RFI - Attachment C - Slope Stability Assessment and Geotechnical report · MCU20/0026

Project No. 1-22543                                                                                                          Page | 16
June, 2020
Ref: 1-22543, 2020-05-20, BR SSA VER 1
Sanya Holdings – Slope Stability Assessment and Geotechnical Report - Proposed Residence, 40 Park Crescent, Sunshine Beach




6.0 ENGINEERING ASSESSMENT

    6.1 Civil Works

           6.1.1       Trafficability and Site Preparation

The fieldwork for this investigation was carried out by a ute mounted drilling rig (at street level)
and hand equipment (due to the steep slope which limited access onto the site for our
machinery). It should be noted that some problems may be anticipated during wet weather for
even light weight 4WD vehicles.

The soils on site are sensitive to repetitive vehicle loading and water (i.e. they will lose strength
through repetitive vehicle loading or if they become overly moist or wet). Further, seepage may
also result in a subsequent loss of strength. This may limit trafficability and create difficulties for
earthworks operations. This situation would be more pronounced if rainfall followed initial
clearing, stripping and grubbing.

It is recommended that after stripping, clearing and grubbing, the exposed surface in the
construction area be proof rolled (where appropriate) to assist in identifying weak areas and to
improve trafficability.

Maintaining adequate drainage conditions is essential. It should be ensured that runoff is
diverted away from the construction area to prevent ponding of water.

Potential trafficability problems with this site should not be underestimated. The site will
very quickly become untrafficable if appropriate seepage and drainage control
measures, along with construction practices appropriate for site conditions, are not
maintained.

The contractor should fully inform himself of the ground conditions on site prior to
commencement of earthworks. This requirement should be explicit in any earthworks
specifications or contract.

Working Platforms For Tracked Plant and Heavy Construction Vehicles

The scope of Soil Surveys Engineering’s study DOES NOT include the design of a working
platform for heavy construction vehicles or heavy tracked plant on or around the site.

Detailed design of a working platform should be carried out considering the operation of actual
machinery proposed to be used. This is particularly important when considering the use of
heavy piling rigs and heavy cranes - the piling/crane contractor should be consulted regarding
their requirements.

           6.1.2       Earthworks

It is envisaged that the basement platform will be created with maximum cuts of up to approx.
4.0m to 5.0m with possible backfilling of up to approx. 2.5m required behind permanent
retaining structures.

Earthwork procedures should be carried out in a responsible manner in accordance with AS
3798-2007 'Guidelines on Earthworks for Commercial and Residential Developments'. It is
recommended that the earthworks contractor make themselves familiar with site conditions.



                                                                                                               SOIL SURVEYS