slope stability report

INTRODUCTION

SCG Consulting Engineers have been commissioned to provide a Slope Stability Assessment for the above
allotment. The assessment considers the existing state of the allotment and any possible effects that the
proposed works will have on this site.

The proposed works are detailed by Dennis Hill Architect in plans 049 dated 10/12/2020 and consists of a
proposed duplex consisting of a mix of slab on ground and suspended timber frame floors.


SITE DESCRIPTION

A desk top study of the site confirms the following:-

   -   The site is located in an area identified as a ‘Landslip Hazard’ on the Noosa Council’s Landslip Hazard
       Map. A portion of the site is identified as having a ‘Moderate Landslip Risk’.

   -   Level contours provided on the proposed building plans indicate an average fall within the site of 20-25%.

SCG Consulting Engineers have conducted several soil tests along Grant Street. The following soils profile are
encountered.

                            :   LOOSE SILTY SANDS INCREASING IN DENSITY WITH DEPTH

Our walkover confirmed the following characteristics-

Site Slope                  :   A visual assessment of the surface grades within the allotment using a hand held
                                inclometer suggests grades in the order of 20% exist across the proposed
                                construction site. The measured grades are consistent with the contours indicated
                                on the proposed construction.

Vegetations                 :   Vegetation consists of grasses and scattered trees.

Slope Shape/Location :          The surface profile across the allotments slope faces are generally LINEAR
                                DIVERGENT.

Drainage                    :   The surface drainage is good, sub-surface drainage is good.         There was no
                                indication of ground water seepage or rising water pressure.

                                Stormwater flows from upslope of the allotment will be intersected and captured by
                                the road reserve.

Earthworks                  :   There is no existing earthworks apparent.

Adjacent Structures         :   Adjacent structures on the neighbouring properties appear to be a mix of slab on
                                ground and suspended timber framed floors.

Evidence of previous        :   None apparent.
Soil Movements


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.




 SCG Consulting Engineers                                  2                                    SCG Ref: 30378(SL)