize slopes at locations shown in the plans and as directed by the Engineer .
275-2 Materials
Refer to Division 10. Item Section Geotextile for Rock Plating, Type 2 1056 Plain Rip Rap 1042 Select Material, Class IV 1016 Subsurface Drainage Materials 1044 Provide Type 2 geotextile for filtration geotextiles . Use Class IV s elect material (standard size No. ABC) over rip rap and Class 1, 2 or B rip rap unless required otherwise in the plans. Provide subdrain coarse aggregate (standard size No. 78M) and PVC subdrain pipes, fittings and outlet pipes for subsurface drainage materials.
275-3 Construction Methods
Construct embankments in accordance with the contract. Compact fill slopes to the satisfaction of the Engineer with tracked equipment or other approved met hods. Excavate materials as need to install rock plating on cut slope faces or embed rock plating below the ground line. Do not leave filtration geotextile s exposed for more than 7 days before covering with rip rap or ABC. Unroll geotextile s down slopes, i.e., perpendicular to the roadway centerline. Bury filtration geotextile s at top of slopes and embed geotextile s at toe of slopes as shown in the plans. Filtration geotextile s should be continuous down slopes. I f geotextile roll length is too short, overlap ends of geotextile rolls at least 5 f eet with the upper geotextile over the lower as shown in the plans. Filtration geotextile s may be discontinuous down slopes in the direction perpendicular to the roadway centerline only once per roll width. Overlap adjacent filtration geotextile s along slopes at least 18 inches as shown in the plans. Pull geotextile s taut so that they are in tension and free of kinks, folds, wrinkles or creases. Hold geotextiles in place as needed wi th wire staples or anchor pins. Do not displace or damage filtration geotextile s while placing rip rap. When shown in the plans, install 6 inch diameter perforated subdrain pipes and No. 78M stone at toe of slopes in accordance with
Article 815 — 3.
Place r ip rap so smaller stones are uniformly distributed throughout rip rap. Install rip rap with mechanical methods and if necessary, by hand to form a well graded, dense, neat layer of rip rap. When shown in the plans, place filtration geotextile s and 18 inches of ABC over rip rap at top of slopes. Compact ABC to 92% of AASHTO T 180 as modified by the Department or to the highest density that can be reasonably obtained.
275-4 Measurement and Payment
Rock Plating will be measured and paid in square yards. Rock plating will be measured along slope faces of rock plated slopes as the square yards of exposed rip rap and if applicable, ABC. No measuremen t will be made for portions of rock plating embedded below the ground line. The contract unit price for Rock Plating will be full compensation for providing, transporting and installing filtration geotextile s, wire staples, anchor pins, rip rap and ABC.
2-33 The contract unit price for Rock Plating will be full compensation for excavating materials to
install rock plating on cut slope faces and embed rock plating below the ground line. Subdrain Coarse Aggregate and __" Perforated Subdrain Pipe will be measured and paid in accordance with Article 815-4. Payment will be made under: Pay Item Pay Unit Rock Plating Square Yard