Compiled Reference Documents - MCU24/0153 & OPW24/0202

        Construction areas and surrounds should be graded to shed surface water runoff. Swale drains should
        be constructed along the crest and toe of any cuts, and above fill batters, where possible. Drains are to
        be graded to discharge collected waters to a control point(s) before release into existing stormwater
        infrastructure.
        It should be noted that during wet weather, the natural soils may cause sediment run-off. Appropriate
        erosion and sediment control measures must be installed prior to commencement of earthworks at this
        site.

        6.2.2           Excavations
        Excavations through the existing soils should be achievable using conventional earthmoving plant (e.g.
        small or larger excavators with toothed buckets). Temporary, unsurcharged cuts in the very loose to
        loose sand could be formed at 1V:2H and at 1V:1H 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 cuts, if required, should be
        specifically assessed by Tectonic.
        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).
        Temporary batter slopes would not be able to be achieved in places, due to spatial restraints, and so
        temporary shoring will be required (e.g. sheet piles or contiguous 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 as well as 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 existing sandy soils (fill and natural) 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).




        Proposed Unit Development
        30 September 2024 | 24265-001-Rev0                                                                          12
Document Set ID: 23376055
Version: 1, Version Date: 28/11/2024