853 – RETAINING WALL SYSTEM each day's operations, shape 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 from exposure to the elements with the use of epoxy grout, grout, or other methods as approved by the Engineer. No construction traffic is permitted on galvanized steel reinforcing. Use only rubber tired vehicles going less than 5 mph with no turning on geosynthetic reinforcement.
853.4MEASUREMENT AND PAYMENT
The Engineer will measure Retaining Wall by the squa re foot. The Engineer will use the neat lines shown in the Contract Documents to compute the quantities. Payment for "Retaining Wall (*)" at the contract un it price is full compensation for the specified work.
854 – LANDSCAPE RETAINING WALL SYSTEM
800-125SECTION 854
LANDSCAPE R ETAINING WALL SYSTEM
854.1DESCRIPTION
Landscape retaining walls as defined by KDOT consist of systems meeting all of the following requirements: a total height less than 6 feet measured from top of footing to top of wall cap at the highest point; the maximum live load surcharge of 100 pound per square foot; the backslope is level; is not a multiple tiered wall; and is not a critical structure whose failure would cause loss of life, serious loss of function or access to adjacent necessary serv ices/structures, or result in significant property damage.
For systems meeting these criteria, National Concrete Masonry Association Design Standards for Segmental Retaining Walls may be utilized. The scope of work for wall erection includes; excavation, grading and compaction of the wall foundation, general and local de watering as required for proper execution of the work, construction of leveling pads, erection of modular block wall (MBW) elements, placement of soil reinforcing and placement and compaction of select backfill material as required. The scope of work also includes providing a nd placing cast-in-place concrete coping, if specified. Include in the wall foundation all area underlying the le veling pad and the reinforced soil volume.
B I D I T E M U N I T S Landscape Retaining Wall Square Foot
854.2MATERIALS
reinforcing, MBW and all necessary accessories) from an approved manufacturer according to the acceptable alternates for each particular structure as listed in the Contract Documents. The Bureau of Materials and Research will maintain a list of approved systems. Products will remain on the prequalified list as long as Field Performance is satisfactory. Prequalification is attained upon submittal of a HITEC review and successfully addressing all issues and concerns raised by the HITEC review and KDOT. Alternately, the Mechanically Stabilized Earth supplier provides documentation in accordance with Section 8.2 of the Federal Highway Administration Publication titled “Mechanically Stabilized Earth Walls and Reinforced Soil Slopes Design and Construction Guidelines”, publication number FHWA-N HI-00-043, and then subsequently addresses all issues and concerns raised by KDOT.
compressive strength at 28 days of 4000 psi. Retarding admixtures may be used with prior approval of the Engineer. Accelerating agents or any admixture containing chlorides are prohibited. Provide the MBW elements with a maximum abso rption rate of 5% by weight and a minimum face shell thickness of 2 inch and complies with ASTM C 1372.
Sampling and Testing Concrete Masonry Units, except as noted elsewhere in this specification. The MBW will be considered acceptable, regardless of curing age, if co mpression test results comply with the 28-day strength specifications, and if the visual inspection is satisfactorily completed. Provi de facilities and perform all necessary sampling and testing. The Engineer may observe sampling and testing. Give notice a minimum of 1 week in advance of sampling and testing.
Association.
Any production lot which does not comply with subsection 854.2b.(2) , Compressive Strength, will be rejected.
854 – LANDSCAPE RETAINING WALL SYSTEM 800-126 (6) Finish. Finish the MBW as specified in the Cont ract Documents. Screed the non-exposed faces of the 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.