271117 Techtonic GeoTech Cooroy Mtn Rd

Mr Ken Freeman                                                                                    17385-001-Rev0
                                                                                                27 November 2017



6.0     SUMMARY & CONCLUSIONS
Based on the findings of our assessment we consider, from a geotechnical viewpoint, that the site is suitable
for the proposed development and that there should be a Low Risk of slope instability. This advice is subject
to implementation of the recommendations given in this report, in particular:

       All fill batters and cuts greater than 1 m high should be retained by engineer designed and certified
        retaining walls.
       The carport, garage, and porte cochere should have as a minimum high level footings taken down to
        medium dense (or denser) / very stiff (or stiffer) material at approximately 0.5 m BGL
       The retaining walls for the fill area north of the house will require bored piles or similar, socketing at
        least 1 m in to very stiff or hard residual clay below the existing fill, approximately 3 m BGL
       The possible two storey extension will require bored piers taken at least 1 m in to weathered very
        low strength rock (or stronger).
       Foundation excavations and stripped subgrades in fill areas must be inspected by a suitably qualified
        geotechnical engineer
       Ensuring that stormwater flow is directed at least 10 m down slope of the building envelope,
        especially regarding the possible two storey extension to the north-east; and the filling work north of
        the house
       The front wall of the existing swimming pool should be broken out and drainage installed to prevent
        saturation of pool backfill and foundation soils.



7.0     LIMITATIONS
Your attention is drawn to the document Limitations, which is attached to this letter report.

Please contact the undersigned should you wish to discuss any of the above matters.

Yours faithfully,

TECTONIC GEOTECHNICAL PTY LTD




Robert Gibb BSc (Hons)                                        Scott Davis BEng CPEng RPEQ 16439
Engineering Geologist                                         Senior Geotechnical Engineer


Attachments: Site Plan
             Test Pit Logs and Explanatory Notes
             Laboratory Test Results
             Qualitative Terminology for Use in Assessing Risk to Property
             Some Guidelines for Hillside Construction
             Limitations




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