Category:720 Mechanically Stabilized Earth Wall Systems

720.1 Materials Guidance for Sec 720

This guidance establishes procedures for inspection and reporting of small and large block mechanically stabilized earth (MSE) wall systems. Inspection of these items covers aggregate, geotextiles, blocks, face panels, reinforcing grids, and other miscellaneous hardware necessary as show on the wall system drawings.

720.1.1 Apparatus

None

720.1.2 Procedure

Sec 720 requires the contractor to deliver six copies of the MSE wall design plans. At least one of these copies should be forwarded to District Materials personnel.

The design of MSE wall systems must be approved by Bridge Division prior to construction. A listing of approved designs is maintained. If the design has not already been approved by Bridge Division, it must be submitted to Bridge and gain approval before construction can begin.

720.1.2.1 Contract Sampling and Testing Requirements

Once District Materials has received a copy of the MSE wall plans, they should edit the Contract Sampling and Testing Requirements accordingly. Since MSE wall designs vary greatly, care should be given as to what components and quantities are required. At a minimum, there should exist a requirement for reporting the entire approved wall system. Also, since the granular backfill plays a crucial role in supporting the structure, there should be a requirement for the acceptance of this material.

720.1.2.2 Certifications

Certifications should be received and checked for conformance to the various portions of Secs 720, 1052, 1011 and others necessary. The project office shall keep these certifications as part of the project files.

720.1.3 Reports

Due to the variance of designs, several AASHTOWARE Project (AWP) records may be required to correctly report acceptance of a MSE wall system and its components.

720.1.3.1 Completed Wall System

The acceptance of constructed wall system sections built to the approved design should be reported by Construction personnel using the 0720MSEW material code.

720.1.3.2 Granular Backfill

The certification for this material should be reviewed and a sample record made for acceptance. Any testing done to verify the certification will be reported using AWP.

720.1.3.3 Miscellaneous Components

Various material codes exist for reporting the components used in MSE walls. Most of these components are accepted by certification as outlined in Sec 1052. Consult the Sampling Checklist regarding reporting requirements for your specific project.