220508-R001(B) Engineering and Services Report (OPW) · OPW23/0179

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clearance envelopes). Noting the requirements of Condition 30, Table 9.4.1.4 of the Planning
Scheme Parking Code only requires 3 carparks for this development, the provision of 5 compliant
carparks exceeds the minimum requirement and is considered a good outcome for future users of
the development.
A driveway longitudinal section has been provided and demonstrate the driveway grades meet the
requirements of AS2890.1 Section 2.6. Grade changes and transitions have been modelled also to
demonstrate that there is sufficient vertical clearance for vehicles to enter site and the basement. A
ground conflict report has been produced by the software to analyse the tracking of vehicles over
the design surface and shows that a B85 vehicle maintains clearance to the driveway surface at all
times. Minimum headroom as per AS2890.1 Section 5.3 is also demonstrated.
Works within the easement are as per previous drawing issues and require minimal works within the
adjoining lot, limited to extending the concrete pavement to connect the existing surface with the
subject site. The existing infrastructure in the adjoining lot does not require extensive modification
to facilitate access to the proposed development.


2.2     Pedestrian Access and External Works
The site is serviced by existing Council concrete footpaths across the Gympie Tce frontage and within
Council land adjacent to the northern boundary. The proposed works includes pedestrian access to
the existing path at the northern boundary, and construction of a new 2.0m wide concrete footpath
along the frontage of Gympie Terrace as per Condition 27 and 28. The Engineering Drawings refer to
Council Standard Drawing RS-065 for footpath construction details.



3.0 EARTHWORKS

3.1     Cut and Fill Operations
Earthworks will be required to deliver the proposed development and includes excavation for the
basement and installation of fill to achieve the design finished surface levels. The Engineering
Drawings include cross sections at key locations to demonstrate the depth of excavation and filling
as well as an earthworks map showing the extent and depth of earthworks/filling across the site.

3.2     Basement Excavation
The basement extents are shown on Engineering Drawings and require excavation below the existing
surface. The depth of excavation is less than 2.5m and will generate approximately 550m3 of spoil
to be taken off site. A Geotechnical Investigation and Report has been prepared by Pacific Geotech
and can be found in Appendix B. The report addresses the requirements of Conditions 39 and 40,
and informs the structural design. Structural Engineering drawings have been prepared by SCG
Consulting Engineers and can be found in Appendix C. These drawings detail retaining wall
structural details within the permanent works and provide a concept design for a contiguous pile
temporary retaining wall to enable the excavation of the basement. The final design and
implementation of the temporary works will be the responsibility of the construction contractor.

A detailed Groundwater and Acid Sulphate Soils Management Plan has been prepared by ADG
Consulting and can be found in Appendix D. The report addresses the requirements of Condition 32
specifically as well as other general development compliance outcomes.