719TILE DRAINS

719.01Description

This work shall consist of the installation of drain tile in accordance with 105.03.

MATERIALS

719.02Materials

Materials shall be in acco rdance with the following:

Reinforcing Bars .......................................................... 910.01 Riprap .......................................................................... 616.02 Rodent Screen .............................................................. 718.02

Drain tile materials shall be in accordance with 715.02(d). Drain tile terminal pipe shall be underdrain outlet pipe in accordance with 715.02(i).

CONSTRUCTION REQUIREMENTS

719.03Trench Excavation

The trench excavation shall begin at the outlet end and proceed towards the upper end, true to the required line and grade. The trench shall be as shown on the plans. If no trench details are shown on the pans, the trench shall be of sufficient width to provide ample working space on each side of the drain tile to enable compaction of the backfill around the tile. Recesses shall be cut into the trench bottom to accommodate any projecting hubs or bells.

If excavation is made too deep, proper b earing shall be secured by backfilling to the required elevation with sand, clay, or other approved material which shall be tamped into place and shaped properly.

If a firm foundation is not encountered at the required trench bottom grade, the unstable material shall be removed to a depth that provides ample support after being backfilled, compacted, and shaped to the required elevation or the drain tile shall be 719.01

laid on composite planking which is not less than 1 in. thick, 10 in. wide, and 10 ft long.

If rock is encountered at or above the required trench bottom grade, the trench shall be excavated at least 8 in. below the pipe and backfilled, compacted, and shaped as described above.

Where excavation is made for installing drain tile across private property, the topsoil and sod, if present, shall be kept in separate stockpiles. After completion of the backfill operation, the topsoil and sod shall be placed so that the area is restored as closely as possible to its original condition.

719.04Laying Tile 50

Tile shall not be laid on a frozen or muddy trench bottom. It shall be laid true to line and grade, starting at the outlet end. Each tile shall have a firm bearing for its entire length and joints left as tight as practicable by turning the individual sections until the ends fit closely. A joint which does not close to within 1/4 in. shall be covered with pieces of broken tile. If laid on composite planking, the joints shall be covered with pieces of broken tile and then entirely covered with clay and tamped.

Drain tile installed on private property shall be perforated pipe in accordance with

715.02(d)

When an existing tile drain is encountered on permanent right-of-way, it shall be replaced in the following manner. If the tile is intercepted by a side ditch prior to crossing proposed pavement, it shall be replaced between the right-of-way line and the ditch with non-perforated drain tile and a 10-fo ot long terminal pipe section of drain tile with a rodent screen. If the tile is to outlet into a storm sewer, it shall be replaced between the right-of-way line and the st orm sewer with pipe in accordance with

(b). If the tile is to outlet at a side ditch after crossing the proposed pavement,

it shall be replaced between the right-of-way line and the ditch with pipe in accordance with 715.02(a) with a rodent screen. If the tile is to be maintained across the right-of- way, it shall be replaced from right-of-way line to right-of-way line with pipe in 70 accordance with 715.02(a).

719.05Backfilling

Pipe which replaces drain tile shall be backfilled in accordance with 715.09.

719.06Blank

719.07Method of Measurement

Drain tile and replacement pipe of the type and size specified will be measured in accordance with 715.13. Terminating pipe sections of the type and size specified will 80 be measured per linear foot. Structure backfill will be measured in accordance with

211.09. Flowable backfill will be measured in accordance with 213.08. Riprap will be

measured in accordance with 616.12. 719.07

Tee or wye branch connections will be measured per each along the centerline of the barrel. An additional allowance of 5 lft of the smaller diameter pipe will be made for making such connections.

Elbow connections will be measured along the centerline of such connection. An additional allowance of 2 lft of pipe of the same diameter as that of the elbow will be 90 made for each such connection.

Increaser and reducer connections will be measured by the linear foot as the larger diameter pipe over the length of the connection.

719.08Basis of Payment

The accepted quantities of drain tile and replacement pipe will be paid for in accordance with 715.14. Terminating pipe sections will be paid for at the contract unit price per linear foot for pipe, drain tile terminal section, of the size specified, complete in place. Structure backfill will be paid for in accordance with 211.10. Flowable 100 backfill will be paid for in accordance with 213.09. Riprap will be paid for in accordance with 616.13.

Tee and wye connections will be paid for by means of the allowance of an additional 5 lft of the smaller pipe at the connection. Elbow connections will be paid for by means of the allowance of an additional 2 lft of the pipe at the connection.

If increaser or reducer connections are made, payment will be made on the basis of the larger diameter of the connection for the full length of the section forming such connections. 110

Payment will be made under:

Pay Item Pay Unit Symbol

Pipe, Drain Tile Terminal Section, ______ in. .......................... LFT diameter

The cost of excavating, backfilling with suitable excavated material, disposal, planking, removal of existing tile, and neces sary incidentals shall be included in the 120 cost of this work.

719.08