SUPERSEDED Compiled Reference Document - MCU24 0153 & OPW24 0202 (As Published)

        Should importation of fill be required, it is recommended that such fill should comply with the following:
        ▪     Minimum CBR of 10%
        ▪     Maximum plasticity index of 15%
        ▪     Shrink-swell index ≤ 1%
        ▪     Maximum particle size of 100 mm
        Any fill should be compacted at moisture contents within the range of ±2% of optimum moisture
        content for Standard Compaction. Fill material should be placed in 250 mm thick (loose thickness) layers
        and be compacted by repeated rolling using a minimum 4 tonne smooth drum roller (or equivalent, with
        vibration on if safe to do so) to achieve a dry density ratio of at least 98% of the maximum Dry Density
        Ratio (DDR), based upon the Standard Compaction method, or a Dry Density Index of at least 75%.
        Confirmatory compaction testing must be carried out at regular intervals. A minimum of two tests per
        vertical lift is recommended where structural fill heights are to exceed 300 mm. Further details for
        control and testing of fill are given in Australian Standard AS 3798-2007 Guidelines on Earthworks for
        Commercial and Residential Developments.
        Fill embankment edges must be over-filled by 0.5 m (horizontally) and then trimmed back to well
        compacted material.


        6.3             Building Foundations
        6.3.1           Indicative Site Classification
        Site classifications for footing design are determined in accordance with AS 2870-2011 Residential Slabs
        and Footings, and depend on the depth of cut / fill undertaken at a site, variations in the natural soil/rock
        depths, and the reactivity of the in situ soil / rock and any imported fill materials. It should be noted that
        the proposed works are outside of the scope of AS2870.
        Based on the results of the investigation, the site is classified as Class P in accordance with AS 2870-2011
        Residential Slabs and Footings, due to the presence of uncontrolled fill and poor bearing capacity soils at
        shallow depths. However, if not for these factors, the site would have the characteristics of Class S, with
        the estimated characteristic surface movements (‘ys’) ranging up to about 20 mm. Due to the potential
        variability in subgrade density a site classification of Class M is recommended in relation to assessment
        of flexibility requirements for ground slab, footing and plumbing design.

        6.3.2           Footing Design
        No design loadings were available at the time of reporting. Footings for the proposed development and
        any ancillary structures (e.g. retaining walls, etc.) must penetrate through any fill materials and unsuitable
        natural soils (i.e. very loose to loose sands) to found at least 0.5 m into medium dense (or denser) natural
        sands. Such materials were encountered below depths between about 1.4 m and 2.6 m BGL (existing
        ground levels) in the boreholes. Thus, piled footings will be required unless excavations expose such
        materials at or near foundation subgrade level (e.g. as anticipated in deeper basement cut areas).
        Piles so founded may be designed using an allowable end bearing pressure of 500 kPa. High level
        footings, where achievable in deeper cut areas, may be designed using an allowable bearing pressure of
        100 kPa provided that they are founded in the natural medium dense (or denser) sands. Settlement under
        such loads is expected to be in the order of up to 20 mm or 1% of footing width.



        Proposed Unit Development
        30 September 2024 | 24265-001-Rev0                                                                          13
Document Set ID: 23376055
Version: 1, Version Date: 28/11/2024