All Actual Answers.
OSHA - Answer Occupational Safety and Health Administration
OSHA is the main - Answer federal agency charged with the enforcement of safety and health
legislation
Mission: - Answer to" assure safe and healthful working conditions for working men and
women by setting and enforcing standards and by providing training, outreach, education and
assistance"
Title 29 refers to - Answer the Labor title for the code of federal regulations (CFR)
construction is covered in - Answer part 1926
the excavation regulations are found in - Answer subpart P and in Sections 650-652
clarification about a regulation may be - Answer sought by writing to OSHA
scope of standard - Answer excavation standard applies to all open excavations made in the
earths surfaces including trenches, all surface encumbrances that would create a hazard, and
protective systems
What in the standard? - Answer - scope, application & definitions
- specific excavation requirements
- requirements for protective systems
-appendixes that detail:
-- soil classification
-- sloping & benching
-- timber & aluminum hydraulic shoring
-- protective system selection decision tree
definitions 1926.650 - Answer accepted engineering practices
aluminum hydraulic shoring
bell-bottom pier hole
,benching
cave in
cross braces (kickout)
excavation
faces or sides
failure
hazardous atmosphere
kickout
protective system
ramp
registered professional engineer
sheeting
shield
Definitions - Answer shoring
sloping
stable rock
structural ramp
support systems
tabulated data
trench
uprights
wales
Excavation - Answer any man made cut, cavity, trench or depression in an earth surface
formed by earth removal
- Ex: excavation for building foundations, utilities, highways, etc.
trench excavation - Answer a narrow underground excavation with a depth greater than the
width but no wider than 15ft
competent person - Answer one who is capable of identifying existing and predictable
hazards in the surrounding, or working conditions which are unsanitary, hazardous, or
dangerous to employees, and who has authorization to take prompt corrective measures to
eliminate them
, qualified person - Answer one who, by possession of a recognized degree, certificate, or
professional training, and experience, has successfully demonstrated his ability to solve or
resolve problems relating to the subject matter, the work, or the project
Registered professional engineer (RPE) - Answer one who is registered as a professional
engineer in the state where the work is to be performed. A professional engineer, registered in
any state is deemed to be a 'RPE' within the meaning of this standard when approving designs
for 'manufactured protective systems' or tabulated date to be using in interstate commerce
tabulated data - Answer tables and charts approved by a registered professional engineer
and used to design and construct a protective system. The tabulated date for protective systems
must be made available on the job site
Cave-In - Answer -seperation of a mass of soil from the side of an excavation or
-loss of soil from under a trench shield or support system and its sudden movement into the
excavation
-could entrap, bury, injure or immobilize a person
cave -in cont. - Answer -soil is a very heavy material:
-- a cubic foot can weigh 114lbs
-- a cubic yard can be as heavy as a car
-assume a unit weight of 114lbs/ft^3
-y=W/V
- W =114X27X1(1yd^3) = 3078lbs
-average car or light-duty truck in the US weighs 4000 lbs
Cave-In cont.. - Answer -undisturbed soil is similar to a number of columns supporting each
other
-when an excavation is performed, the soil self-support is disturbed
- cracks start to form from the edge of the excavation (~1/2 depth of excavation)
- no lateral support is present to prevent failure
mechanism of a cave-in - Answer failure starts with zone A, then B, and then C
most common causes of cave-ins - Answer -poor planning
-misjudgment of soil type
-inadequate, or incorrect installation of protective devices
-defective protective devices