Laserfiche WebLink
'DRAFT <br /> The rockery rocks should be tabular and rectangular. Rocks should be hard,sound,durable <br /> and free of weathered porcions, seams, cracks and other defects. The rock density should not be <br /> less than 160 pounds per cubic foot. The lower 4 w 6 feet of the rockery should be conswaed <br /> using 4- co 5-man size rocks as defined by Associated Rockery Convactors. <br /> Rock selection and placement should be accomplished to reduce the number and size of <br /> voids. In the ezposed face of the wall, no openings greater than 6 inches in dimension in any <br /> direction ahould be permitted.Rock courses should be gradational in size from bottom to top with <br /> the lazgest rocks of uniform size being placed for the lowest double course. The contact between <br /> rocks should slope downwazd to ihe bacic side of the rockery. Each course of rocks should be <br /> seated tighdy and evenly on the course beneath. After seating each course of rock,voids betwecn <br /> the rocks should be chinked on the back with quarry spalls to eliminate pusage of bacidll <br /> material, Backfill immediately behind the rockery should also consist of quazry spalis. 'Ilie <br /> spalis should wnsist of well-graded 3/4 tu 4-inch crushed rock and should be durable, <br /> uncontaminated by soil or other debris, and not readily susceptible to weathering. <br /> 7tie quarry spall fill should be placed to a width of not less than 18 inches between the <br /> rockery and the face of tf�e cut. 'I1�e spalls should be placed and compacted in lifu to a level <br /> approximately 2 inches below the top of each course of rocks as they are placed, until the <br /> uppermost course is placed. Any bacldli material falling onto the bearing surface of one rock <br /> course must be removed before setting the next course. Rock placement should be such that each <br /> rock above the base caurse will be supported on two rocks in the next lower row. <br /> A perforated drainpipe should be embedded in the baddll at the bue of the rockery. This <br /> drain should dischazge to the storm drain aystem or daylight at a location which will not impact <br /> the adjaceat stecp slopes or other moisture-sensitive areas. <br /> Rockeries in Ftll Embankments: Rockeries essentially serve as protection against erosion <br /> and minor sioughing along existiog stable slopes and provide linle "retaining' support. For this <br /> reason, if a rockery is selected for placement against a fill embankment, we recommend <br /> reinforcing the fill beh(nd the rock face. We recommend that the fill immediately behind the <br /> rockery be reinforced with Tensar SR-1 or SR-2 geogrid. We will provide detailed reinforcement <br /> recommendatioas if a reinforced rockery is selected for final design. <br /> T'he construttion guidelines presented in the previous section aze also applicable to rockeries <br /> constiuctad in fill embankments. Rockeries should be installed by a qualified contractor <br /> ezperienced in rockery construction. We recommend that construction of the rockery be <br /> monitored by a representative of our firm. <br /> I.�ystone Retaining iNalls <br /> Keyatone Retaining Wall systems are a proprietary product that consist of precast key- <br /> shaped concrete modules and interlocking fiberglazs pins. Geogrid reinforcing suips are placed <br /> in the fill behind the blocks and a granutar base is recommended immediately behind the block <br /> face for drainage. The a�alis are easily erected and provide a low-cost, aesthetically pleasing <br /> G e o E n p i n e e r � 9 FJ<No.0120.1S4R10/062292 <br />