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

 Project No. PG-2096                                                                                                    Page | 10
 March 2023
 Ref: PG-2096, 2022-11-03, GR VER 3
 Keith & Jeannette Ince – Geotechnical Stability Assessment - Proposed Residence, 22 Arakoon Crescent, Sunshine Beach




compaction be required, then wall stresses will be well in excess of Ko and temporary
propping should be used.

It is recommended that all retaining walls be drained for full height in order to minimise
hydrostatic pressure build-up behind the wall. Additional guidelines on wall drainage
are provided in Appendix G of AS 4689-2002.

9.0 SITE MANAGEMENT

To maintain the long term performance of the structure, good management of the
soil conditions and the development is vital throughout the life of the development.

The following are some specific comments with respect to site management.

     •     It is important that the site be well drained. The ground around the building
           should slope away at 1 in 20 for 2 metres and then fall to the stormwater system
           to prevent ponding of water adjacent to the building.
     •     Founding soils should not be allowed to become saturated.
     •     Service trenches under the buildings should be kept to a minimum. Saturation
           of the on-site material will result in an increase in potential ground surface
           movements.
     •     Footings should be poured immediately after excavation. If footings cannot
           be poured on the same day as excavation, a blinding layer of 50mm thickness
           is recommended.
     •     Trees, garden beds and other vegetation should be planted at a distance at
           least equivalent to three quarters of their mature height away from the
           structures. This will assist in minimising shrinkage movements in the expansive on-
           soils.

10.0 STABILITY EVALUATION

   10.1 General

The overall stability evaluation of the proposed building site has been carried out on
a broadscale basis by visual inspection and from the subsoil information from the
boreholes undertaken.

No signs of mass/global instability were noted across the proposed development sites
during the field assessments.

Building Type

The proposed structure is to comprise of a rigid/blockwork undercroft structure with
lightweight, flexible structure over the remainder of the site. Ground floor construction
should be designed as fully suspended.