geotech

                               PROPOSED UNIT DEVELOPMENT
                               9 BOTTLEBRUSH AVENUE, NOOSA HEADS

It should be noted that this modelling addresses the global stability of the proposed works; however, the
stability of the retaining walls must be addressed by others as part of detailed design.




Text Figure 9: Slope/W output for long term conditions



6.0      GEOTECHNICAL RECOMMENDATIONS
General recommendations to help maintain the stability of the site are given in the document “Some
Guidelines for Hillside Construction”, which is attached.

6.1       Development Limitations
It is anticipated earthworks will include cuts for the basement level of up to about 4 m deep in in the rear with
only minor filling expected to be required up to about 1 m in height to form finished surface levels. Should
proposed cuts/fills exceed this quantity, Tectonic must assess the impacts on slope stability before
construction.

6.2       Earthworks – General
6.2.1       Site Preparation and Trafficability
Following removal of the existing buildings and associated construction elements (e.g. footings, services,
etc.), any tree stumps and large roots should be ‘grubbed out’. Any organic rich topsoil and uncontrolled fill
should then be stripped and set aside. Based on the boreholes, topsoil stripping depths should generally
range between 0.1 m and 0.2 m BGL, with uncontrolled fill encountered to 0.8 m BGL (existing ground
levels) in borehole BH1. It is noted that vegetation debris (leaf litter) was observed in parts along the
southern boundary estimated to range up to about 0.6 m deep. Therefore, it is possible that deeper pockets
of topsoil or uncontrolled fill may exist and deeper, localised grubbing out of tree roots may be required.



13 July 2021
Report No. 21169-001-Rev0                                9