1-22276-01 site plan

Project No. 1-22276                                                                                                                  Page | 19
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




          Pavement gravels should be compacted to the following minimum density ratios as
           determined by AS 1289 Test 5.2.1 (Modified compaction):-
                  Base material               98%
                  Sub-base material           95%
                  Blanket material            95%
          Backfill to service trenches should be placed in uniform layers over the full width of the
           excavations, with the layers not exceeding 200mm loose thickness using wheeled plant
           and 100mm loose thickness using vibrating plates.
           The backfill material should be compacted to the above specifications for cohesive
           and/or cohesionless materials.
          Other comparable compaction specifications may be adopted for earthwork procedures;
           however, Soil Surveys Engineering Pty Limited should be consulted to confirm these.
          Consideration should be given to adopting a Level 1 earthworks control, in accordance
           with the requirements outlined in AS 3798-2007, for the earthworks preparation and
           filling operations to ensure the required civil specifications are met for structural support,
           and long term integrity of pavements. Level 1 supervision infers that the geotechnical
           testing authority provides a full time inspection and testing service on all earthworks on
           the project, or the section contracted for, and decides the locations and timing of the
           testing. On completion of the earthworks the geotechnical testing authority will provide a
           report certifying the fill, setting out inspections, sampling and testing that have been
           carried out and the locations and results thereof.
          Field density testing should be carried out to check the standard of compaction achieved
           and the placement moisture content. The frequency and extent of testing should be as
           per guidelines in AS 3798-2007, Section 8.0 or as directed by the Level 1 engineering
           supervisor.
          Sands should be compacted to achieve the required density index (AS 1289 Test Series
           5). Test method AS 1289 6.3.2 ‘Determination of Penetration Resistance of a soil using
           the 9kg Dynamic Cone Penetrometer’ is recommended to verify compaction using
           accepted density index correlation tables.

Earthworks Supervision

Engineering supervision of the earthworks operations by Soil Surveys Engineering Pty Limited
is recommended.

Following production of AS 3798-2007, the terms "Level 1 and 2 Supervision" have been
adopted in earthworks specifications to describe what could also be termed Engineering
Supervision. Whilst there is no particular problem with using these terms, there does not seem
to be wide agreement as to what Level 1 or 2 Supervision actually means or entails.

Regardless of terminology, it should be made clear in any earthworks specification as to what is
actually required in terms of certification.

It is recommended that the following objectives (as a minimum) be incorporated into the
earthworks specification:-




                                                                                                            SOIL SURVEYS