607EARTH RETAINING WALL SYSTEMS

607.1Description.

This work consists of designing, fabricating, providing, and placing MSE walls and modular block retaining walls.

607.2Materials.

607.3Construction.

607.3.1 Submittals.

and the specified edition of the AASHTO LRFD Bridge Design Specifications. The engineer will take responsibility for external stability. The wall system designer shall take responsibility for all other limit states in the design for the selected wall system.

105.4, before beginning fabrication. Have a registered State of Delaware professional engineer seal the calculations and drawings and obtain the engineer’s approval before fabrication. Include the following information in the submittal:

the system.

involving construction wholly or partially in original ground or at locations specified in the contract.

in the contract.

including complete material specifications.

comply with the applicable contract specifications. Provide the engineer with a copy of all test results performed by the contractor or his supplier necessary to assure contract compliance.

607.3.2 Excavation and Backfill.

area remains dry in accordance with Section 906.

as required for the retaining wall system.

any foundation soils found unsuitable, as directed by the engineer.

elevation as the MSE wall backfill placement, meeting density requirements in accordance with the contract. 607.3.3 Leveling pad.

contract. Cure the leveling pad a minimum of 12-hours with materials in accordance with Section 1022.6 before placement of wall panels. The concrete finish will contain a smooth and flat surface, and not vary from the design elevation, as shown in the contract.

accordance with the manufacturer’s instructions. 607.3.4 Wall erection.

lifting devices set into the upper edge of the panels and place in successive horizontal lifts in the sequence shown on the working drawings as backfill placement proceeds. When placing backfill material behind the panels, maintain the panels in vertical position by means of temporary wooden wedges placed in the joint at the junction of the 2 adjacent panels on the external side of the wall. Use external bracing for the initial lift.

inch when measured along a 10-foot straight edge.

of wall height.

or more than 1 1/4- inches.

joint. Ensure that the fabric extends a minimum of 9-inches onto each panel.

soil. Place reinforcing mesh or strips perpendicular to the wall, unless otherwise shown in the contract or as directed by the engineer.

where the design calls for a poured concrete coping or parapet.

607.3.5 Backfill Placement.

first 3-feet perpendicular to the back face of the panel for the full height of the wall.

compaction throughout each layer. Remove backfill material with moisture content outside the acceptable range and rework until the moisture content is uniformly acceptable throughout the entire lift.

mechanical tamper or hand tamp. Do not use a vibratory system within this area.

rapidly direct runoff of rainwater away from the wall. In addition, do not allow surface runoff from adjacent areas to enter the wall construction site.

manufacturer’s instructions.

607.4Method of Measurement.

placed and accepted. The Department will take the vertical measurement from the top of the leveling pad to the bottom of the coping.

material.

masonry unit modular block retaining walls as the number of square feet of wall placed and accepted. The Department will take the vertical measurement from the top of the leveling pad or footer.

607.5Basis of Payment.

providing the design, providing and placing all materials including backfill, and performing all work required in accordance with the contract and approved design.

providing all materials, and performing all work required to construct the wall system as specified.

ITEM DESCRIPTION UNIT 607000 MECHANICALLY STABILIZED EARTH WALLS SF 607001 MECHANICALLY STABILIZED EARTH WALLS LS 607011 ARCHITECTURAL SEGMENTAL RETAINING WALLS SF

ITEM DESCRIPTION UNIT 607012 CONCRETE MASONRY UNIT MODULAR BLOCK RETAINING WALLS SF