Appendix B - Global Stability Assessment Report

                                                    - 10 -
                                                                                      Job No: ME21/032



                              Table 5 – Global Stability Analysis Results

                                                                    Factor
                                         Batter Subsurface            of
         Batter Location                                                     Figure      Comments
                                               Profile              Safety
                                                                    (FOS)
                                         Natural – Stiff Clay of                        FOS <1.5, not
     Existing 5.5m high cut,                 High Plasticity                            acceptable for
                                                                     1.32      1
  approximately 380 slope angle         (Extremely Weathered                              long term
                                                 Granite)                                  stability
                                         Natural – Stiff Clay of                         FOS > 1.5,
         5.5m high cut,
                                             High Plasticity                            acceptable for
 supported by 3m high retaining                                      1.65     1a
                                        (Extremely Weathered                              long term
             wall 1)
                                                 Granite)                                  stability
                                        Fill – Stiff Clay of High                        FOS > 1.5,
    3m high, 2.5H:1V fill batter        Plasticity Sourced from                         acceptable for
                                                                     1.52     1b
      behind retaining wall              Cuts in the Extremely                            long term
                                          Weathered Granite                                stability
 Benched cut batter comprising
                                         Natural – Stiff Clay of                         FOS > 1.5,
 4m high lower batter, and 3.5m
                                            High Plasticity                             acceptable for
 high upper batter both with 380                                     1.50     1c
                                        (Extremely Weathered                              long term
 slope angle, separated by a 2m
                                               Granite)                                    stability
           wide bench
                                         Natural – Stiff Clay of                         FOS > 1.5,
       4m high cut batter,                   High Plasticity                            acceptable for
                                                                     1.51     1d
  approximately 380 slope angle         (Extremely Weathered                              long term
                                                 Granite)                                  stability
                                        Fill – Stiff Clay of High                       FOS <1.5, not
   Existing 4.5m high fill batter,      Plasticity Sourced from                         acceptable for
                                                                     1.12      2
  approximately 350 slope angle          Cuts in the Extremely                            long term
                                          Weathered Granite                                stability
                                        Fill – Stiff Clay of High                        FOS > 1.5,
 4.5m high fill batter, flattened to
                                        Plasticity Sourced from                         acceptable for
         2.5H:1V or 220                                              1.68     2a
                                         Cuts in the Extremely                            long term
     (Landslip located in fill)
                                          Weathered Granite                                stability
  4.5m high fill batter, flattened to
                                         Natural – Stiff Clay of                         FOS > 1.5,
           2.5H:1V or 220
                                            High Plasticity                             acceptable for
 (Deep landslip located in natural                                   1.68     2b
                                        (Extremely Weathered                              long term
     soil/extremely weathered
                                               Granite)                                    stability
               granite)
                                         Natural – Stiff Clay of                         FOS > 1.5,
  4.5m high fill batter, supported
                                            High Plasticity                             acceptable for
  by 3m high retaining wall with                                     1.55     2c
                                        (Extremely Weathered                              long term
   7m deep pile embedment 2)
                                               Granite)                                    stability
 Notes:
    1) A 3m high fill batter at an approximate angle of 220 (2.5H:1V) is located behind the crest of
        the retaining wall.
    2) A 1.5m high fill batter at an approximate angle of 150 is located behind the crest of the
        retaining wall.




Ref: 27222-rev 1                                                             MORRISON GEOTECHNIC
Mr Geoff Hussin