Slope Stability Report

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

4.3   Footing Design
Footings for the proposed shed and any ancillary structures (e.g. tanks or retaining walls) should penetrate
through any fill, and residual soils, to found a minimum of 0.3 m into very low strength (or stronger) rock.
Footings so founded may be designed using an allowable bearing pressure of 400 kPa. It is understood that
the shed slab and footings will found directly on/into such rock.
Footing design should also account for potential soil reactivity, to be assessed by others.

All footings should found such that they are not adversely affected by any adjacent excavations, trenches, or
retaining walls that are not designed to support building loads. Footings should found at least below a plane
extending 1 m horizontally from the base of trenches/excavations/retaining walls, then rising up at 1V:1H, as
illustrated in Text Figure 12.




                 Text Figure 12: Footing depth required to prevent undermining or surcharge loading

Footing bases must be cleaned following mechanical excavation to expose undisturbed materials over the
full base area. A suitably qualified and experienced RPEQ engineer must inspect the footing excavations to
confirm appropriate foundation materials and cleanliness prior to pouring concrete.
If any soil conditions encountered during construction are found to differ from those noted above, Tectonic
must be notified immediately and an inspection carried out to determine if changes to footing design are
required.

4.4   Drainage
Adequate site drainage must be installed to ensure that surface water flows are controlled, and diverted
away from the building area and batters. Flows must not be allowed to form concentrated streams running
across the building platform, adjacent batter slopes or over top retaining walls. Lined (with turf, rock,
concrete, or similar) cut off/diversion drains should be constructed along the crests and toes of the existing
batters and directed via lined batter chute drains or pipes to discharge at least 5 m down slope of any




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

 

4.3 Footing Design

Footings for the proposed shed and any ancillary structures (e.g. tanks or retaining walls) should penetrate
through any fill, and residual soils, to found a minimum of 0.3 m into very low strength (or stronger) rock.
Footings so founded may be designed using an allowable bearing pressure of 400 kPa. It is understood that
the shed slab and footings will found directly on/into such rock.

Footing design should also account for potential soil reactivity, to be assessed by others.

All footings should found such that they are not adversely affected by any adjacent excavations, trenches, or
retaining walls that are not designed to support building loads. Footings should found at least below a plane
extending 1 m horizontally from the base of trenches/excavations/retaining walls, then rising up at 1V:1H, as
illustrated in Text Figure 12.

TRENCH BACKFILL
GROUND LEVEL /

 

aS

   

a
TRENCH SIDEWALL ~

 

7 — \FOUND F
ie BELOW THIS UNE

 

 

 

SEWER / STORMWATER PIPE

 

 

 

 

 

 

 

 

RETAINING WALL

Text Figure 12: Footing depth required to prevent undermining or surcharge loading

Footing bases must be cleaned following mechanical excavation to expose undisturbed materials over the
full base area. A suitably qualified and experienced RPEQ engineer must inspect the footing excavations to
confirm appropriate foundation materials and cleanliness prior to pouring concrete.

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

4.4 Drainage

Adequate site drainage must be installed to ensure that surface water flows are controlled, and diverted
away from the building area and batters. Flows must not be allowed to form concentrated streams running
across the building platform, adjacent batter slopes or over top retaining walls. Lined (with turf, rock,
concrete, or similar) cut off/diversion drains should be constructed along the crests and toes of the existing
batters and directed via lined batter chute drains or pipes to discharge at least 5 m down slope of any

 

tectenic

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