Avocet Pde OPW - App E Slope · OPW20/0092

                                                                                               37 636 783 527

                                                                                                  PO BOX 851
                                                                                      Moffat Beach, QLD, 4551
                                                                              [email protected]
                                                                                www.geotechengineering.com.au




•   The area should be stripped of uncontrolled fill, soft, overly wet, foreign, or otherwise
    deemed unsuitable material (material that is potentially compressible) down to a relatively
    stiff dry base ensuring no organics material is present.
•   Stripped areas must be inspected by the geotechnical testing authority (GTA) to ensure no
    soft spots or loose zones are present. This should be done with the use of a loaded body
    truck or 12 tonne roller as a minimum. Areas showing signs of movement under the action
    of the testing equipment should be either over excavated and replaced with select fill or
    conditioned onsite through tyning, blending or other suitable methods.
•   Although no standard exists for the moisture content of soils, it is recommended that the
    site soils be placed at or near optimum moisture content (OMC) for general earthworks
    operations. This increases efficiency during earthworks operations. A range of +/- 2% of
    OMC is recommend for general earthworks.
•   Where site soils are proposed for use as fill in other areas, won material will need to have
    a maximum particle size of 75 mm or be observed to break down under the energy of
    compactive equipment.
•   Fill materials should be placed in relatively horizontal layers with a maximum placement
    thickness of 200 mm. The materials should be compacted to a minimum dry density ratio
    of 95% relative to Standard compactive effort.
•   Highly plastic clays at this site will be very sensitive to the presence or lack of moisture and
    therefore care should be used to place the material within the range nominated and to a
    maximum dry density of 102% relative to Standard compactive effort. Where this does not
    happen, the material could readily swell, soften, or be subject to significant trafficability
    issues.
•   Fill material will be subject to potential settlement post placement. Well compacted fill
    placed in accordance with AS3798 and otherwise, good earthworks procedure should
    typically be subject to settlement in the order of 0.5% to 1.0% of the fill thickness over a
    log cycle of time.


5.2 Site Movement
The results of the investigation, previous experience, and published correlations were used to
estimate the maximum characteristic ground surface movement (ys) value in accordance with
AS 2870.


The results of the calculations indicate that at the time of the investigation, a ys value
approximately equal to less than <20 mm is considered suitable; however, the site must be
classified as Class P given the requirement for slope stability assessment.


It is important to understand that numerous things can affect and consequently increase or
decrease the ys value for a site.



29 Apr 2020                                                          Proposed Residnetial Dwelling