1-22276-01 site plan

Project No. 1-22276                                                                                                                  Page | 28
February, 2020
Ref: 1-22276, 2020-02-28, BR VER 2
Wessel Petroleum Pty Ltd – GEOTECHNICAL INVESTIGATION - Proposed Service Station Reconstruction, 52-54 Mary Street and Weyba Road,
Noosaville




    6.6 Retaining Wall

           6.6.1       General

It is recommended that any retaining structure is designed in accordance with AS 46-2002
‘Earth Retaining Structures’. Section 3 of this code outlines the design requirements for these
retaining structures which specifically includes both Ultimate and Serviceability Limit Modes, it is
recommended that the retaining structures be assessed for each of these modes.

Walls should be designed in accordance with Australian Standard 4678-2002 earth-retaining
structures.

Various retaining wall options could be considered for construction. The option chosen will
depend on several factors including:-

          Loading on wall
          Space requirements
          Founding conditions
          Earthworks requirements

The lateral earth pressure distribution that affects the retaining walls on the site will depend
upon the following parameters:-

          Insitu and backfill material properties
          Design water regime at the rear of the wall
          Wall and cut geometry
          Surcharges affecting the wall
          Wall type
          The structural bracing of the wall and the timing of backfilling behind the wall.

           6.6.2       Pressure Distribution

The following situations should be considered:-

          For cantilever walls, which allow some movement at the top, (i.e. at least 0.005H in
           clays) the active case (Ka) applies with a triangular distribution in both the short and
           long term situations.
          For cantilever walls which cannot tolerate this movement, the at rest case (Ko) applies
           with a triangular distribution in both the short and long term situations.

Figure 4 refers.




                                                                                                            SOIL SURVEYS