RFI - slope stability reporting

RECOR Pty Ltd                                                                                 22393-001-Rev0
                                                                                              26 October 2022

It is therefore recommended that site specific static load testing be conducted from screw piles, if adopted, at
a minimum. Where tension or compression capacity developed in the footings is critical for the future
structure (e.g. resistance to uplift forces from high winds), then cyclic load tests (including measurement of
deflections under tension and compression cycles) should also be undertaken prior to construction.
Kentledge for static testing, or simulated cyclic loads, should prove the piles to a minimum of two times the
expected working load within tolerable deflections.

All footings should be founded such that they are not adversely affected by or affect any adjacent
excavations, trenches, retaining walls, or in ground structures that are not designed to support building loads
(e.g. sewer along front boundary and cutting/retaining wall on neighbouring block). Footings should be
founded at least below a plane extending 1 m horizontally from the base of trenches/excavations/retaining
walls/swimming pool, then rising up at 1V:1H, as illustrated in Text Figure 9.




                           Text Figure 9: Footing depth required to prevent undermining

If any soil conditions encountered during construction are found to differ from those noted in the geotechnical
investigation, Tectonic should be notified immediately, and an inspection carried out to determine if changes
to footing design are required.

Should bored piles be adopted, it is essential that the piling contractor have a ‘mud bucket’ or similar to
enable clean out of the pile bases. It is recommended that footings be inspected by an RPEQ prior to
placement of steel reinforcement and pouring of concrete to confirm allowable bearing pressures and
cleanliness of excavations.




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