Excavation and Trenching
Introduction
Two workers are killed every month in trench collapses. An excavation is any man-made cut, cavity, trench, or depression in an earth surface formed by earth removal.
Trench (Trench excavation) means a narrow excavation (in relation to its length) made below the surface of the ground. In general, the depth is greater than the width, but the width of a trench (measured at the bottom) is not greater than 15 feet (4.6 meters).
Dangers of Trenching and Excavation
Cave-ins pose the greatest risk and are much more likely than other excavation-related accidents to result in worker fatalities.
Trench Cave-In
Other potential hazards in trenches include falls, falling loads, hazardous atmospheres, and incidents involving mobile equipment. If you were to be buried by one cubic yard of soil, the weight a car would be pressing down on you.
An unprotected trench is an early grave. Do not enter an unprotected trench.
In 2022, a 17-year-old worker suffered fatal injuries after being struck in the head by a large chunk of asphalt, and a company foreman was injured that same year when an unprotected section of excavation wall caved-in. The employees were working for a contractor on a residential sewer connection.
After an investigation, OSHA issued a serious citation and financial penalty to the contractor for its violation of federal law. Several years later, having failed to take adequate measures to protect its employees, the contractor faces over $200,000 in proposed penalties.
Trenching standards require protective systems on trenches deeper than 5 feet, and soil and other materials kept at least 2 feet from the edge of a trench. Additionally, trenches must be inspected by a knowledgeable person, be free of standing water and atmospheric hazards and have a safe means of entering and exiting prior to allowing a worker to enter.
Knowledge Check Choose the best answer for the question.
5-1. What poses the greatest risk to workers at an excavation site?
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