What are the four main hazards that cause cave-ins to occur?

falls

falls are the leading cause of all construction worker deaths. in 2014, they accounted for 348 of the 874 fatalities in construction. looking at the most cited osha standards violations for the construction industry in fiscal year 2015 (october 2014 – september 2015) and it’s no surprise that falls were the cause of nearly 40% of all construction worker deaths.

six of the top 10 most frequently cited violations deal with protecting workers from fall hazards. the top four have consistently been the most cited standards for the past several years. they are:

standard number: 1926.501 – duty to have fall protection.

standard number: 1926.451 – general requirements for scaffolds.

standard number: 1926.1053 – ladders.

standard number: 1926.503 – training requirements for fall protection.

the other two that made the top 10 were standard number: 1926.453 – aerial lifts and standard number 1926.502 – fall protection systems criteria and practices at no. 9 and no. 10, respectively.

in construction, fall protection is required for all employees working at a height of six feet or more above a lower level. it is also required when working at any height directly above dangerous machinery or equipment, including impalement hazards such as rebar. there are exceptions to this rule. when working on scaffolds the height for requiring fall protection is 10 feet.

osha has outlined three prescribed methods of providing fall protection to workers: guardrails, personal fall arrest systems and safety nets. of the three, guardrails are the only method that actually prevents falls. the other two methods are designed to prevent a worker who has fallen from coming into contact with a lower level.

guardrails are typically used on unprotected edges, scaffolds and around openings such as skylights and elevator shafts. the top edge of guardrail systems should be 42 inches (+/- 3 inches) from the walking or working surface. the top rail should be able to withstand 200 pounds of force and the middle rail should be able to withstand 150 pounds of force to prevent falls.

personal fall arrest systems are made up of three main components: full-body harness, connecting device and anchorage. the minimum breaking strength for connectors, d-rings and snaphooks, and vertical lifelines and lanyards that make up the connecting device is 5,000 pounds for each component. personal fall arrest systems should prevent a worker from falling any further than six feet and should prevent the worker from making contact with a lower level. personal fall arrest systems should be inspected before each use and after any fall to ensure they are free of any damage and in proper working order.

explanation:

i believe the answer would have to be a dependable person