Shorings
A protective system must be in place at this depth before workers are permitted to enter the trench.
1.2 m / 3.93 ft
Soil that is very stiff and dense, has medium internal strength, appears damp after excavation, and can be penetrated with moderate difficulty is classified as what soil type?
Type 2 soil
Where must ladders be positioned in relation to the excavation support system?
Within the protected area
These people onsite must review locates and confirm it matches marks on ground
Who is EVERYONE? (Crew, hydrovac operator, mechanical operator, Supervisor)
The minimum distance any tools, debris, material, or dirt piles must be placed away from an excavation edge.
What is 1 meter?
As a trench gets deeper, what must be done with trench boxes to keep workers protected?
They must be stacked on top of each other
Soil that shows surface cracking, water seepage, may cave in to a natural 45° slope when dry, or slab off when wet, is classified as what soil type?
Type 3 soil
This is the maximum distance a ladder can be from any worker in a trench to ensure safe egress.
7.5 m / 24.6 ft
These are the excavation methods you must use when digging within 1.2m of underground utilities.
hydrovac and hand digging
These two activities must never be performed while a worker is inside a trench, as they can lead to sudden collapse, engulfment, or struckby.
Adjusting/installing/removing shoring, and backfilling.
Protective systems for excavations deeper than what depth must be designed and approved by a professional engineer?
More than 6 m / 20 ft
Soil that has almost no internal strength, especially when wet or muddy, and is sensitive to vibration, is classified as what soil type?
Type 4 soil
This is how far a ladder must extend above the landing area in an excavation to ensure safe access and exit.
900 millimetres / 35 inches / 3 ft
This is the minimum distance you must maintain from an UNEXPOSED utility when using mechanical excavation equipment.
1.2 meters
This designated person must always be present when a worker enters a trench, acting as a safety watch and communicating with workers below. What is this person called?
A topman.
Supports must be installed at intervals no greater than how many metres, unless an engineer specifies otherwise?
1.5 metres / 4.9 ft
For Type 2 or 3 soil, what is the required slope ratio? (if you choose to slope)
1:1 (45 degrees). Equates to a 1 meter horizontal distance for every 1 meter of vertical rise
The minimum height a support system, such as shoring or a trench box, must extend above the top edge of an excavation, unless engineer drawings say otherwise?
0.3 metres / 0.9 ft / 11.8 inches
This is the minimum distance you must maintain from an EXPOSED utility when using mechanical excavation equipment.
0.3 meters
Spotters are mandatory when (give 3 major situations)
Reversing, Operating near underground utilities, operating near overhead utilities, around tree protection zones, in tight workspaces
Shoring boxes must be installed how close to the bottom of the trench, unless the manufacturer or engineer specifies otherwise?
No more than 1 foot gap / 0.3 m
For Type 4 soil, what slope ratio is required? (if you choose to slope)
1:3. Equates to a 3 meter horizontal distance for every 1 meter of vertical rise
Excavations exceeding this depth must be protected with a barrier or guardrail at least 1.1 meters (3.6 feet) high to prevent falls.
What is 2.4 meters or 7.9 feet?
Name 5 situations where work must be stopped immediately and the Utilities Coordinator (Jessica) must be notified for relocates.
-The drawing does not match the written locate area
-A utility shown on the locates is not found
-A utility is found outside the 1 m tolerance zone
-A utility is found but is not shown on the locates
-The utility found does not match the locate description (material, size, or service)
Under Rabcon’s rules, which soil types do we never classify soil as (to take the most precaution)?
Type 1 or Type 2