Unless otherwise shown on the plans, the riprap shall extend from 2 feet below the bed of a stream to the apparent high water line.

619.04 Dumped Riprap. Stone for riprap shall be placed on the prepared slope or area in a manner which will produce a resonably well-graded mass of stone with the minimum practicable percentage of voids. Riprap shall be placed to its full course thickness at one operation and in such a manner as to avoid displacing the underlying material. Placing of riprap in layers, or by dumping into chutes, or by similar methods likely to cause segregation, will not be permitted.

Hand placing or rearranging of individual stones by mechanical equipment may be required to the extent necessary to secure the results specified.

619.05 Wire-Enclosed Riprap. The plans and special provisions will show details of wireenclosed riprap and specify the construction procedure to be used.

619.06 Grouted Riprap. The stones shall be placed on the prepared slope substantially to the dimensions shown on the plans. The stones shall be thoroughly moistened and any excess of fines shall be sluiced to the underside of the stone blanket before grouting.

The grout may be delivered to the place of final deposit by any means that will insure uniformity and prevent segregation of the grout. If penetration of grout is obtained by gravity flow into the interstices, the grout will be spaded or rodded into the interstices to completely fill the voids in the stone blanket. Pressure grouting shall not unseat the stones; and after placing by this method, the grout shall be spaded or rodded into the voids.

Weep holes shall be provided through the blanket as shown on the plans or as directed by the Engineer. Where the depth specified for grouting is in excess of 12 inches, such as cutoff walls, the riprap shall be placed in lifts of 12 inches or less and each lift shall be grouted prior to placing the next lift. The succeeding lifts shall be constructed and grouted before the grout in the previous lift has hardened.

Grout shall be placed only when the temperature is above 35°F. and rising. It shall be protected from freezing and cured as specified in Section 610.

619.07 Concrete Riprap in Bags. Cloth cement sacks about two-thirds filled and securely tied, or burlap grain sacks containing about 1⁄2 cubic feet of concrete and folded at the top, are immediately placed in position after filling. When the protected slope is 1-2:1 or steeper, a bed consisting of two rows of sacks placed as stretchers shall be followed by a row of sacks placed as headers. Succeeding rows of sacks shall be placed as stretchers with joints between sacks staggered. Each sack shall be hand placed and pushed into firm contact with adjacent sacks. On slopes flatter than 1-2:1 all rows after the bed row shall be placed as headers.

Cutoffs and weep holes shall be placed as shown on the plans or as directed by the Engineer. The finished work shall present a neat appearance with parallel rows of sacks, and no sacks shall protrude more than 3 inches from the finished surface.

The riprap shall be placed only when the temperature is above 35°F. and rising. It will be protected from freezing and given a water cure for three days.

Whenever placement of concrete riprap in bags is delayed sufficiently to affect the bond between succeeding courses, a small trench about half the depth of a sack shall be excavated back of the last row of sacks in place and the trench filled with fresh concrete before the next layer of sacks is laid. At the start of each day's work, or when a delay of over 2 hours occurs during the placing of successive layers of sacks, the previously placed sacks shall be moistened and dusted with cement to develop bond.

619.08 Concrete-Slab Riprap. Slabs of the dimensions and type, plain or reinforced, shown on the plans shall be poured in place with class B concrete unless otherwise specified. Alternate slabs shall be poured and the remaining panels shall be poured later.

Unless otherwise specified, the slabs shall be laid in horizontal courses and successive courses shall break joints with the preceding ones. Horizontal joints shall be normal to the slope and shall be cold joints without filler. The joints extending up the slope shall be formed with 3/4-inch lumber, which shall be removed and the joint left open. The slabs shall be finished with a wood float.

The pouring and curing shall be carried out as specified for class B concrete in Section 552. 619.09 Filter Blanket. When required, a filter blanket shall be placed on the prepared slope or area to the full specified thickness of each layer in one operation, using methods which will not cause segregation of particle sizes within the bedding. The surface of the finished layer should be reasonably even and free from mounds or windrows. Additional layers of filter material, when required, shall be placed in the same manner, using methods which will not cause mixture of the material in the different layers.

Method of Measurement

619.10 The quantity of riprap to be paid for will be the number of cubic yards, measured in place, or tons of riprap, completed and accepted.

Filter blanket material will be measured by the cubic yard in final position or by the ton completed in place and accepted.

Basis of Payment

619.11 The quantities, determined as provided above, will be paid for at the contract price per unit of measurement, respectively, for each pay item listed below that is shown in the bid schedule, which prices and payment will be full compensation for the work of this section, including trench excavation; the preparation of the subgrade; the placing of the filter blanket when required; the placing of the stone; the grouting when required; furnishing steel for reinforced concrete-slab riprap; and all other work incidental to finished construction in accordance with these specifications.

When the bid schedule does not contain an estimated quantity for filter blanket the work will not be paid for directly but will be considered as a subsidiary obligation of the Contractor covered under other contract items.

620.01 This work shall consist of hand-laid or derrick-placed rock embankment, as designated in the bid schedule, constructed in accordance with these specifications and in reasonably close conformity with the lines and grades shown on the plans or established by the Engineer.

Materials

620.02 Stones shall be sound and durable and furnished in a well-balanced range of sizes meeting the requirements herein.

