07/0604 - Response to Information Request [As Published] · 142007.604

SOME GUIDELINES FOR HILLSIDE CONSTRUCTION

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GOOD ENGINEERING PRACTICE POOR ENGINEERING PRACTICE
ADVICE
GEOTECHNICAL Obtain advice from o qualified, experienced geatechnical consultant at Prepare detaited plan and start site works
ASSESSMENT carly stage of planaing and before sits works, before geotechnical advice,
TLANNING _
SITE PLANNING Having oblained geotechnical advice, ptan the development with the risk Plon development withovt regard for the
arising from the identified haznrds and consequences in mind, tisk,
DESIGN AND CONSTRUCTION
HOUSE DESIGN Use flexible structures which incorporate properly designed brickwork, Floor plans which require extensive
timber or steel frames, timber or panct chdding, cutting end filling.
Consider use of split tevels. Movement intolerant strectores.
Use decks for recreational areas where appropriate,
SITE CLEARING Retain natural vegetation wherever practicable. Indiscriminately clear the site,
ACCESS & Satisfy requirements below far cuts, fills, retaining walls and drainage, Excavate and fill for site access before
DRIVEWAYS Council specifications for grades may need to be modified. geotechnical advice.
Driveways and parking oreas may need to be fully supported on piers.
EARTHWORKS Retain natural contours wherever passible. lodiscriminant bulk earthworks.
Cuts | Minimise depth. Large scale cuts and benching.
Support with engincered retaining walls or batter to oppropriate slope. ‘Unsupported cuts.
Provide drainage measures and erosion control. Ignore dratnage reqtitements.
Minimise height. . Loase or poorly compacted fill, which if it
: Strip vegetation and topsoil and-imy irto natural-clopes.prios-ta-fillings- fails,.mzy.flow a considerable distance.
~~ Use clean fill materials and compact toengineering standards,” -- ~~ -| inchuding onto property beluw.——————-
Batter to appropriate slope or support with engineered retaining wall. Block natural drainage lines.
Provide surfice drainage and appropriate ubaurface drainage, Fill over existing vegetation and topsoil.
Include stumps, trees, vegetation, topsail,
. boulders, building rubble efc, in HL
Rock Ourcrors& | Remave or stabilise boulders which may have unacceptable risk. Disturb or undercut detached blocks or
BOULDERS | Support rock faces where necessary, boulders,
RETAINING WALLS | Engineer design to resist applied soil and water forces. Construct a structurally inadequate wall
Found on rock where pmeticable. - such as sandstone flagging, brick or
Provide subsurface drainage within wall backfill and surface drainage on | srelnforned blockwork,
slope above, Lack of subsurface drains and weephales.
Construct wall as soon as possible after cur/fill operation.
FOOTINGS Found within rock where procticable, Found on topsoil, loose fill, detached
Use rows of piers or strip footings aricated up and down slope, boulders or andercut cliffs.
Design for lateral creep pressures if necessary,
Bockfill footing excavations to exclude ingress of surface water.
SWIMMING POOLS Engineer designed.
Support on piers to rock where practicable.
Provide with under-drainage and gravity drain outlet where practicable,
Design for high soil pressures which may develop on uphill side whilst
there may be Little or no lateral support an downhill side,
DRAINAGE
SuRFACE | Provide at tops ofcut and Gill slopes. Discharge ot top of fills and cuts,
Discharge to street drainage or natural water courses. Allow wotee to poud on bench areas,
Provide general falls to prevent blockage by siltation and incorporate silt
traps.
Line to minimise infiltration and make flexible where possible.
. Special structures to dissipate energy ot changes of slope and/or direction.
SupsurFACe } Provide filter around subsurface dmin. Discharge mof runoff inte absorption
Provide drain behind retaining walls. trenches,
Use flexible pipelines with access for maintenance,
Prevent inflow of surface water,
Servic & SULLAGE | Usually requires pump-out or mains sewer systems; absorption teaches Discharge sullape direcily onto and into
may be possible in some oreas if risk is acceptable, slopes,
Storage tanks should be water-tight and adequately founded. Use absorption trenches without
consideration of Landslide risk,
ERGSION CONTROL | Control crosion as this may lead to instability. Failure to observe eartlworks and
& LANDSCATING Revegetate cleared area, drainage recommendations when
landscaping.
BRAWINGS AND SITE VISITS DURING CONSTRUCTION
DRAWINGS Building application drawings should be viewed by geotechnical
consultant,
SITE VISITS Site visits by connitnt may be oppropriate during construction.
INSPECTION AND MAINTENANCE BY GWNER
OWNER'S Clean drainage systems; repair broken joints in drains and leaks in supply
RESPONSIBILITY pipes.
Where structural distress is evident seek advice,
Ifscepage observed, determine causes or seek advice on consequences.

 

 

 

 

This table is an extract ftom LANDSLIDE RISK MANAGEMENT CONCEPTS AND GUIDELINES as presented in Australian Geomechanics,
Volume 35 Number 1, March 2000, which discusses the matter more fully,

Golder Associates

68029 Some Guidelines for Hillside Construction Revised 12 July 2004

G:AQA Docs\Lecal Office Forms\Some Guidelines for Hillside Constuction.doc