859 SECTION 735 – TEMPORARY WIRE-FACED MECHANICALLY STABILIZED EARTH RETAINING WALLS
735.01 Description This work shall consist of the design, furnishing materials, and placement of temporary wire-faced mechanically stabilized earth retaining walls in accordance with
105.03.
735.02 General Desi gn Requirements
A temporary wire-faced MSE wall shall c onsist of wire-facing elements, ground 10 reinforcement elements mechanically connect ed to the wire-facing elements, and a drainage system if required. Concrete face panels will be required for the lower course of the wall if shown on the plans. Ground reinforcement shall have sufficient strength, frictional resistance, and quantity as required by the design. A temporary wire-faced MSE wall shall be constructed in accordance with the approved plans and panels working drawings based on the requirements herein. The recommendations of the wall system supplier shall meet or exceed the minimum performance requirements included herein. 20 If appurtenances interfere with connecting ground reinforcement to face panels, back up panels shall be provided. The top of the wire-facing elements shall be at or above the top of the wall envelope shown on the plans. The maximum dimensions for wire-face panels shall be limited to 2 ft vertical and 8 ft horizontal. 735.03 Design Criteria 30 The design life of the wall shall be 36 months. The minimum allowable yield stress for reinforcement shall be 65 ksi. The maximum allowable stress in the reduced section after sacrificial steel has been removed at the end of the design life shall be 0.55Fy for WWR. The maximum allowable stress may be increased to 0.77Fy if the design life does not exceed 36 months. The reduced section of ground reinforcement shall be limited to the allowable stress shown above at the end of the 36-month design life. The connections of the ground-reinforcing steel to the wire-facing shall not be more than 24 in. apart vertically. 40 The design shall otherwise be in accordance with 731.02 and 731.03.
735.04 Submittals The Contractor shall submit working drawings in accordance with 105.02. The Contractor shall submit design calculations in accordance with 105.02 and the 735.04
860 following additional requirements. In case of discrepancy, the requirements listed below supersede those listed in 105.02. Design calculations shall show the complete design of the temporary wire-faced wall. Calc ulations may be in either longhand or computer-printout format and shall follow a systematic and logical methodology. A 50 summary sheet that shows design assumptions and their source, controlling parameters and load cases, and other pertinent input and output information shall be attached to the calculations package. Wall construction operations shall not begin until the Contractor receives written notice that the working drawings are approved.
a.The working drawings shall include all details, dimensions, quantities, and cross-sections necessary to construct the wall. They shall include, but not be limited to the requirements listed in 731.04(a) and (b).
b.Wire-facing details shall show all dimensions necessary to construct the element, all wire in the element, and the location of ground-reinforcing-system devices at tached to the wire-facing. MATERIALS
735.05 Materials
Materials shall be in acco rdance with the following: Admixtures for Use in Concrete .................................. 912.03 70 Air-Cooled Blast-Furnace Slag ................................... 901.09 Alignment Pins ............................................................ 910.07(d) B Borrow ..................................................................... 211.02 Coarse Aggregate, Class A or Higher, Size No. 8 or No. 91 ............................................ 904.03 Components of MSE Re taining Walls ......................... 901.10 Concrete, Class A ........................................................ 702 Fine Aggregate, Size No. 23 ........................................ 904.02 Fly Ash ........................................................................ 901.02 Geotextile for Underdrains .......................................... 918.02 80 Joint Spacers and Joint Covering ................................. 901.10(b) PCC Components ........................................................ 901.10 Portland Ceme nt .......................................................... 901.01(b) Rapid Setting Patch Materials ..................................... 901.07 Reinforci ng Bars .......................................................... 910.01 Steel Components ........................................................ 910.07 Steel WWR, Sm ooth ................................................... 910.01(b)5 Water ........................................................................... 913.01 Backfill material used in the tempor ary wire-faced MSE wall volume shall be 90 Type 3 structure backfill in accordance with 211 with the exception that nominal size aggregate No. 30 shall not be used. 735.05 All retention fabric or filter cloth shal l be geotextile for use with underdrains. The Contractor shall supply the MSE retaining wall components described above, including wire-facing, concrete face panels, retaining strips or mesh, tie strips, fasteners, earth-retention materials, draina ge system components, and all necessary incidentals, through a manufacturer listed on the QPL of Retaining Wall Systems. 100 CONSTRUCTION REQUIREMENTS
735.06 General Requirements Foundation preparation shall be in acco rdance with 731.07. Retaining-wall
excavation shall be in accordance with 731.08.
