Appendix 5. Geotechnical Engineering Report [As Published] · 132007.2399

October 2007                                             - ii -                                  077682076(AB)


                                     TABLE OF CONTENTS

SECTION                                                                                                       PAGE

1.0    INTRODUCTION .......................................................................................... 1
2.0    SITE DESCRIPTION .................................................................................... 1
3.0    METHOD OF INVESTIGATION................................................................... 2
       3.1      Preliminary Assessment ..........................................................................2
       3.2      Field Work ...............................................................................................2
       3.3      Geotechnical Laboratory Testing.............................................................3
       3.4      ASS Laboratory Testing ..........................................................................3
4.0    INVESTIGATION FINDINGS ....................................................................... 4
       4.1      Preliminary ASS Assessment..................................................................4
       4.2      Subsurface Conditions ............................................................................4
       4.3      Groundwater............................................................................................5
       4.4      Geotechnical Laboratory Testing.............................................................6
5.0    ACID SULFATE SOILS ................................................................................ 6
       5.1      Investigation Aims ...................................................................................7
       5.2      Soil Sampling...........................................................................................7
       5.3      Field pH (pHF) and Peroxide pH (pHFOX) .................................................7
       5.4      Summary of Soil Analysis Results...........................................................8
       5.5      ASS Extent and Severity .........................................................................9
       5.6      Preliminary Recommendations..............................................................10
                5.6.1 Treatment of Excavated Soil......................................................10
                5.6.2 Stockpiles and Handling ............................................................12
                5.6.3 Excavation for Services .............................................................12
                5.6.4 Extrusion of ‘Marine’ Clays Adjacent Fill Areas .........................13
                5.6.5 Dewatering.................................................................................13
6.0    GEOTECHNICAL ASSESSMENT ............................................................. 13
       6.1      Subdivision Development ......................................................................13
                6.1.1 Earthworks .................................................................................13
                6.1.2 Retaining Structures ..................................................................15
                6.1.3 Preliminary Pavement Design ...................................................15
                6.1.4 Drainage ....................................................................................16
                6.1.5 Site Management & Erosion Potential .......................................16
       6.2      Residential (Building) Development ......................................................17
                6.2.1 Earthworks .................................................................................17
                6.2.2 Site Classification & Footings ....................................................17
                6.2.3 Drainage ....................................................................................17
       6.3      Further Investigation ..............................................................................17
7.0    IMPORTANT INFORMATION .................................................................... 18




                                           Golder Associates