854 – LANDSCAPE RETAINING WALL SYSTEM
MBW to eliminate open pockets of aggregate and surface distortions in excess of ¼ inch.
MBW: Manufacture all units within 1/8 inch of the plan dimension and connection slots within 3/16 inch of plan dimension. Provide MBW units with a minimum of: 0.83 square feet of f ace area each for full units. 0.5 square feet of face area for each cap unit.
Provide a MBW system with angled sides capable of concave or convex alignm ent curves with minimum radius of 4 ½ to 6 feet.
on a production lot basis as specified in ASTM C 140.
following defects: Defects that indicate imperfect molding Honeycombed or open texture concrete surfaces Any damage that would prevent making a satisfactory joint Chipped facing panel/unit edges Discolored panels or blocks beyond reasonable variances in the opinion of the Engineer.
stored at the casting plant in a manner acceptable to the Engineer.
danger of staining, chipping, cracks, fractures and excessive bending stresses. Support blocks in storage on firm foundations in a manner that will protect the exposed exterior finish. (12) Basis of Acceptance. The Re taining Wall System will be accepted on the basis of satisfactory results of materials test, compliance with dimensional requirements and visual inspection at the point of usage
stone listed in TABLE 1107-6 , or SB-1 or SB-2 in TABLE 1107-1 , if required.
Leveling pads. Commercial Grade (AE) concrete complying with SECTIONS 401, 402 and 1102 . Cast-in-Place copings. Grade 4.0 (AE) concrete complying with SECTIONS 401, 402 and 1102 .
with the minimum requirements of ASTM A82 and weld into the finished me sh fabric in accordance with ASTM A185. Form loops or weld connection plates so the variati on in length between the longest and the shortest longitudinal wire in a reinforcing mesh panel is no more than ⅛ inch when measured from the cr oss-wire nearest the end of the reinforcing mesh panel. Loop fabricati on must permit a 5/8 inch diameter rod to pass through all loops on each piece of mesh. Galvanize reinforcing mesh in accordance with ASTM A123M. The me sh will be accepted on the basis of a Type A Certification and visual inspection.
ultraviolet and heat degradation. The geogrid material will be listed on the approved list for Geogrid Mechanically Stabilized Embankment/Earth Slopes on Firm Foundations, and accordin g to the Contract Documents.
polyvinyl chloride to maintain the integrity of the geosynthetic during handling and placement and to protect it during construction. The geosynthetic material will be listed on the approved list for Geogrid Mechanically Stabilized Embankment/Earth Slopes on Firm Foundations, and accordin g to the Contract Documents.
854 – LANDSCAPE RETAINING WALL SYSTEM 800-127 g. Attachment Devices.
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.