Rfi - PG-2096, 2022-11-03, Gr Ver 3

 Project No. PG-2096                                                                                                    Page | 6
 March 2023
 Ref: PG-2096, 2022-11-03, GR VER 3
 Keith & Jeannette Ince – Geotechnical Stability Assessment - Proposed Residence, 22 Arakoon Crescent, Sunshine Beach




     •     Density testing should be carried out to check the standard of compaction
           achieved and the placement moisture content. The frequency and extent of
           testing should be as per guidelines in AS.3798-2007.
     •     All earthworks operations should be performed under Pacific Geotech’s
           supervision, in general accordance with the requirements of AS3798.

6.0 SITE CLASSIFICATION

Site investigation and laboratory test results indicate the development site would be
classified Class S in accordance with AS 2870-2011 'Residential Slabs and Footings',
from a reactivity perspective.

It is recommended that the readers satisfy themselves that the use of AS 2870-2011 is
applicable for the proposed design and the above site classification re-confirmed
following the completion of the bulk earthworks operation.

7.0 BUILDING FOUNDATIONS

Foundations

In order to provide a uniform and stable foundation and due to the site stability issues,
it is recommended a deepened foundation, incorporating either appropriately
founded pad footings or piers founded into medium dense or better sands be
adopted for the proposed constructions. Pad footings should socket a minimum
depth of 0.9m into the medium dense or better sands and piers should found a
minimum of 1.5m into the medium dense or better sands, if adopted.

Lateral Forces

In view of the global stability in the area, sloping natural terrain and the presence of
loose sands, it is recommended that all footing systems be designed to
accommodate forces due to potential soil creep within the surficial fill strata.

The potential lateral force due to creep in the soil strata may be determined from the
following:

Force                  =           1.5KpH2D

Where Kp               =           2.5

                      =           Soil Density=20kN/m3

           H           =          Depth of sands, a depth of up to 2.8m was indicated in
                                  the boreholes. Final depth subject to further
                                  geotechnical assessment at time of pier excavations.
           D           =           Footing/Pier Width (m) - perpendicular to slope