Information response - GEOTECH REPORT

Report: 15960, May (1 Page 6

4.2 Earthworks
Performance Criteria: -
¢ Retain natural contours wherever possible.
FILLING
¢ Minimise height.
¢ Strip vegetation and topsoil and key into natural slopes prior to filling.
¢ Use clean fill materials and compact to engineering standards.
Q Batter to appropriate slope or support with engineered retaining wall.
¢ Provide surface drainage and appropriate subsurface drainage.
CUTS
¢@ Minimise depth.
© Support with engineered retaining walls or batter to appropriate slope.
¢ Provide drainage measures and erosion control
ROCK OUTCROPS & BOULDERS
4 Remove or stabilise boulders, which may have unacceptable risk.
@ Support rock faces where necessary.
Acceptable measures: ~
4.2.1 General Earthworks - The proposed building area is to be stripped of all organic material
and/or material that will inhibit construction. The residence is proposed as slab on ground, therefore a cut
of around (0 metas will be required. This will result in the residential structure being part on cut
materials and part on placed fill.
The following details should be considered: -
¢ Earthworks should be prepared in accordance with the guidelines of AS3798 ~ Guidelines
on earthworks for commercial and residential developments.
¢ A positive drainage gradient is to be maintained over the building areas.
be) Spoon drains to be installed at the toe of cut embankments
Fill batters should grade at not Iess than 1:2 (V:H).
Peat batters which ate unretained should grade at not less than 1:1¥% (V:H).
¢ Exposed surfaces should be vegetated to reduce the opportunity for runoff scour
Excessive earthworks proposed on this site may require an “Operational Works” permit, which must be
obtained from the Local Authority.

4.2.2 Filling - Site preparation of filled areas will include stripping of topsoil and closely
benching the exposed slope prior to placenent-of fill in accordance with AS3798. Fill areas should be
For minor fill areas (less than 1.0 metres), the
7:2 (V: H) and vegetated immediately to reduce the

prepared to support minimum loads of at
batters should be prepared to a maximum gradé
opportunity for scour.

   

4.2.3 Retention - Cut embankments could engage weathered rock. Rigid or flexible retention
methods can be employed where necessary. A spoon drain above the cut area should remove overland
flow with suitable drainage media placed between the retention system and exposed soil. Unretained cut
embankments can grade at 1:14 {V:H)} for clays/gravels and 1:V2 (V:H) for competent rack.

 

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