Unless otherwise provided by the plans or special provisions, all stones shall be more than 2 cubic foot in volume. For hand-laid embankment not less than 75 percent of the total volume of rock embankment shall consist of stones more than 1 cubic foot in volume. For derrick-placed embankment, not less than 50 percent of the total volume of rock embankment shall consist of stones at least 12 cubic feet in volume as visually determined by the Engineer or by physical measurements.

Construction Requirements

620.03 A foundation bed shall be excavated in accordance with Section 206, or as directed by the Engineer.

Stones shall be laid flat on firm beds and securely placed, with broken joint lines. The larger stones shall generally be located in the lower part of the structure and voids shall be eliminated to the extent possible. Spalls smaller than the minimum stone-size specified in subsection 620.02 shall be used to chock the larger stones solidly in position and to substantially fill voids between the major stones as laid in the embankment. The exposed face of the rock mass shall be reasonably uniform, with no projections of more than 12 inches for derrick-placed embankment or 6 inches for hand-laid embankment, beyond the neat line shown on the plans or directed by the Engineer.

Backfill adjacent to the rock embankment shall consist of material from excavation items, compacted in accordance with Section 203.

Method of Measurement

620.04 The quantities to be paid for will be the number of cubic yards, measured in place, or tons, of special rock embankment of the kind shown by the bid schedule, furnished, placed, and accepted.

Basis of Payment

620.05 The quantities determined as provided above, will be paid for at the contract price per unit of measurement for each of the pay items listed below that appear in the bid schedule, which price and payment will be full compensation for the work of this section, except that excavation will be paid for as provided in Section 206 and backfill material will be paid for under the appropriate section.

621.01 This work shall consist of furnishing and installing corrugated metal spillway inlet assemblies and outlet pipes, and other appurtenances in accordance with these specifications,

and in reasonably close conformity with the design, grades and at the locations shown on the plans or as established by the Engineer.

Materials

621.02 Spillway inlet assemblies, outlets and connectors, shall be of the type and thicknesses shown on the plans, and shall be constructed of corrugated sheet metal conforming to the requirements of Section 603. The dimensions and proportions of inlet assemblies shall be in substantial agreement with those of the design shown on the plans, but minor variations may be accepted at the discretion of the Engineer to permit the use of manufacturer's standard jigs and templates in the fabriaction. Bulkheads and connections for outlet pipes shall be fillet-welded or riveted to the inlet chamber to form watertight joints. Anchors, lips, and skirts shall be securely riveted or welded.

Connections for outlet pipes shall be of the size shown on the plans and shall conform to the requirements of Section 603.

When called for in the bid schedule, spillway inlet assemblies and outlet pipes shall be bituminous coated or polymeric precoated conforming to the applicable coating requirements in Section 603.

Materials for the pipe anchor assemblies shall be as shown on the plans.

Construction Requirements

621.03 Spillway inlets shall be placed in the position shown on the plans and the earth backfill shall be consolidated by tamping.

Outlet pipes shall be installed in accordance with the requirements in Section 603. Care shall be used to prevent damage to the coatings during hauling and placing. All spots on the inlet assemblies or pipe where the coating has been damaged and all field rivet heads shall be repaired with two coats of an approved asphalt paint, or polymeric material.

Method of Measurement

621.04 The quantity of spillway assemblies to be paid for will be the number installed and accepted.

A spillway assembly shall consist of two end sections, two elbows, watertight connecting bands, pipe anchors, rock stilling basins and all other appurtenances necessary to complete the assembly as shown on the plans. The downdrain and outlet pipe will be measured and paid for under Section 603.

Excavation and backfill will not be paid for directly but will be subsidiary to other contract

items.

Basis of Payment

621.05 The quantities, determined as provided above, will be paid for at the contract price per unit of measurement, respectively, for each of the particular pay items listed below that is shown in the bid schedule, which prices and payment will be full compensation for the work prescribed in this section, except downdrains outlet pipes which will be paid for as provided in Section 603.

Pipe anchor assemblies will be paid for at the contract unit price per each complete in place.

622.01 This work shall consist of paving ditches, gutters, spillways, and other similar waterways with concrete, grouted rubble, mortared rubble, concrete and rubble, or a mixture of aggregate and bituminous material, constructed on a prepared bed in reasonably close conformity with these specifications and with the lines, grades, and dimensions shown on the plans or established by the Engineer.

If shown on the plans, the work shall include the construction of a bed course.

Materials

622.02 Materials shall meet the requirements specified in the following sections or subsections:

Materials and proportions for bituminous mixtures will be specified in the special provisions.

Rubble for pavement shall consist of approved, sound, durable stone of the sizes indicated on the plans. All stone will be inspected before and after laying, and all rejected material shall be removed immediately from the work.

Construction Requirements

622.03 Bed. The bed shall be formed at the required depth below and parallel with the finished surface of the waterway. All soft and yielding or other unsuitable material shall be removed and suitable material substituted. The bed shall be compacted and finished to a smooth, firm surface.

If shown on the plans, bed course material shall be placed and compacted to form a bed course of the required thickness.

622.04 Grouted Rubble. The pavement stones shall be bedded in the foundation with flat faces up and their longest dimensions at right angles to the center line of the waterway. Joints shall be broken and shall not exceed 1 inch in width.

The stones shall be rammed until the surface is firm and reasonably true to the finished surface in grade, alinement, and cross section. Any stone having an irregular or une ven surface shall be taken up and satisfactorily relaid.

After the stones have been rammed into place and the surface is satisfactory, the spaces or voids between and around the stones shall be filled with filler aggregate to within 4 inches of