Geotechnical Report

                                                   Site Location




            Plate 1: Extract of geology online mapping sourced from QLD Department of Resources



4.2       Subsurface Conditions
Based on our review of GeoCon2012, our DCP test results and site observations, the pertinent aspects of the
subsurface conditions are summarised below:
          From the surface level in the rear yard, BH3 (GeoCon2012) encountered sandy fill which extended to
           a depth of approximately 1.8m below the existing surface levels. Based on the results of DCP3
           (GeoCon2012), the fill has been assessed to be poorly compacted. Assuming a similar subsurface
           profile the results of the remaining GeoCon2012 DCP tests and DCP101 and DCP102 completed by
           JKG have been interpreted to indicate that similar poorly compacted fill extends to depths between
           about 1.4m and 1.8m. We also note that in the absence of formal records of placement and density
           test results, the fill is regarded as “uncontrolled” as defined in AS2870-2011 “Residential slabs and
           footings”.
          Natural sands were encountered below the fill in BH3 (GeoCon2012) and based on the results of
           DCP3 the natural sands have been assessed to be loose. The results of the remaining GeoCon2012
           DCP tests and DCP101 and DCP102, assuming a similar subsurface profile, have been interpreted to
           indicate loose to medium dense and medium dense natural sands below the fill. Based on DCP101
           and DCP102 the natural sands were consistently medium dense below depths of about 1.5m
           (DCP101) and 2.0m (DCP102). The medium dense sands extended to the termination depth of
           DCP101 (3.9m) and DCP102 indicated that the sands improved to medium dense to dense below
           about 2.5m to the termination depth of 3.9m.
          No groundwater seepage was noted in BH3 (GeoCon2012) and the DCP rods were ‘dry’ when
           extracted during the JKG investigation. However, there is a wetland area to the north-east of the site,
           which is anticipated to have surficial or shallow groundwater levels particularly following heavy or
           prolonged rainfall events.




36409UR                                               3