Attachment F - Geotechnical Report

                             PROPOSED COMMERCIAL & RESIDENTIAL DEVELOPMENT
                             30-32 DOONELLA ST, TEWANTIN

4.0       METHOD OF INVESTIGATION
4.1       Fieldwork
A total of five boreholes were drilled across the site (designated BH1 to BH5) using a 4WD mounted
rotatory rig, owned and operated by Ground Drill Pty Ltd, utilising solid flight augering methods. Boreholes
BH1 and BH2 were drilled to depths of 6 m below ground level (BGL). Boreholes BH3 to BH5 were drilled
to depths of 3 m BGL. In situ soil strength was assessed by conducting dynamic cone penetrometer (DCP)
testing adjacent to and/or within each borehole, along with pocket penetrometer (PP) testing on clay
samples recovered from the auger and undisturbed (U50) tube samples.

The fieldwork was undertaken in the presence of an experienced engineering geologist from Tectonic on
5 June 2018. The engineering geologist was responsible for logging soil profiles in accordance with AS1726
Geotechnical site investigations, making groundwater observations, and recovering soil samples.
Boreholes were backfilled with auger cuttings on completion, with excess spoil mounded at the surface.

Borehole locations are shown in Figure 1, attached at the end of this report. Boreholes reports are attached
in Appendix A, together with explanatory notes.

4.2       Laboratory Testing
Undisturbed tube and bulk disturbed soil samples were dispatched to Geotech (SC) Pty Ltd, a NATA
accredited geotechnical laboratory located in Kawana, for geotechnical testing. Laboratory testing was
undertaken in accordance with Australian Standard AS1289 Method for Testing Soils for Engineering
Purposes and comprised:

         2 (No.) Shrink-Swell Index tests to assess soil reactivity to moisture content changes.
         1 (No.) single point CBR test, following a 4-day soak, to determine pavement subgrade strength.

Laboratory certificates are attached in Appendix B.

Laboratory results are summarised and discussed in Section 5.3.




22 June 2018
Report No. 18151-001-Rev0                             4