33522 soil report SCG 28050(S) · MCU18/0001

4     FINDINGS

The soil profiles encountered are shown on the attached borelog sections.

No water table was encountered during our testing program.

The sandy soils encountered are susceptible to collapse when unconfined. This may effect excavations and
result in additional earthworks and increased concrete volumes. Temporary shoring or Forma-Tube may be
required to retain the sands prior to concreting.

The samples classified on-site were assessed as having negligible plasticity, therefore laboratory testing was
considered unnecessary.

We have assessed the expected differential movement of the soil profiles encountered to be the equivalent of a
site with a Ys of less than 20mm.


The following foundation material will provide a safe bearing capacity (100 kPa) for buildings within the scope of
AS 2870-2011 and is shown shaded on the attached logs;

           FOUNDATION MATERIAL - NATURAL MEDIUM DENSE SILTY SANDS

5     SITE PREPARATION DETAILS

We recommend scraping this site free of all organic material, topsoil and debris so that the proposed construction
area is levelled (within acceptable limits).

Where a retaining wall is required, a cut batter of 1 to 2 (vertical to horizontal) in the sand profile taken from the
base of the proposed wall should be excavated. These earthworks must incorporate shallow surface spoon
drains at the base and along the high side of the cut. Drains must have an efficient outflow down-slope and clear
of the construction area. The exposed face should also be protected against the potential for stormwater erosion.
Should these recommendations be un-achievable the builder should seek guidance from this office on temporary
shoring, benching or other suitable techniques. Backpropping to retaining walls should be provided throughout
the backfilling and compaction process.

Areas where existing structures or trees are removed shall be backfilled with engineer approved fill material
compacted to achieve a minimum relative field density of 95% and be in accordance with AS2870-2011. Where
trees are removed prior to construction the moisture conditions of the soils must be allowed to normalise across
the site prior to commencing foundation preparations.

Any loose or soft material uncovered in the site preparation shall be removed and replaced with approved fill
material compacted in accordance with AS2870-2011, or alternative measures to be provided by the engineer.

We recommend using a footing system as per the attached plans and details on the prepared construction pad.

For the design to be valid the cut/fill line must be in the position shown on our footing plan. Any variation must
be brought to the attention of this office before continuing work.

Site drainage during construction is important. Stormwater run-off should be diverted away from any foundation
excavations and not be able to pond within 5.0m of the building footprint. Temporary piping or spoon drains or
other practical methods should be used. Please refer to the Appendices to the rear of this report for drainage
management.

The final surface profile should fall away from any slab on ground for a minimum of 1.5m at a grade of no less
than 1 in 20. Refer to appendices for drainage recommendations.

Where site drainage and landscaping does not conform to the specifications of AS 2870-2011 and CSIRO
Information Service Sheet BTF-18 significant damage to the building can be expected. A single copy of this
document is issued with the original issue of this report. Please consult your builder or contact this office to obtain
a copy.




      SCG Consulting Engineers                                2                                     SCG Ref: 28050(S)