Laserfiche WebLink
<br />3.'7 - Filter Blanket <br /> <br />All material cOlllprising the filter blanket should be tough, durable <br />particles reasonably free from thin, flat, and elongated pieces and should <br />contain no organic matter nor soft, friable particles. The gradation of <br />lllaterial in each layer of the blanket is determined as explained in sec- <br />tion 2.7. <br /> <br />. <br /> <br />IV - COlfSTRUCTION <br /> <br />~ <br /> <br />Inspection by the engineer during all phases of construction is <br />essential to ensure proper placement at the protective cover. <br /> <br />: <br /> <br />4.1 - Areas to be Protected <br /> <br />Brush, trees, stumps, and other objectionable material should be <br />removed from slopes and other areas to be protected by riprap, and the <br />areas should be dressed to a smooth surtace. All soft or spongy material <br />should be removed to the depth determined by the soils engineer and <br />replaced with sui table material. Filled areas should be compacted as for <br />embankments. Sand slopes protected by riprap should be no steeper than 2: 1. <br />The toe trench, when specified (see section 2.1.2), should be dug and main- <br />tained until the riprap is placed. The filter blanket should be placed on . <br />the prepared slope or on the area to be provided with foundation protection <br />as discussed in section 4.8. Protection tor structure foundations should <br />be provided as early as the foundation construction permits. <br /> <br />4.2 - Dumped Riprap <br /> <br />Stone for riprap should be placed on the til ter blanket or, when the <br />fU ter blanket is not required, directly on the prepared slope or area in <br />a manner which will produce a reasonably well-graded mass of stone with the <br />minimum practicable percentage of voids. The entire mass ot stone should <br />be placed in contormance with the lines, grades, and thicknesses shown on <br />the plans. The riprap should be placed to its full course thickness at one <br />operation and in such a manner as to avoid displacing the underlying mate- <br />rial. Placing riprap in layers or by dumping into chutes and similar <br />methods likely to cause segregation should not be permitted. <br /> <br />. <br /> <br />: <br /> <br />The larger stones should be well distributed and the entire mass of <br />stone should conform approximately to the gradation specitied in section <br />3.1.1 The riprap should be so placed and distributed that there will be no <br />large accumulations of either the larger or smaller sizes of stone. <br /> <br />11-24 <br /> <br />. <br />