Response to outstanding issues - Revised Geo-Environmental Investigation-compressed · MCU25/0020

Contents
1.    Introduction ............................................................................................................................................................ 1
2.    Proposed Development ....................................................................................................................................... 1
3.    Site Description ......................................................................................................................................................3
4.    Method of Investigation ......................................................................................................................................6
      4.1 Fieldwork ...................................................................................................................................................................... 6
      4.2 Environmental Laboratory Testing ..................................................................................................................... 6
5.    Investigation Findings .......................................................................................................................................... 7
      5.1 Regional Geology ..................................................................................................................................................... 7
      5.2 Subsurface Conditions ............................................................................................................................................ 7
      5.3 Groundwater............................................................................................................................................................... 8
      5.4 Aggressivity Laboratory Test Results................................................................................................................. 9
6.    Engineering Assessment .................................................................................................................................... 10
      6.1 Revetment Wall Global Stability........................................................................................................................ 10
      6.2 Earthworks ................................................................................................................................................................. 10
           6.2.1   Site Preparation and Trafficability................................................................................................... 10
           6.2.2   Excavations .............................................................................................................................................. 11
           6.2.3   Material Re-Use ..................................................................................................................................... 11
           6.2.4   Filling ......................................................................................................................................................... 12
      6.3 Temporary and Permanent Retention ............................................................................................................ 12
           6.3.1   Temporary Batters ................................................................................................................................ 12
           6.3.2   Temporary and Permanent Retention Systems ......................................................................... 13
      6.4 Building Foundations ............................................................................................................................................ 14
           6.4.1   Settlement Analysis .............................................................................................................................. 14
           6.4.2   Footing Options..................................................................................................................................... 16
           6.4.3   Raft Footing Design ............................................................................................................................. 16
           6.4.4   Piled Footing Design............................................................................................................................ 16
           6.4.5   General ...................................................................................................................................................... 17
           6.4.6   Site Classification .................................................................................................................................. 17
           6.4.7   Earthquake Design Considerations ................................................................................................ 18
      6.5 Permanent Drainage.............................................................................................................................................. 18
7.    Acid Sulfate soil assessment ............................................................................................................................. 19
      7.1 Information on Acid Sulfate Soil ....................................................................................................................... 19
      7.2 Desktop Study.......................................................................................................................................................... 20
            7.2.1    Geology and Groundwater ................................................................................................................ 20
      7.3 Regional ASS Mapping ......................................................................................................................................... 20
      7.4 ASS Investigation Results..................................................................................................................................... 21
      7.5 Risk Characterisation ............................................................................................................................................. 21
8.    Acid Sulfate Soil Management......................................................................................................................... 21
      8.1 Training and Orientation...................................................................................................................................... 22
      8.2 Management of Disturbed Material ................................................................................................................ 22
            8.2.1   Verification Testing............................................................................................................................... 22


Geo-environmental Investigation Proposed Residence
4 June 2025 | 25040-001-Rev1                                                                                                                                                            iii