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4. Each gabion basket or mattress shall be anchored with soil anchor <br />stakes of sufficient length to adequately hold the gabion to the slope <br />shown on the plans. The gabion shall be fastened to the anchor staked <br />• with a tie wire. The Contractor shall determine for himself whether <br />the holes for the soil anchor stakes are to be drilled or whether the <br />stakes may be driven. Care shall be taken to avoid drilling holes to a <br />greater depth than is necessary to place the top of the finished stake <br />slightly above the top of the finished gabion. <br />5. The field connections between adjacent wire baskets shall be made as <br />recommended by the manufacturer and shall develop a connection <br />strong enough that the failure under test shall occur in the mesh <br />rather than in the lacing. <br />D. Plastic Filter Fabric <br />A plastic filter cloth shall be placed under riprap as specified. The surface <br />to receive the cloth shall be prepared to a relatively smooth condition free <br />- of obstructions, depressions and debris. The cloth shall not be laid in a <br />stretched condition, but shall be laid loosely with the long dimension <br />perpendicular to the channel centerline. The panels shall be overlapped a <br />_ minimum of 8 inches with securing pins inserted through both layers at not <br />greater than 6 foot intervals along a line through the approximate midpoint <br />of the overlap. The cloth shall be placed so that the upstream panel will <br />overlap the downstream panel. Securing pins shall be placed along a line <br />approximately 2 inches in from the edge of the outer limits of the completed <br />_ filter cloth area at intervals not greater than 6 feet unless otherwise shown <br />on the Drawings. Additional pins shall be installed es necessary to prevent <br />• any slippage of the filter cloth, regardless of location. Each securing pin <br />shall be inserted through the cloth until the washer bears against the cloth <br />" and secures it firmly to the foundation. No more than 2 horizontal overlaps <br />shall be permitted. Vertical overlaps shall be staggered a minimum of 5 <br />feet. Stone shall not be dropped on the cloth from a height greater than 2 <br />- feet. <br />Filter cloths can be placed subaqueously by using steel rods as weights <br />fastened along the edges. Additional intermediate weights can be used to <br />assist sinking the cloth into place. <br />Plastic filter cloth damaged or displaced before or during installation or <br />during placement of overlying layers of stone shall be replaced or repaired <br />to the satisfaction of the Engineer at the Contractor's expense. <br />Filter fabric underlaying riprap, gabions and toe drain rock shall extend up <br />the sides to within 6 inches of the finished surface and anchor for at least 12 <br />inches into the surrounding soil. <br />E. Granular Filter Blanket <br />The filter blanket shall be placed on the prepared slope or area to the full <br />specified thickness of each specified layer in one operation, using methods <br />which will not cause segregation of particle sizes within the bedding. The <br />surface of the finish layers should be reasonably even and free from mounds <br />• and windows. Additional layers of filter material, when required, shall be <br />placed in the same manner, using methods which w~11 not cause mixture of <br />the material in the different layers. <br />02540-9 <br />