SPECIFICATION 802

MECHANICALLY STABILISED EARTH WALLS

Copyright MAIN ROADS Western Australia

Specification 802Mechanically Stabilised Earth Walls – 04/10129 Issued 20/04/2017
REVISION REGISTER
Clause
Number / Description of Revision / Authorised By / Issue Date
Whole document / Reformatted / SCO / 20/04/2017
802.06 / URL to the list of approved RSW Systems amended / SDSE / 07/08/2015
802.06 / URL to the list of approved RSW Systems shown / A/SDSE / 25/06/2013
802.08 / Electrochemical Properties of Reinforced Fill Materials included / SDSE / 24/02/2010
Whole Document / Specification reviewed by Custodian, no changes made / SDSE / 17/08/2009
Minor formatting and updated Revision date in Footer to reflect document reviewed / SCO/A
802.06 / Accept use of polymeric reinforcing straps / SDSE / 13/12/2006
Whole document / Complete revision of Issue 1.1 to new format / MCP / 01/08/2006

CONTENTS

ClausePage No

GENERAL

802.01Scope

802.02References

802.03 – 802.05NOT USED

PRODUCTS AND MATERIALS

802.06Component Materials

802.07Cement Stabilised Layer

802.08Electrochemical Properties of Reinforced Fill Materials (Backfill)

802.09 – 802.25NOT USED

DESIGN

802.26General

802.27Tender Submission

802.28Full Design Documentation

802.29 – 802.40NOT USED

INSTALLATION

802.41Commencement

802.42Installation

802.43 – 802.80NOT USED

AS BUILT AND HANDOVER REQUIREMENTS

802.81 – 802.90NOT USED

CONTRACT SPECIFIC REQUIREMENTS

802.91 – 802.99NOT USED

ANNEXURE 802A

Borehole Information

SPECIFICATION 802

MECHANICALLY STABILISED EARTH WALLS

GENERAL
802.01SCOPE
  1. The work to be executed under this specification consists of the design, manufacture and construction of Mechanically Stabilised Earth (MSE) Walls (Reinforced Earth Walls) for use in bridge abutments and associated retaining walls.

802.02REFERENCES
  1. Australian Standards, MAIN ROADS Western Australia Standards and MAIN ROADS Western Australia Test Methods are referred to in abbreviated form (e.g. AS 1234, MRS 67-08-43 or WA 123). For convenience, the full titles are given below:

Australian Standards
AS 1289.6.3.3Methods of Testing Soils for Engineering Purposes - Soil Strength and Consolidation Tests - Determination of the Penetration Resistance of a Soil - Perth Sand Penetrometer Test
AS 4678Earth-retaining Structures
AS 5100Bridge Design
Main Roads Specifications
Specification 201QUALITY SYSTEMS
Specification 406ROCK PROTECTION
Specification 801EXCAVATION AND BACKFILL FOR STRUCTURES
802.03 – 802.05NOT USED
PRODUCTS AND MATERIALS
802.06COMPONENT MATERIALS
  1. Only MSE systems composed of precast concrete facing panels shall be considered for acceptance.
/ Facing Panels
  1. All metallic reinforcing strips shall be galvanised.
/ Metallic Strips
  1. Polymeric material used as reinforcing strips for load bearing reinforced soil structures shall satisfy the following conditions:
/ Polymeric Strips
(i)The Reinforced Soil Wall (RSW) System shall be a Roads and Maritime Services NSW approved system available from:

(ii)There shall be 150mm minimum clear cover from the front of the concrete panel to the geosynthetic reinforcement embedded in the panel; and
(iii)The material shall be demonstrated by testing as sufficiently strong, stable and durable to satisfy the performance and design requirements. Refer Specification 201, QUALITY SYSTEMS for details of the required testing.
(iv)The reinforced soil wall system shall be approved by the Main Roads Western Australia Senior Engineer Structures;
  1. No less than 4 weeks prior to the installation of any polymeric strips, the Contractor shall certify to the Superintendent that the Contractor has met all the requirements of clause 802.06.3.
/ HOLD POINT
802.07CEMENT STABILISED LAYER
  1. Where specified, the cement stabilised layer below the abutment sill beams shall be selected granular fill complying with the BACKFILL Clause of Specification 801 EXCAVATION AND BACKFILL FOR STRUCTURES, with the addition of 100kg cement per cubic metre of fill. The cement stabilised layer shall be uniformly mixed and compacted to a minimum of 96% of maximum dry density.

802.08ELECTROCHEMICAL PROPERTIES OF REINFORCED FILL MATERIALS (BACKFILL)
  1. The reinforced fill material shall meet the electrochemical requirements specified in Table 1.

Table 802.01
Soil Property / Allowable Limits
pH / 5-10
Chloride Content (mg/kg) / <200 dry land
<100 submerged
Sulphate Content (mg/kg) / <1000 dry land
<500 submerged
Resistivity (saturated)
(ohm.cm) / >1000 dry land
>3000 submerged
Notes: Submerged values shall be used where the structure is permanently or regularly submerged. Otherwise, dry land values shall be used. Submergence does not include marine environments.
802.09 – 802.25NOT USED
DESIGN
802.26GENERAL
  1. The MSE System shall be designed in accordance with AS 4678 to support the loads from the abutment as shown on the Drawings and in accordance with the requirements of AS 5100. Borehole information is provided in Annexure 802A.