735.07 Wall Erection
The wall system components shall be constructed in accordance with the wall system supplier’s recommendations and construction manual. 110 The Contractor shall perform the necessary work to verify that the foundation is at the correct elevation, that the wall is constructed to the correct alignment, and that the work is in accordance wi th the specified tolerances. Ground reinforcement shall be placed no rmal to the face of the wall, unless otherwise shown on the plans or as directed. Prior to placement of the ground reinforcement, backfill shall be placed and compacted in accordance with 731.11. Where shown on the plans, backing mats shall be placed behind the wire-facing. 120 Where shown on the plans, galvanized screens with openings not exceeding 1/2 in. shall be placed behind the wi re-facing to retain the earth.
735.08 Method of Measurement
The measurement of temporary wire-facing and temporary wall erection will be based on the square foot of area contained within the neat line limits of the wall envelope shown on the plans and not that of the wall system supplier. Common excavation will be measured in accordance with 203.27. Structure backfill and B borrow will be measur ed in accordance with 211.09. 130 Unsuitable foundation materials, if found, will be measured in accordance with
211.09 If unsuitable foundation material is encountered in the portion of the foundation beneath the reinforced backfill zone in a section constructed on original
ground or in a cut section, the removal, replacement, and compaction of the new material will be measured in accordance with 203.27 and 211.09. 735.08 862 Geotextile materials will not be measured. Drainage of the backfill including piping, aggregates, and incidentals will not be measured.
735.09 Basis of Payment
The accepted quantities of temporary wire-facing and temporary wall erection will be paid for at the contract unit price per square foot. Common excavation will be paid for in accordance with 203.28. Structure backfill and B borrow will be paid for in accordance with 211.10. Unsuitable foundation materials will be paid for in accordance with 211.10. Payment will be made under: 150 Pay Item Pay Unit Symbol Temporary Wall Erection .......................................................... SFT Temporary Wire-Facing ............................................................ SFT The cost of all MSE retaining wall components including wire-facing elements, concrete face panels, ground reinforcing, tie strips, fasteners, soil retention materials, repair or replacement of wire-facing elemen ts damaged or removed due to backfill placement, and incidentals shall be include d in the cost of temporary wire-facing. If unsuitable foundation material is encountered in the portion of the foundation beneath the reinforced backfill zone in a section constructed on original ground or in a cut section, the cost of removal, replacement, and compaction of new material will be paid for in accordance with 203.28 and 211.10. If unsuitable foundation material is encountered in the portion of the foundation beneath the reinforced backfill zone that is constructed on an embankment section that is constructed under the same contract, the cost of removal, replacement, and compaction of new material will not be considered for payment. The cost of geotextiles shall be included in the cost of the pay items in this section. The cost of all labor and materials required to prepare the wall foundation, to place the ground reinforcement, and to erect the c oncrete face panels shall be included in the cost of temporary wall erection. The cost of labor and materials required to provide for the drainage of the backfill including piping, aggregates, or geotextile materials shall be included in the cost of temporary wire-facing. The cost of performing the laboratory tests by a qualified geotechnical consultant for structure backfill or ACBF slag shall be included in the cost of the pay items in this section. 735.09 The cost of all labor and materials for geotextile materials used shall be included in the cost of the pay items in this section. The cost of cutting, altering, and recoating of the ground reinforcement at the site shall be included in the cost of temporary wall erection. 190
Source: Indiana Standard Specifications, 2024 Edition. Pages 9–13 of 1,248.