ABSTRACT
Investigations of trenching and excavation mishaps have shown that little heed was paid by excavators to the hazards involved with excavating and trenching. During audits of various plant excavation programs, it is not unusual to find a weak link in the program. Trenches and excavations can be full of additional obstacles; for example, carelessly placed tools and equipment or excavated material can cause injuries due to slips, trips, or falls. One of the danger signs to look for in trenching or excavation work is surface cracking. Failure of an overloaded foundation, collapse of the sides of an excavation, or slope failure on the sides of a dike, hill, or similar feature is termed structural failure. Sloping or benching is excavation protective measures that cut the walls of an excavation back at an angle to its floor. Shoring and shielding are two protective measures that add support structure to an existing excavation.
