Development Application part 2 Application Forms REC11/0145

      LANDSLIDE RISK MANAGEMENT                                                                                                         AGS SUB-COMMITTEE


                                                                                  APPENDIX A

                                                 SOME GUIDELINES FOR HILLSIDE CONSTRUCTION

                                      GOOD ENGINEERING PRACTICE                                                              POOR ENGINEERING PRACTICE
      ADVICE
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      PLANNING
                                      aving obtained georec'nical advice, plan the development with the risk                 Plan development without regard for the Risk
                                  I arising Gam the identified hazards and consequences in mind.
      DESIGN AND CONSTRUCTION
      I IOL'SC DES; : Y.I Use t cA:;;k ;truuures which incorporate properly designed brickwork, timber                       Floor plans which require extensive cutting and
                          or steel frames, timber or panel cladding.                                                         filling.
                          Considcr use of split levels.                                                                      Movement intolerant structures.
                          Use decks for recreational areas where appropriate.
      SITE CLEARING       Retain natural vegetation wherever practicable                                                     Indiscriminately clear the site.
      ACCESS &            Satisfy requirements below for cuts, fills, retaining walls and drainage                           Excavate and fill for site access before
      ORIYEWAYS           Council specifications for grades may need to be modifie(i                                         geotechnical advice.
                          Drivewsv and parking areas may need to be fully supported on pliers.
      EARTHWORKS          Retain natural contours wherever possible                                                          Indiseriminant bulk earthworks.
                  CUTS    Minimise depth                                                                                     Large scale cuts and benching.
                          Support with engineered retaining walls or batter to appropriate slope.                            Unsupported cuts.
                          Provide drainage measures and erosion control.                                                     Ignore drainage requirements
                  Ftt1S   Minimise height                                                                                    Loose or poorly compacted fill, which if it fails.
                          Strip vegetation and topsoil and key into natural slopes prior to filling.                         may nnw a cnnsidera^!c dint=ice ineitatittg
                          Use dean nth materials and compact to engineering standards                                        onto property below.
                          Batter to appropriate slope or support with engineered retaining wall.                             Block natural drainage lines.
                                                                                                                                                           an opsot
                                                                                                                             Include stumps, trees, vegetation, topsoil,
                                                                                                                             boulders, building rubble etc in fill.       _
         Roctc OUTCROPS               Remove or stabilise boulders which may have unacceptable risk.                         Disturb or undercut detached blocks or
            & BOULDERS                Support rock faces where necessary.                                                    boulders.
      RETAINING                       Engineer design to resist applied soil and water forces                                Construct a structurally inadequate will. such as
      WALLS                           Found on rock where practicable.                                                       sandstone flagging, brick or unreinfurced
                                      Provide subsurface drainage within wall backfill and surface drainage on slope         blockwork.
                                      above.                                                                                 Lack of subsurface drains and wcepholes
                                      Construct wall as soon as possible after cut/fill operatiorL
      E' )fr:` ;C-S                   Found within rock where practicable.                                                     •,:n.!    . _-; ,;               -,
                                      Use rows of piers or strip footings oriented up and down slope.
                                      Design for lateral creep pressures if necessary.
                                      Backfill footing excavations to exclude ingress of surface water.
      SWiivIM NG POOLS                Engineer designed.
                                      Support on piers to rock where practicable.
                                      Provide with under-drainage and gravity drain outlet where practicable.
                                      Design for high soil pr:--.u-ex which may develop on uphill side whilst there
                                      may be little or no lateral support on downhill side                                                                                         _
      DRAINAGE
P J           SuRFACe                 Provide at tops of cut and rill slopes.                                               Discharge at top of fills and cuts.
                                      Discharge to street drainage or natural water courses.                                Allow water to pond 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 at changes of slope and/or direction.
               SUBSURFACE             Provide filter around subsurface drain.                                                Discharge roof runoff into absorption benches.
                                      Provide drain behind retaining walls.
                                      Use flexible pipelines with access for maintenance
                                      Prevent inflow of surface water.
                      Se.o is &       ! rsualy reqt_irsss pu.:.p-c:t or mains setter systems; absorptions trenches may       :itsc'1srge silage           onto and into slopes

                      St1LLAoe        be possible in some areas if risk is acceptable.                                       Use absorption trenches without consideration
                                      Storage tanks should be water-tight and adequately founded                             of landslide risk.
      EROSION                         Control erosion as this may lead to instability.                                       Failure to observe earthworks and drainage
      CON i ROL &                     Revegetate cleared area.                                                               recomnxndations when landscaping
      I.ANI).SC'APING
      DRAWINGS AND SITE VISITS DURING CONSTRICTION
                                      Building Application drawings should be viewed by geotechnical consultant
      SITE VISITS                     Site Visits by consultant may be appropriate during construction/                                                                            I

      INSPECTION AND:1lAlNTENA:NCE BY OWNER
      OWNER'S                         Clean drainage systems repair broken joints in drains and leaks in supply
      RES!'ONSIBILITY                 pipes
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                                                                                                                        Australian Geomechanics - March 2000                     91