Attachment C - Geotechnical investigation

APPENDIX G - SOME GUIDELINES FOR HILLSIDE CONSTRUCTION

ADVICE

GOOD ENGINEERING PRACTICE

POOR ENGINEERING PRACTICE

 

GEOTECENICAL
ASSESSMENT

Obuin advice Som a quabfed oxpensnced geotechnical practttonar 2t sarly
segs of plannmg and before wie works.

Prepare Getiiled plan and iast ute wor: Defcre
geotechnical advice.

 

 

 

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DESIGN AND CONSTRUCTION

 

Having obtained advice, plan the development with the mk
arising fom the identiGed hazards and consequences in mind

Plan development withort regard for the Risk.

 

 

‘Use flexible scucture: which incorporate properly designed brickwork timber
or steal Samees, timber or panel cladding

Flocr plans which require emamive cuthag and

 

 

 

 

Pus

Provide dramase mozs=re; and erosion contol.

Manzaise beight.

Strip vegetation and topsoil and key into astuzal slopes prior to Gillins
‘Use clean 60) matecials and compact to engineering standards.
Batter to appropriate slope or support with engineered retaining wall
Provide surface drainags and appropriate subvariace drainage.

ERE DESIGN” | Consader wie uk split levels Movement intolerant vructures

Use decks for recreation: areas where appropriate.

SITE CLEARING Retus sataral vegetation wherever practicable. Tndiscriminately clear the site.

ACCESS & Satisfy requirements below for cuts, fil, retaimng walls 2nd dramage. Excavate and G0 for wite access before
DRIVEWAYS Council specificatoms dor grades may need to be modified geotechnical advice.

Driveways and parking areas mosy need to be filly supported on piers.

EARTHWORES Retain aateral contours wherever posible. Todtscuiminstory bulk sarthworks.
Manzase dopa. Large scale cut: and benches

Cure ‘Support with enamecred retaining walls or batter to appropriate slope. Unsapported cuts.

| Imers dramazerequamests
Loose or pocsly compacted G2 whick if it fails,

may flow a comsidesable distance including
omto property below.

Block natural drainage line:

Fill over oxisting vegstaton and topscil.
Incinds stumps, toss, vegetation, topsoil
boulders buildins mbble otc in fill.

 

Rock Ourcrors

Remove or stabilise boulders which may have unacceptable nak.

Dismrb or undercut detached block: or

 

 

 

 

 

 

 

 

DRAWINGS AND SITE VISITS DURING CONSTRUCTION

& Boers Support rock Sces where necessary. boulders.
Enminser dewsn to veuist applied toil and water forces. Construct a stractarally inadequate wall such a
RETAINING Found on rock where le sandstones flagging, brick or umroinforced
WALLS Provide subsurface drainage within wall backSill and surface deeimage om slope | blockwork.
above. Lack of sabsurface drains and weepholes.
Conseuct wall as scon as possible after cut/fill operation
Found within rock where practicable. Found om topseél, looss SE detached boulders
FOOTINGS ‘Use rows of pier: or stip footing: oriented up and down slops. or undercut cliffs.
Desi for interal cosep pressures if necessary.
Back footing excavations to exclads mares: of surdace water
Engineer dewimed.
Support on pues to rock whare practicable.
SWIMMING POOLS | Provide with under-drainage and smvity drain outlet where le.
Desian for igh soil presvarss which may develop im aphil unde saat shorn
cozy be Little or no Isteral sqpport on downhill sids.
DRAINAGE
Provide st tops of cat and Gill slopes. Discharge at top of ills and cuts.
Discharge to street drainage or natural water comrues. Allow water to pond om beach areas.
SUBS ACE Provide gemerel falls to prevent blockage by siltation and mccrporate silt traps.
‘Line to minimise infilration and make dloxible where possible.
stractares to diss! at chanaes of slope and/or d=ecton
Provide Glter around sabvarface draa. Discharge rood ranoff into absorption trenches
Sumanrace Provide dram behind retainms walk.
. Use Hexible pipelines with access for mamtenance
Prevent inflow of sarface water.
Sernc & Unaally requis: pamp-out cr mains sewer systems; absorption teaches may | Dischares millsas directly onto and mito slopes.
SULLAGE be possible im some areas if risk is acceptabis. ‘Use absorption wenches without comsiderstion
ios | Storage tanks should be water-tight and adequately founded of landslide risk.
EROSION Control erosion as this may lead to instability. Faire to observe oasthworks and dramaso
CONTROL & Revegetats cleared area Tecommendations when landscaping.
LANDSCAPING

 

 

 

 

 

 

 

DRAWINGS Building Application drawings thould be viewed by aeotechmical consultant
SITE VISITS Site Visas by consultant may be appropriate gums comstrucson.
INSPECTION AND VIENANCE BY OWNER
CWNER'S Clean dremage systems, separ broken joits in drm: and lesks m supply
RESPONSISLLITY i

pipes
Whore structural distress is evident ses advice
Ti seepage observed, determine camses or sesk advice on consequences.