Geotech 95141.00.R.001

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•       It is considered that the majority of materials won from excavations on site where free of organic
        and deleterious material will generally be suitable for reuse as bulk fill provided the moisture content
        of the soils on placement approximates the OMC.
•       Imported fill material, if required, should be a good quality select fill material of low plasticity and
        well graded with a maximum particle size of 75 mm. The use of clayey imported fill material will
        increase the estimated ground surface movements due to moisture variation and the site
        classification.
•       Approved structural fill should be placed in layers not exceeding 0.2 m ‘loose’ thickness, with each
        layer compacted to a minimum density index of 75% or a minimum dry density ratio of 98% relative
        to Standard compaction. Unbound pavement gravel should be compacted to a minimum dry density
        ratio of 100% relative to Standard compaction.
•       Field density testing should be carried out to confirm the standard of compaction has been achieved
        and the placement moisture content. The frequency of testing should be in accordance with
        AS 3798. Level 1 inspection and testing of fill must be undertaken where the fill is to support
        buildings or pavements.

The above procedures will require geotechnical inspection and testing services to be employed during
construction by an experienced and competent geotechnical testing authority. It is recommended that
earthworks inspection and testing services that will be required during earthworks construction be
carried out by DP.



6.2       Batter Slopes

Very loose to loose sands have the potential to ‘collapse’ unexpectedly in a trenching situation. All
excavations will need to be battered for stability and prior to personnel entering the excavation.
Temporary excavations less than 1 m depth may remain vertical for short periods of time, provided
moisture conditions are favourable at the time of construction and provided there are no loads, services,
structures or traffic located within close distance to the crest of the excavation. Formwork may be
required to prevent loose material slumping into open excavations.

Temporary unsurcharged batter slopes should be no steeper than 2.5H:1V. Where groundwater
seepage is encountered, batter slopes will need to be considerably flatter.

The above temporary batter slopes are suggested with respect to slope stability only, and do not allow
for lateral stress relaxation which may result in movement of nearby inground services or shallow
footings. If such services are settlement-sensitive, and are located near the crest of the excavation, then
the excavation may have to be positively supported.

Long term slopes may need to be flattened to 3H:1V or less, in order to allow vehicle access for
maintenance of grass. It is recommended that all batters incorporate crest and toe drainage. The batters
should also be covered with topsoil and vegetation to provide long term erosion protection.




    Geotechnical Investigation, Proposed Youngcare Facility                                   95141.00.R.001.docx
    32 Viewland Drive, Noosa Heads                                                                   January 2021