Shoring is the system called that supports the sides of an excavation.
Also known as a trench box or trench shield, a shield is a structure that protects the worker by being able to withstand the forces imposed on it by a cave-in. A structure that supports the sides of an excavation to prevent a cave-in.
Also, which of the following is an excavation hazard? The hazards and risks are usually: People and vehicles falling into the excavation. The undermining of nearby structures causing their collapse into the excavation. Damage to underground services during excavation work causing electrocution, explosion, gas escape, flooding etc. Ingress of water causing flooding.
Keeping this in consideration, what supports the side of an excavation?
Shoring. A structure that supports the sides of an excavation and protects against cave-ins.
When should a competent person do inspections?
A competent person must inspect excavations:At least once in every day during which persons are at work there. If more than 2 metres deep, at the start of each shift before work begins. After any event likely to have affected the strength or stability of the excavation or the shoring.
How can you control water around an excavation?
There are number of techniques by which ground water exclusion are obtained: Forming impervious barriers by grouting with cement, clay suspension. Chemical consolidation for controlling ground water in excavation. Ground water control by compressed air. Freezing ground water control.
What is Type C soil?
Type C soil is the least stable type of soil. Type C includes granular soils in which particles don’t stick together and cohesive soils with a low unconfined compressive strength; 0.5 tons per square foot or less. Examples of Type C soil include gravel, and sand. Clumps mean that the soil is cohesive.
Which of the following is the greatest risk of an excavation?
Cave-ins pose the greatest risk and are much more likely than other excavationrelated accidents to result in worker fatalities. Other potential hazards include falls, falling loads, hazardous atmospheres, and incidents involving mobile equipment.
Is fire an excavation hazard?
Flammable/Combustible/Explosive Atmospheres: Volatile organic compounds found in petroleum products can move through small spaces in soils and accumulate in excavations. This can create both a fire and toxic hazard. Buried tanks next to an excavation site are a common source of these compounds.
Which of the following ways to avoid excavation hazards was mentioned in the construction?
How Do I Avoid Hazards? Provide stairways, ladders, ramps, or other safe means of egress in all trenches that are 4 feet deep or more. Position means of egress within 25 lateral feet of workers. Structural ramps that are used solely for access or egress from excavations must be designed by a competent person.
What is the term for soil removed from an excavation?
Earth excavation This involves the removal of the layer of soil directly beneath the topsoil. The removed material (referred to as ‘spoil’) is often stockpiled and used to construct embankments and foundations.
What types of braces are used in shoring systems?
Shoring or shielding is used when the location or depth of the cut makes sloping back to the maximum allowable slope impractical. Shoring systems consist of posts, wales, struts, and sheeting. There are two basic types of shoring, timber and aluminum hydraulic.
What type of soil Cannot be benched?
Type C soil is cohesive with an unconfined compressive strength of 0.5 tsf or less. Examples include granular soils such as gravel, sand and loamy sand; submerged soil or soil from which water is freely seeping; and submerged rock that is not stable. Benching Type C soil is unacceptable and shall not be done.
What is the difference between excavation and trenching?
The Difference Defined According to OSHA, an excavation is a cavity in the surface of the ground created by deliberate human action that removes earth. Excavating is the act of digging a hole in the ground, says OSHA, while trenching is the act of digging an elongated narrow excavation.
What is shoring in excavation?
From Wikipedia, the free encyclopedia. Shoring is the process of temporarily supporting a building, vessel, structure, or trench with shores (props) when in danger of collapse or during repairs or alterations. Shoring comes from shore, a timber or metal prop. Shoring may be vertical, angled, or horizontal.
What is benching in excavation?
Benching (Benching system) means a method of protecting employees from cave-ins by excavating the sides of an excavation to form one or a series of horizontal levels or steps, usually with vertical or near-vertical surfaces between levels.
What can cause excavations to collapse?
Workers can be killed or seriously injured if the sides of a trench or other excavation collapse. Cave-ins are most often caused by: Vibration from construction equipment or traffic in the construction area that makes the soil come apart. The weight of equipment that is too close to the edge of the trench.
Is an excavation considered a confined space?
In general practice, all trench excavations over four feet in depth should be considered confined spaces until a competent person has ruled out all of the potential hazards associated with it.