Occupational Health and Safety Code

The Occupational Health and Safety Code provides specific technical health and safety rules and requirements for Alberta workplaces.

Alberta Regulation 191/2021

Schedule 9 Shoring Component Dimensions

Contents

 

Shoring components used in excavations, trenches, tunnels and underground shafts

[ See subsections 457(1), 457(2) ]

 

 

Uprights

Stringers

Cross‑braces



Soil type



Depth of excavation
(metres)



Minimum dimensions
(millimetres)


Maximum horizontal spacing
(millimetres)



Minimum dimensions
(millimetres)


Maximum vertical spacing
(millimetres)

Minimum dimensions
(millimetres)

Maximum spacing
(millimetres)

Width of trench



Vertical



Horizontal

Less than
1.8 metres

1.8 to
3.7 metres


Hard
and
compact

1.5 to 3.0

38 x 235

1800

89 x 140

1200

89 x 89

140 x 140

1200

1800

More than
3.0 to 4.5

 

38 x 235

 

1200

 

89 x 140

 

1200

 

89 x 140

 

140 x 140

 

1200

 

1800

More than
4.5 to 6.0

 

38 x 235

 

10

 

140 x 140

 

1200

 

140 x 184

 

140 x 184

 

1200


1800

Likely
to crack
or
crumble

1.5 to 3.0

38 x 235

1200

89 x 140

1200

89 x 140

140 x 140

1200

1800

More than
3.0 to 4.5

 

38 x 235

 

900

 

140 x 140

 

1200

 

140 x 140

 

140 x 184

 

1200

 

1800

More than
4.5 to 6.0

 

38 x 235

 

10

 

140 x 184

 

1200

 

140 x 184

 

140 x 184

 

1200

 

1800

Soft,
sandy
or
loose

1.5 to 3.0

38 x 235

10

140 x 140

1200

140 x 140

140 x 184

1200

1800

More than
3.0 to 4.5

 

38 x 235

 

10

 

140 x 184

 

1200

 

140 x 184

 

184 x 184

 

1200

 

1800

More than
4.5 to 6.0

 

38 x 235

 

10

 

184 x 184

 

1200

 

140 x 184

 

184 x 235

 

1200

 

1800