Reference Document - MCU26 0001 & OPW26 0002 - AS PUBLISHED · MCU26/0001

        Specific platform design would be required prior to mobilisation and trafficking of any heavy mobile
        plant on the site (e.g. mobile cranes, concrete pumps or piling rigs)
        Construction areas and surrounds should be graded to shed surface water runoff.

        6.2.2           Excavations
        Excavations through the soils encountered in the boreholes should be achievable using conventional
        earthmoving plant (e.g. excavators with toothed buckets). Temporary unsurcharged cuts in the very
        loose to loose sand could be formed at 1V:2H, and at 1V:1.5H in medium dense (or denser) sand for
        batters up to 3 m in height. Flatter batters or temporary retention may be required if groundwater
        seepage is encountered or if sloughing of dry sand occurs at the batter surface. Deeper unretained cuts,
        if required, should be specifically assessed by Tectonic, unless supported by temporary retention
        measures.
        If filling or permanent cuts exceed 1 m, then these must be retained. Permanent cut and fill batters up to
        1 m high shall not exceed 1V:2.5H. Any permanent soil and fill batters will require erosion protection
        (e.g. revegetation or surface protection).
        It is likely that above temporary batter slopes will not be able to be achieved, due to spatial restraints,
        and so temporary shoring will be required (e.g. sheet, contiguous or secant piles), as per the
        recommendations in Section 6.4 below. Excavations in close proximity to existing structures, including
        on neighbouring properties, will need to be specifically designed to prevent undermining. It is
        recommended that footing exposures or confirmation of foundations via certified building plans be
        undertaken to assess the possibility of undermining. If undermining is a potential issue the existing
        structures may need to be underpinned or excavations may require temporary shoring.
        The advice of a suitably qualified and experienced RPEQ structural engineer must be sought regarding
        any potential undermining and design and construction of any underpins/temporary shoring (if
        required).
        The above recommendations do not supersede any existing safety regulations or legislation applicable to
        excavations (e.g. limits on personnel entry into trenches).
        Due to the highly permeable nature of the sands at this site, stormwater is expected to rapidly infiltrate
        the ground, making un-sealed surface drainage ineffective for the control of flows. Any sealed areas
        should be graded to ensure free drainage of stormwater away from construction areas, and to a control
        point(s).

        6.2.3           Filling
        The natural sandy soils where free of deleterious materials (e.g. vegetation, building debris etc.) may be
        reused as structural fill, subject to appropriate moisture adjustment. It should be noted that compaction
        of such relatively ‘clean’ sands as structural fill requires the addition of substantial volumes of water
        (‘flooding’) combined with the use of vibratory compaction equipment (typically a smooth drum roller or
        heavy vibrating plate).
        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


        Geotechnical Investigation
        30 January 2026 | 25408-001-Rev0                                                                              12
Document Set ID: 25158026
                  24528612
Version: 1,
         2, Version Date: 10/09/2026
                          13/02/2026