Development Application part 2 Application Forms REC11/0145

    Evidence of previous :           SCG Consulting have previously provided advice regarding some minor
    Soil Movements                   landslip that had occurred in the south east comer of the allotment. The
                                     area was remediated with the construction of a stone filled gabion wall
                                     and improved drainage facilities surrounding the area.


    LANDSLIP MECHANISMS

    Landslip is generally defined as the movement of a mass of rock or soil down a slope.

    It is generally considered to occur when the strength of the soil or rock mass to support itself is exceeded
    causing movement to occur within the mass.

    This loss of strength can occur as a result of numerous circumstances. These include, but are limited to
    the following:-

            Seismic Activity
E           Erosions effects such as wind or fluid scour
            Soil Saturation from rainfall events or defective drainage measures
            Construction/Earthworks activities
            Groundwater variations/movements
            Previous Landslips

    The nature of landslips vary with site specific conditions and failure mechanism
    occur. Appendix B provides some diagrammatic examples of various landslips.

    The speed of landslips can vary greatly from millimetres per year to a number of meters in a matter of
    minutes.   Once again this characteristic is governed by site specific conditions and the failure
    mechanism causing the slip to occur.

    The allotment is situated within a massive Aeolian sand bed of Quaternary age. As a general observation
    dunal horizons such as these are stable where;

                    The natural slope is less than the angle of repose for sand (300)
                    Vegetation exists to protect from wind generated scour
                    The drainage pattern is such that there is no risk of fluvial scour.

    These horizons can become unstable when Aeolian or fluvial scour erode slopes to angles greater than
    300, particularly when coincident with vegetation removal.


    LANDSLIP HAZARD ASSESSMENT

    For our assessment we utilize the Guidelines For Landslip Risk Management Framework as provided by
    the Australian Geomechanics Society, in their journal of March 2007. Descriptions used by this
    framework can be found appended to this report.

    Using the Qualitive Risk Analysis Matrix (refer appendix) we have established the following
    characteristics for the allotment.

          Landslip Mechanism                          Transitional or Rotational Landslip

    We consider a potential landslip mechanism will consist of either a Rotational or Translational
    Landslide or Creep movement within the sloping profile. Diagramation representation of these
    mechanisms are appended to this report. We are of the opinion that this movement could occur
    beyond the eastern boundary of the allotment.

          Likelihood of Landslip                      Unlikely to Rare