excavation & trench safety - pncwa.memberclicks.net file• soils are classified by osha into...
TRANSCRIPT
EXCAVATION & TRENCH SAFETY
BY John T. Shawcroft
TRENCH COLLAPSE HAZARDS
• Four types to be aware of:– 1. Spoil Pile Slide– 2. Shear Wall Collapse– 3. Belly Slough– 4. Lip Slide
Spoil Pile Slide 8 ft. trench
Belly Slough 8 ft. trench
Shear Wall Collapse 8 ft. trench
Lip Slide 8 ft. trench
RESCUES
• Facts and figures
Trench Rescue
Trench Rescue in Progress
Classification of Soil Types
• Soils are classified by OSHA into three types:
» 1. Group A - clay, hardpan, and caliche » 2. Group B – loam, sandy loam, silt, silty loam &
angular gravel» 3. Group C – sand and other “running” types of
soil
• Soils can and do shift from one type to another as the environment acts upon it.
Access Ladder with Shoring
Ladder in Trench
What’s Wrong?
Inspection
• Daily inspection of excavation and adjacent areas by a competent person prior to start of work each shift and as needed throughout the shift.
• Inspections must be made after each rain storm or other hazard-increasing event.
OSHA QUICK CARD
Type A Soil
Soil Type B
Type C Soils
Simple Bench for Type A Soils
Adjustable Shielding Strut
Access Ladder with Shoring
Credits• National Institute for Occupational Safety &
Health Spokane Research Laboratory – Trench Safety Awareness
• Excavation/ Trenching Safety – Veolia Water EHS&S
• 29 CFR 1926.652 Safety Rules• Texas Trial Lawyer: Trench Collapse Accidents
& Excavation Cave-in Injuries & DeathsWillis Law Firm1221 McKinney; Suite 3333Houston, TX