Appendix E_Geotechnical Investigation

                                   PROPOSED UNIT DEVELOPMENT
                                   PRECINCTS E2 & F, NOOSA SPRINGS

Buildings and structures located on the flatter part of the site (i.e. Area 2) are expected to be founded in
future controlled and certified fill (fill placed after removal of existing uncontrolled fill). The allowable bearing
capacity (ABC) will be dependent on the type and compaction of the future fill material, however, it is
anticipated that an ABC of at least 100 kPa would be achievable.

Foundations and allowable bearing capacities must be confirmed following inspection by a Geotechnical
Engineer during construction.

All footings should found such that they are not adversely affected by any adjacent excavations, batter
slopes, trenches (e.g. possibly associated with light pole structures along then northern boundary of the
boardwalk), or retaining walls that are not designed to support loads. To minimise the potential for any
adverse interaction effects, footings should found at least below a plane extending 1 m horizontally from the
base of trenches/excavations/retaining walls, then rising up at 1V:1H. This requirement is illustrated in Text
Figure 11 below.




Text Figure 11: Footing depth required to minimize risk of undermining

Footing bases must be cleaned following mechanical excavation to expose undisturbed materials over the
full base area. It is recommended that footings be inspected by an experienced engineer prior to placement
of steel reinforcement to confirm allowable bearing pressures and cleanliness of excavations.

If any soil conditions encountered during construction are found to differ from those noted in the geotechnical
investigation, Tectonic should be notified immediately and an inspection carried out to determine if changes
to footing design are required.

7.4        Retaining Structures
Retaining walls may be required for both residential construction and the new roads depending on the extent
of earthworks.

Design for temporary or permanent retaining structures could be carried out using a triangular pressure
distribution applicable to the wall type and based on the parameters listed in Table 3. The values in Table 3
assume that the walls are fully drained and no allowance is included for hydrostatic pressures, construction
loading, up-slope footing loadings, the effects of sloping ground and backfill compaction stresses.
Table 3: Retaining Structure Design Parameters
                                                                      Lateral earth pressure coefficients
                             Unit       Friction
 Retained material          weight       angle
                                                              Ka                         Ko
                            (t/m3)     (Degrees)                                                            Kp
                                                       (Cantilever wall)         (Non-yielding wall)
 Very loose/loose sand       1.8           30                 0.33                       0.5                3.0
 Medium dense (or
                             1.9           34                    0.3                    0.45                3.3
 denser) sand
 Future Fill                  *             *                     *                       *                  *
Note:    * depends on fill material type and level of compaction.

Retaining structure footings must be founded as recommended in Section 7.3.2.


11 November 2015
Report No. 15193-002-Rev0                                   14