At what depth must an excavation be supported UK?
What is the 1.2 metres rule? In older UK health and safety regulations, it stated that any trench that was 1.2 metres depth, or above, should have trench support.
How deep can an excavation be without shoring UK?
If you’re figuring out when to use a trench box- if an excavation is more than 5 feet, or 1.5 metres deep, then shoring equipment is needed by legal requirement.
When should an excavation be supported?
What you need to do. The law says you must prevent danger to workers in or near excavations. To maintain the required precautions, a competent person must inspect excavation supports or battering at the start of the working shift and at other specified times. No work should take place until the excavation is safe.
What is the maximum depth a trench can be dug without support?
The basis of the rule is that, if a trench is under 1.2m deep, then people can enter the trench without the sides of the excavation being supported or battered back. This rule is no longer something that should be considered. 1.2m is no longer the threshold for the need to support an excavation.
What methods are used for supporting trenches?
Trench sheets are the most adaptable of the systems available, and are most commonly used to retain poorer soil. They can support deeper trenches with larger surcharges and provide a continuous support.
What depth is considered a trench?
A trench is defined as a narrow excavation (in relation to its length) made below the surface of the ground. In general, the depth of a trench is greater than its width, but the width of a trench (measured at the bottom) is not greater than 15 feet (4.6 m). What are the dangers of trenching and excavation operations?
What two requirements must be met so that a trench does not need to have a protective system installed?
The standard does not require the installation and use of a protective system when an excavation (1) is made entirely in stable rock, or (2) is less than 5 feet deep and a competent person has examined the ground and found no indication of a potential cave-in.
What is the typical point of failure in an excavation?
What is the typical point of failure in an excavation? Soil failure is defined as the collapse of part or all of an excavation wall. The most common soil failure is typically described as an unexpected settlement, or cave-in, of an excavation. Soil sliding is the most common factor leading to soil failure.
What is most likely to cause an excavation to collapse?
Excavated spoil, plant or materials should not be stored close to the sides of excavations as loose material can fall in. The extra loading can make the sides of the excavation more likely to collapse. Prevent people from falling into excavations by substantial barriers around the edges.
When should excavations be supported?
How can you prevent excavation from collapsing?
The sides of the excavation or trench should be supported by timbering or other suitable means or sloped and battered back to a safe angle of repose to prevent a collapse.
What are 3 causes of trench collapse?
Handling and placing pipe and other materials • Being struck by moving equipment • Falls as workers climb in or out of an excavation • Falling over equipment or excavated material • Falling into the trench • Exposure to toxic, irritating, or flammable gases.
What is a way to stabilize a trench so it won’t collapse?
Sloping the walls is one way to keep a trench from collapsing. The angle of the slope depends on soil conditions. • Type 1 and 2 soils: Cut trench walls back at an. angle of 1-to-1 or 45°. That’s 1 m (3 ft) back for each 1 m up.
Do Trench Boxes support trench walls?
Trench boxes can be used to protect workers in cases of cave-ins, but not to shore up or support trench walls. They can support trench walls if the space between the box and the trench wall is backfilled with soil and compacted properly.
What are the safety precautions for trenching?
Keep excavated soil (spoils) and other materials at least 2 feet (0.61 meters) from trench edges. Keep heavy equipment away from trench edges. Identify any equipment or activities that could affect trench stability. Test for atmospheric hazards such as low oxygen, hazardous fumes, and toxic gases when workers are more than 4 feet deep.
What is the definition of a trench excavation?
A trench is an excavation in which the depth exceeds (is bigger than) the width. What are the hazards associated with trenching and excavation? Working in trenches and excavations is hazardous to both the workers who work inside them, and to workers on the surface.
How do you prevent spoils from falling down in a trench?
Use retaining devices, such as a trench box that will extend above the top of the trench to prevent equipment and spoils from falling back into the excavation. Where the site does not permit a 2-foot setback, spoils may need to be temporarily hauled to another location.