Slope Stability Report

Dean & Vanessa McDonald                                                                         21505-001-Rev0
                                                                                                4 February 2022

structures or fill batters and not as concentrated discharge upslope of any neighboring
structures/embankments. The platform should be graded slightly (minimum 1V:100H) back ‘into’ the
exposed rock batter slope to drain appropriately to the diversion drainage system and not allow over topping
of the downslope fill batters.

Subsurface drainage must be installed behind any retaining walls (e.g. slotted ‘aggi’ pipe wrapped in filter
‘sock’ placed in gravel backfill). Depending on matters such as the extent of drainage installed and site-
specific groundwater conditions, the designer must make an assessment of hydrostatic pressure to be
accounted for in the design of the retaining structure.

It would be prudent to construct a rock dissipator or rock contour drain at the drainage outlet point(s) to
minimise erosion. Drains should be directed to discharge towards the natural drainage lines.
Subsurface disposal of stormwater must not be undertaken (including infiltration pits).


5.0     SUMMARY & CONCLUSIONS
Based on the findings of our assessment we consider that there would be a Low Risk of slope instability
affecting the proposed shed, subject to implementation of the recommendations given in this report.



6.0     LIMITATIONS
Your attention is drawn to the document Limitations, which is attached to this letter report.

Please contact the undersigned should you wish to discuss any of the above matters.

Yours faithfully,

TECTONIC GEOTECHNICAL PTY LTD




Jarrad McVey BEng (Civil) (Hons)                           Ashley Davey RPEQ 8159
Geotechnical Engineer                                      Director/Principal Geotechnical Engineer


Attachments: DCP Reports
             Qualitative Terminology for Use in Assessing Risk to Property
             Some Guidelines for Hillside Construction
             Limitations




                                                       12/12


[OCR of page images]
Dean & Vanessa McDonald 21505-001-RevO
4 February 2022

 

structures or fill batters and not as concentrated discharge upslope of any neighboring
structures/embankments. The platform should be graded slightly (minimum 1V:100H) back ‘into’ the
exposed rock batter slope to drain appropriately to the diversion drainage system and not allow over topping
of the downslope fill batters.

Subsurface drainage must be installed behind any retaining walls (e.g. slotted ‘aggi’ pipe wrapped in filter
‘sock’ placed in gravel backfill). Depending on matters such as the extent of drainage installed and site-
specific groundwater conditions, the designer must make an assessment of hydrostatic pressure to be
accounted for in the design of the retaining structure.

It would be prudent to construct a rock dissipator or rock contour drain at the drainage outlet point(s) to
minimise erosion. Drains should be directed to discharge towards the natural drainage lines.

Subsurface disposal of stormwater must not be undertaken (including infiltration pits).

5.0 SUMMARY & CONCLUSIONS

Based on the findings of our assessment we consider that there would be a Low Risk of slope instability
affecting the proposed shed, subject to implementation of the recommendations given in this report.

6.0 LIMITATIONS
Your attention is drawn to the document Limitations, which is attached to this letter report.
Please contact the undersigned should you wish to discuss any of the above matters.

Yours faithfully,

TECTONIC GEOTECHNICAL PTY LTD

MM

Jarrad McVey BEng (Civil) (Hons) Ashley Davey RPEQ 8159
Geotechnical Engineer Director/Principal Geotechnical Engineer

Attachments: DCP Reports
Qualitative Terminology for Use in Assessing Risk to Property
Some Guidelines for Hillside Construction
Limitations

 

tectenic

12/12