Which is a major hazard that can occur in trench excavations?

Cave-ins are a major hazard that can occur in trench excavations because they pose a significant risk to workers who are operating within those trenches. Trench cave-ins happen when the walls of the excavation collapse, which can happen suddenly and without warning, leading to potentially fatal situations for anyone inside. The risk of cave-ins is influenced by several factors, including the depth of the trench, the type of soil, and the method of excavation. It is crucial for workers to implement safety measures, such as sloping or shoring the sides of trenches, to prevent these dangerous occurrences and ensure worker safety.

While water infiltration, excessive noise, and vibration from machinery can present hazards at worksites, they are generally considered less immediate threats compared to the risk of cave-ins in trench scenarios. Water infiltration can lead to softening of the soil and increased likelihood of cave-ins, while excessive noise and vibration primarily have implications for worker comfort and long-term exposure, rather than posing an immediate physical threat in the same way that a cave-in does.