Reference Documents

                                               PROPOSED SUBDIVISION
                                               41 TALLOWWOOD PLACE, BLACK MOUNTAIN

            6.0         GEOTECHNICAL RECOMMENDATIONS
            General recommendations to help maintain the stability of the site are given in the document Some
            Guidelines for Hillside Construction, which is attached in Appendix C.

            6.1         Site Layout and Geotechnical Constraints
            A recommended building area is defined in Text Figure 13. No building, filling or effluent disposal areas shall
            be undertaken outside of this area unless assessed and approved by a geotechnical RPEQ prior to
            construction. The proposed driveway will need to be repositioned away from the exclusion zone. An
            indicative new driveway alignment is also illustrated on Text Figure 13. The final lot boundaries should be
            designed to ensure the exclusion zone is wholly within one allotment (i.e. not on a site boundary), to reduce
            the consequence of potential future instability.




                      Recommended Low Risk Building Area     Exclusion Zone




                         Not Assessed



                                                                         Not Assessed



                         Indicative new driveway alignment




            Text Figure 13: Construction exclusion zones and recommended building area, base map courtesy of NC

            To achieve a Low Risk of instability, the following is recommended:
                      No structures, driveways, filling, or wastewater irrigation areas are to be constructed within the
                       exclusion zone shown in Text Figure 13, unless assessed and approved by a geotechnical RPEQ.
                      Proposed Operational and Building Works must be reviewed and approved by a geotechnical RPEQ
                       once detailed design drawings are available.
                      All retaining walls exceeding 1 m high and/or subject to surcharge loads must be engineer designed
                       and certified, which must include an assessment of global and internal stability.
                      Unretained fill heights shall be limited to no more than 1 m and shall be located on ground sloping at
                       less than 10°. All fill to be placed on ground sloping at 10° or steeper must be fully supported by an
                       engineer designed and certified retaining structure. Filling must not exceed 1.5 m high unless
                       assessed and approved by a geotechnical RPEQ.
                      Design and construction of footings shall be undertaken in accordance with Section 6.3.2.
                      Formal drainage should be constructed to ensure all stormwater is directed away from the proposed
                       structures and effluent disposal areas.

            Although the remediated landslide is within the recommended exclusion zone, to prevent water ponding
            around the area it is recommended that the existing track is removed, and the ground surface is graded such
            that stormwater can freely drain into the drainage line downslope. Care must be taken to ensure that
            grading works do not undermine the toe of the rock fill embankment and they should not extend beyond the
            southern property boundary.



             22 May 2023
             Report No. 23099-001-Rev0                                  13

Document Set ID: 22826802
Version: 1, Version Date: 23/02/2024