MCU14/0024 - Response to Information Request - Attachment 4

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.

The builder must ensure the stability of neighbouring/existing structures is maintained through not
undermining their foundations. This is achieved via restricting any excavations to above a line
radiating downwards at an angle of 4 in 1.5 (vertical to horizontal) from the base of the
foundation/structure to be protected.

 

Any new vegetation including trees planted adjacent the structure should follow the recommendations
appended to this report.

6 FOOTING AND SLAB SPECIFICATIONS

Footing Details

All footings must be founded a minimum of 300mm into the NATURAL MEDIUM DENSE SILTY SAND (shown
shaded on the attached log sections). Dimensions and reinforcement requirements are detailed on the
structural plans and details.

Where the NATURAL MEDIUM DENSE SILTY SAND is deep or is covered by the introduction of fill, the footings
are to be increased in depth to reach this level. Alternatively the footings can be supported on piers founded
at or below the founding level. Refer to the structural plans for details.

Drilled Piers Supporting the Footings

Where the NATURAL MEDIUM DENSE SILTY SAND is deep or to be covered by fill the footings can be
supported on drilled concrete filled piers founded at a minimum of 300mm into the NATURAL MEDIUM DENSE
SILTY SAND. The size and spacing of these piers is nominated on the structural plans.

Where drilling piers is not practical the footings could be supported on steel screw piers.

Floor Slab Details

The thickness and reinforcement for slabs on ground are shown on the structural plans.

SCG Consulting Engineers 3 SCG Ref: 23277(S)