854 – LANDSCAPE RETAINING WALL SYSTEM .
and galvanized in accordance with ASTM A 153.
inspection.
854.3CONSTRUCTION REQUIREMENTS
excavation for the wall with the underdrain construction so that drainage pipes will be constructed as specified. Maintain stable sides at all excavations by providi ng reasonable cut back slopes or shoring where necessary.
leveling pad for a width equal to or exceeding the length of the soil reinforcing (if used) plus 6 inches or to the limits shown in the Contract Documents. Compact the foundation prior to wall construction, with a smooth wheel vibratory roller with a minimum static weight of 8 tons to recompact any loose material the excavation process created to Type AA, MR 3-3 requireme nts. Remove and replace any foundatio n soils found to be unstable or unsatisfactory. Construct an unreinforced concrete or aggregate leveling pad at foundation level as shown in the Contract Documents. Cure the concrete pad for a minimum of 12 hours before placement of blocks.
erection of the next row. Should any modular blocks be out of tolerance, remove the fill and reset to their proper tolerances.
devices or by hand. Place blocks in successive horizontal lif ts in the sequence shown in the Contract Documents as backfill placement proceeds. Leave modular block unit cores void unless drainage fill material is specifically called for in the Contract Documents. Take care when placing material behind the blocks to prevent the blocks from moving outward. Vertical tolerances and horizontal alignment to lerance shall not exceed 1 ½ in ch when measured with a 10-foot straightedge. Offset each block from the block below it as sh own in the Contract Documents, with a maximum allowable offset of 1 inch. The maximum vertical overall tolerance of the wall is 1 inch per 10 feet of the wall height. Construct uniform horizontal and vertical joint openings between modular blocks a maximum of ⅛ inch thickness. Extend the Mesa Connector into adjoining courses with 2 Mesa standard connectors per unit. Place Anchor Lock Bar con tinuously only at elevations where geosyn thetic reinforcement is required. Place KeySystem I steel connection pins at soil re inforcing connection locati ons only and fiberglass alignment pins at all other pin locations.
level, roughly level backfill before placing and or attaching the reinforcement. Place reinforcing as shown in the Contract Documents, normal to the face of the wall. For ge osynthetic reinforcing, the end of the geogrid sheet shall terminate with a transverse element at the retained soil limi t to prevent curling of the sheet and aid in construction. Tightly draw the reinforcing against th e connections at the connect ors and stake the end of the geogrid sheet at the retained soil limit before backfilling is allowed, and main tain tautness during backfilling operations. Place backfill in maximum loose lift thickness of 10 inches or less as may be necessary to obtain the specified density. Compact the entire retained earth volume to 95% of maximum laboratory dry density at a moisture requirement of MR 3-3, SECTION 205 . For backfills containing more than 30% retained on the ¾ inch sieve, use a method compaction consisting of at least 4 passes of a heav y roller. Accomplish compaction without disturbance or displacement of reinforcing and facing. Begin compaction from the area nearest the wall face to the back of the reinforcing, except for a strip 3 feet wide adjacent to the backside of the facing. Compact this 3-foot strip with light mechanical tampers after compaction of the remainder of the layer. Soil density tests will not be required within this 3- foot area. 854 – LANDSCAPE RETAINING WALL SYSTEM
800-128At the end of each day’s operations, sh ape the last level of backfill to permit runoff of rainwater away from
the wall face. Remove and replace any wall materials that become damaged during backfill placement at the Contractor's expense. Trim excess geogrid protru ding from the face of the wall for MBWs to match the modular block’s face. Seal any geogrid permanently exposed fr om exposure to the elements with th e use of epoxy grout, grout or other methods as approved by the Engineer.
854.4MEASUREMENT AND PAYMENT
The Engineer will measure Landscape Retaining Wall by the square foot. The Engineer will use the neat lines shown in the Contract Documents to compute the quantities. Payment for "Landscape Retaining Wall" at the contract unit price is full compensation for the specified work.