  1. The bridge superstructure shall be independently supported on piles or columns founded below the reinforced soil block so as to support the bridge in the event of loss of MSE wall backfill due to washout or any other event. Piers and columns shall be fully fixed at the connection to the sill beam, if used, and in all cases designed to carry full abutment bending and axial loads, with provision for up to 1.0m loss of MSE wall backfill under the top of the piles or columns for the full width of the superstructure.

  1. The top of all MSE walls and the area adjacent to the abutment, including associated wingwalls, shall be mortar limestone pitched in accordance with Specification 406 ROCK PROTECTION, for 1.0m width to prevent ingress into the reinforced soil block.

  1. Geotextile or equivalent membrane approved by the Superintendent shall be used to prevent loss of MSE wall backfill through facing panel joints. The membrane design life shall be at least that of the bridge (100 years minimum).

802.27TENDER SUBMISSION
  1. Tenderers shall submit with their tenders sufficient details of their proposed MSE System to enable a full technical and aesthetic assessment to be made of its suitability. In particular this should address:

  1. anticipated design life (100 years minimum required)

  1. anticipated movements over the life of the structure (vertical and horizontal)

  1. safety factors adopted for the design

  1. requirements for fill material

  1. proposed shape and surface finish of facing panels and

  1. proposed reinforcing elements

with independent supporting evidence as appropriate.
802.28FULL DESIGN DOCUMENTATION
  1. The Contractor shall be responsible for the design and preparation of all detailed specifications and Drawings for the manufacture and construction of the MSE structures.

802.29 – 802.40NOT USED
INSTALLATION
802.41COMMENCEMENT
  1. At least 4 weeks prior to carrying out any work on the MSE abutments or walls the Contractor shall supply to the Superintendent full details of the proposed system, including four copies of all Drawings and specifications together with certification that the design has been checked and verified by an independent geotechnical engineer experienced in this form of construction.
/ HOLD POINT
802.42INSTALLATION
  1. The MSE system shall be installed in accordance with the approved documented design.

802.43 – 802.80NOT USED
AS BUILT AND HANDOVER REQUIREMENTS
802.81 – 802.90NOT USED
CONTRACT SPECIFIC REQUIREMENTS
802.91 – 802.99NOT USED

ANNEXURE 802A

BOREHOLE INFORMATION

  1. Borehole information is summarised or available as follows:

GUIDANCE NOTES

FOR REFERENCE ONLY – DELETE GUIDANCE NOTES FROM FINAL DOCUMENT

  1. All edits to downloaded Specifications shall be made using Track Changes, to clearly show added/deleted text.
  1. If all information relating to a clause is deleted, the clause number should be retained and the words “NOT USED” should be inserted.
  2. The proposed documents with tracked changes shall be submitted to the Project Manager for review, prior to printing the final batch of documents. When this final printing is carried out, the tracked changes option is to be turned off.
  3. Before printing accept all changes in the document, turn off Track Changes and refresh the Table of Contents.
  4. The Custodian of this specification is the Structures Design and Standards Engineer.
  1. BOREHOLE INFORMATION (Clause 802.26)
  2. Where available, Annexure 802A can be used to provide summary details of borehole information. If this information is extensive, particularly if on large format drawings, a suitable document to present this type of data is the “Information for Tenderers”.
  3. DESIGN (Clauses 802.26 to 802.28)
  4. The outline details listed should also be included by Tenderers in the appropriate Tender Schedule in the Tender Submission Document.
  5. Full design details and verification shall be supplied by the Contractor by the time stated.

CONTRACT SPECIFIC REQUIREMENTS

The following clauses are to be placed under the CONTRACT SPECIFIC REQUIREMENTS, as required. After inserting the clause, change the clause number and heading to style “H2 SP” so it appears in the Table of Contents.

XXX.XXSUB HEADING (H2 SP)
  1. Insert text (Main Table SP)
/ Keyword SP
  1. Insert text (Main Table SP)

XXX.XXSUB HEADING (H2 SP)
  1. Insert text (Main Table SP)

  1. Insert text (Main Table SP)

AMENDMENT CHECKLIST

Specification No. / 802 / Title: / MECHANICALLY STABILISED
EARTH WALLS / Revision No:
Project Manager: / Signature: / Date:
Checked by: / Signature: / Date:
Contract No: / Contract Description:
ITEM / DESCRIPTION / SIGN OFF
Note: All changes/amendments must be shown in Tracked Changes mode until approved.
Project Manager has reviewed Specification and identified Additions and Amendments.
CONTRACT SPECIFIC REQUIREMENTS addressed? Contract specific materials, products, clauses added? (Refer Specification Guidance Notes for guidance).
Any unlisted materials/products proposed and approved by the Project Manager? If “Yes” provide details at 16.
Standard clauses amended? MUST SEEK approval from Manager Commercial.
Clause deletes shows as “NOT USED”.
Appropriate INSPECTION AND TESTING parameters included in Spec 201 (Text Methods, Minimum Testing Frequencies verified).
ANNEXURES completed (refer Specification Guidance Notes).
HANDOVER and AS BUILT requirements addressed.
Main Roads QS has approved changes to SMM.
Project Manager certifies completed Specification reflects intent of the design.
Completed Specification – independent verification arranged by Project Manager.
Project Manager’s review completed.
SPECIFICATION GUIDANCE NOTES deleted.
TABLE OF CONTENTS updated.
FOOTER updated with Document No., Contract No. and Contract Name.
Supporting information prepared and submitted to Project Manager.
Further action necessary:
Signed: / (Project Manager) / Date:

Document No: DXX#XXXXPage 1 of 11

Contract No: XXX/XX [Contract Name]