ARCHIVED REPORTS_1994_1 - Laserfiche WebLink

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KLEINFELDER content of between 20 to 22 percent. If, for example, a work area measuring 400 x 50 feet was considered, a compacted thickness of 12 inches proposed, and for the laboratory maximum density of 120 per square foot (psf) (the actual in-place dry density would be approximately 95 percent of the standard), we calculate that 14 to 15 truckloads per section would be neede d to comply with the 20 percent Ione clay requirement. We note, however, that the actual spread calculations must be made during construction when equipment type is known and the moisture content of Ione clay confirmed. Due to the consequences of having the barrier layer fail the CIWMB and RWQCB regulations, it is important that the evaluation of the clay spread be conservative. In addition to the activities described above, the following specifications shall be followed during construction: (a) If the barrier layer is constructed in multiple lifts and is allowed to dry between lifts, the surface of each successive lift shall be scarified to a depth of two inches before the placement of the next loose lift. The purpose of the scarification is to improve bonding between successive lifts. (b) Equipment or truck traffic on the scarified surface shall not be permitted during the period between scarifying and the placement of the following lift. (c) Each lift shall be thoroughly compacted and satisfy moisture/density, and F'T permeability controls before a subsequent lift is placed. is (d) Compaction of lifts shall be performed with an appropriately heavy, properly ballasted, penetrating foot compactor CAT 815 (or equivalent, subject to approval by the Engineer). L (e) The daily work area shall extend a distance no greater than permits the maintenance of moist-soil conditions and construction operations. Desiccation and crusting of the lift surface shall be avoided as much as possible. (f) If desiccation and crusting of the lift surface occurs, the desiccated zone shall be removed and the exposed surface shall be scarified and moisture conditioned before remediation filling and compacting or subsequent filling and compaction is L permitted. CR9-42 Page 20 of 28 Copyright 1991 Kleinfelder, Inc.