**Construction Specification 795---Geotextile**

**1. Scope**

This work consists of furnishing all material, equipment, and labor
necessary for the installation of geotextiles.

**2. Quality**

Geotextiles shall conform to the requirements of Section 810,
Geotextiles, of the latest edition of the Alabama Department of
Transportation Standard Specifications for Highway Construction and
Section 6 of this specification.

**3. Storage**

Before use, the geotextile shall be stored in a clean, dry location out
of direct sunlight, not subject to extremes of either hot or cold
temperatures, and with the manufacturer\'s protective cover undisturbed.
Receiving, storage, and handling at the job site shall be in accordance
with the requirements listed in ASTM D 4873.

**4. Surface preparation**

The surface on which the geotextile is to be placed shall be graded to
the neat lines and grades as shown on the drawings. It shall be
reasonably smooth and free of loose rock and clods, holes, depressions,
projections, muddy conditions, and standing or flowing water (unless
otherwise specified in Section 7 of this specification).

**5. Placement**

Before the geotextile is placed, the soil surface will be reviewed for
quality assurance of the design and construction. The geotextile shall
be placed on the approved prepared surface at the locations and in
accordance with the details shown on the drawings and specified in
Section 7 of this specification. It shall be unrolled along the
placement area and loosely laid, without stretching, in such a manner
that it conforms to the surface irregularities when material or gabions
are placed on or against it. The geotextile may be folded and overlapped
to permit proper placement in designated area(s).

The geotextile shall be joined by overlapping a minimum of 18 inches
(unless otherwise specified) and secured against the underlying
foundation material. Securing pins, approved and provided by the
geotextile manufacturer, shall be placed along the edge of the panel or
roll material to adequately hold it in place during installation. Pins
shall be steel or fiberglass formed as a **U**, **L**, or **T** shape or
contain \"ears\" to prevent total penetration through the geotextile.
Steel washers shall be provided on all but the **U**-shaped pins. The
upstream or upslope geotextile shall overlap the abutting downslope
geotextile. At vertical laps, securing pins shall be inserted through
the bottom layers along a line through approximately the mid-point of
the overlap. At horizontal laps and across slope labs, securing shall be
inserted through the bottom layer only. Securing pins shall be placed
along a line about 2 inches in from the edge of the placed geotextile at
intervals not to exceed 12 feet unless otherwise specified. Additional
pins shall be installed as necessary and where appropriate to prevent
any undue slippage or movement of the geotextile. The use of securing
pins will be held to the minimum necessary. Pins are to remain in place
unless otherwise specified.

Should the geotextile be torn or punctured, or the overlaps or sewn
joint disturbed, as evidenced by visible geotextile damage, subgrade
pumping, intrusion, or grade distortion, the backfill around the damaged
or displaced area shall be removed and restored to the original approved
condition. The repair shall consist of a patch of the same type of
geotextile being used and overlaying the existing geotextile. When the
geotextile seams are required to be sewn, the overlay patch shall extend
a minimum of 1 foot beyond the edge of any damaged area and joined by
sewing as required for the original geotextile except that the sewing
shall be a minimum of 6 inches from the edge of the damaged geotextile.
Geotextile panels joined by overlap shall have the patch extend a
minimum of 2 feet from the edge of any damaged area.

The geotextile shall not be placed until it can be anchored and
protected with the specified covering within 48 hours or protected from
exposure to ultraviolet light. In no case shall material be dropped on
uncovered geotextile from a height of more than 3 feet.

**6. Measurement and payment**

***Method 1---***For items of work for which specific unit prices are
established in the contract, the quantity of geotextile for each type
placed within the specified limits is determined to the nearest
specified unit by measurements of the covered surfaces only,
disregarding that required for anchorage, seams, and overlaps. Payment
is made at the contract unit price. Such payment constitutes full
compensation for the completion of the work.

***Method 2---***For items of work for which specific unit prices are
established in the contract, the quantity of geotextile for each type
placed with the specified limits is determined to the nearest specified
unit by computing the area of the actual roll size or partial roll size
installed. The computed area will include the amount required for
overlap, seams, and anchorage as specified. Payment is made at the
contract unit price. Such payment constitutes full compensation for the
completion of the work.

***Method 3---***For items of work for which specific lump sum prices
are established in the contract, the quantity of geotextile is not
measured for payment. Payment for geotextiles is made at the contract
lump sum price and constitutes full compensation for the completion of
the work.

***All methods---***The following provisions apply to all methods of
measurement and payment. Compensation for any item of work described in
the contract, but not listed in the bid schedule, is included in the
payment for the item of work to which it is made subsidiary. Such items
and the items to which they are made subsidiary are identified in
Section 7 of this specification.

**7. Items of work and construction details**

Items of work to be constructed in conformance with these specifications
and the construction details therefor are:

[Bid Item 23, Geotextile]{.underline}

(1) This item shall consist of furnishing and installing the non-woven
    geotextile around the pipe joints, beneath the rock riprap and on
    the brush dam on the site as shown on the drawings. This item shall
    include the periodic removal and disposal of sediment accumulated
    upstream from the brush dam. Sediment will be removed before
    accumulated depth reaches one-half the height of the brush dams.

(2) The geotextile furnished for use beneath the rock riprap shall meet
    the requirements for Class A Erosion Control Geotextile from AASHTO
    M 288 and Section 810, Geotextiles, of the latest edition of the
    Alabama Department of Transportation Standard Specifications for
    Highway Construction. Geotextile shall be furnished in rolls not
    less than 12 ft. in width. Subgrade surfaces on which fabric is
    placed shall be reasonably smooth and free of rocks, clods, roots or
    other objects which could puncture or tear the fabric.

(3) The fabric beneath the riprap shall be placed with a minimum overlap
    of 24 inches and shall be secured in place as specified in Section
    5.

(4) The geotextile furnished for the brush dam shall meet the
    requirements for wire supported or self supported silt fences from
    AASHTO M 288 and Section 810, Geotextiles, of the latest edition of
    the Alabama Department of Transportation Standard Specifications for
    Highway Construction. The geotextile shall be furnished in rolls not
    less than 12 ft. in width. Fabric shall be draped over the upstream
    face of the brush dams and tied or nailed at the top edge
    sufficiently to keep the fabric in place.

(5) Fabric shall be installed on the upstream side of the brush dam with
    the bottom edge buried about 12 in. into the ground to prevent blow
    out underneath the fabric. The brush dam and fabric shall be
    installed prior to any other land disturbance activities.

(6) Remove and dispose of sediment accumulated on the upstream side of
    the brush dam prior to vegetating the site.

(7) The geotextile will be left in place on the brush dam after
    construction has been completed.

(8) Measurement and payment will be by Method