WELCOME

1. TRENCHING AND SHORING SAFETY CORPORATE SAFETY TRAINING 29 CFR 1926.650-653 WELCOME

2. COURSE OBJECTIVES • Introduce The Trenching & Shoring Safety Program • Establish The Programs Role. • Discuss the components of an effective program. • Introduce ideas to help develop an effective program. • Introduce Basic Skills in the Recognition & Control of Trenching & Shoring Hazards.

3. APPLICABLE REGULATIONS • 29 CFR 1926.650 - General Protection Requirements • 29 CFR 1926.651 - Specific Excavation Requirements • 29 CFR 1926.652 - Specific Trenching Requirements • 29 CFR 1926.653 - Definitions • Appendix - A - Excavations • Appendix - B - Sloping and Benching • Appendix - C - Timber Shoring for Trenches • Appendix - D - Aluminum Hydraulic Shoring

4. BASIS FOR THE REGULATIONS • Hundreds of workers killed annually from cave-ins • Thousand of workers injured annually from cave-ins • Fatality rate for trenching is twice the level for general • construction

5. PURPOSE OF THE PROGRAM REASONS TO MAINTAIN AN EFFECTIVE PROGRAM: • Peace of mind • Reduced liability • Increased productivity • Reduced lost man-hours • Improved employee morale • Reduced or eliminated fines • Improved health of employees • Reduced injury and illness rates • Lower workers’ compensation costs • Because it’s the right thing to do!!!!!!

6. MECHANISM OF DEATH • Asphyxiation • Each time a breath is exhaled the weight of the load restricts inhalation of the next breath. Slow suffocation usually follows unless rescue is immediate.

7. DYNAMIC SITE CONDITIONS • CAVE-INS RESULT FROM: • Vibrations • Adjacent Structures • Freezing and Thawing • The Weight of the Soil Itself • Addition or Removal of Water • Reduction in Frictional and Cohesive Capacities of Soil

8. 3 FEET 1 FOOT 100lbs or more 3000lbs or more HOW MUCH DOES SOIL WEIGH? • DEPENDING ON THE DENSITY AND WATER CONTENT: • One cubic yard weighs - 3000lbs or more • One cubic foot weighs - 100lbs or more

9. HOW DO MOST DEATHS OCCUR? • Instantaneously • Trenches 5 to 15 deep • With absolutely no warning • In seemingly safe conditions • With workers in a bent or lying position

10. SITE EVALUATION • BEFORE YOU BEGIN EXCAVATION: • The site must be assessed • Potential hazards must be determined • Known hazards reduced or eliminated • Emergency procedures established • Periodic inspection intervals determined • Utility locations must be staked or marked

11. BASIC SAFETY REQUIREMENTS • Conduct inspections before each work shift • Do not travel under elevated loads • Do not work over unprotected employees • Wear proper personal protective equipment • Provide walkways or bridges over trenches • Provide trench exits within 25 feet of workers in • trenches more than four feet deep • Ensure spoilage is at least 2 ft. from trench edges

12. EMERGENCY PROCEDURES • Immediately call 911, or the Emergency Response Team • Report: - Exact Location • - Number of Victims • - Nature of Emergency • - Trench Measurements • - Special Hazards • Keep all life-support and dewatering systems operating • Clear workers away from the excavation • Shut down heavy equipment • Be prepared to meet and brief rescue personnel

13. EMERGENCY PROCEDURES Continued • What not to do: - Don’t Panic! • - Control would-be rescuers • - Don’t sacrifice anyone else • - Never attempt to dig someone out • using motorized equipment • Remember - Your actions could save a life!

14. FOOT AND VEHICLE TRAFFIC • ACCIDENT PREVENTION METHODS: • Warn and reroute public traffic • Post signs, barricades and flagmen • Mandate use of reflective vests • Warn site traffic with stoplogs etc. • Install protective supports systems

15. SURFACE ENCUMBRANCES • MUST BE: • Removed • Relocated • Supported to protect site personnel • EXAMPLES INCLUDE: • Fencing • Posts • Telephone • Cable • Electrical Access Boxes

16. UNDERGROUND INSTALLATIONS • Utility lines must be located before excavating begins • Utility companies or owners must be contacted: • -- Response times must be considered • -- Advised of the proposed work • -- Questioned concerning underground installations • need to be answered

17. UNDERGROUND INSTALLATIONS Continued • If no response is given within 24 hours* work can • cautiously proceed *(local timeframes may vary) • Underground installations must be determined by • safe and acceptable means • Excavated underground installations must be • protected • Never under estimate hazards associated with • underground utilities!!!

18. STRUCTURAL RAMPS: USED ONLY BY PEOPLE DESIGNED BY A “COMPETENT PERSON” EGRESS REQUIRED EVERY 25 FEET (LATERAL) > = 4FT ACCESS AND EGRESS

19. TRENCH SAFETY • TRENCHES MORE THAN 5 FEET: • Require shoring • Or must have a stabilized slope • IN HAZARDOUS SOIL CONDITIONS: • Trenches under 5 feet need protection

20. BACK-UP FALL PROTECTION TIE-OFF POINT WINCH SAFELINE TRIPOD SAFELINE HAZARDOUS ATMOSPHERES • TESTING AND CONTROLS: • Oxygen deficiency • Flammable atmospheres • Testing • EMERGENCY RESCUE EQUIPMENT: • Availability • Lifelines

21. Adequate Precautions Must Be Taken When Working in Accumulated Water Controlling Water and Water Removal Must Be Monitored by a Competent Person Ditches, Dikes or Comparable Means Should Be Used to Prevent Surface Water From Entering Excavations HAZARDS & WATER ACCUMULATION

22. Don’t under estimate the effects weather can have Weather can have a drastic effect on the site Daily (or hourly) site inspections must be made Consider protection from: WEATHER FACTORS • Lightning • Flooding • Erosion • High winds • Hot or Cold Temperatures

23. When stability is endangered support systems must be used. Excavation below the base of a foundation will not be permitted when it poses a hazard except when: A support system is provided The excavation is in stable rock A registered professional has approved the site or deemed the situation will not pose a hazard STABILITY OF ADJACENT STRUCTURES

24. Daily inspections must be made by a competent person of: When evidence is found of a hazardous condition, the exposed employees must be Immediately removed from the area. SITE INSPECTIONS • Excavations • Adjacent areas • Protective systems

25. Guardrails must be provided for crossing over excavations Barriers must be provided for remotely located excavations FALL PROTECTION

26. TYPE A SOILS - Clay - Silty Clay - Sandy Clay - Clay Loam TYPE B SOILS - Granular Cohesionless Soils (Silt Loam) TYPE C SOILS - Gravel - Sand - Loamy Sand SOIL CLASSIFICATION SYSTEM

27. SOIL CLASSIFICATION MUST BE DONE BY A COMPETENT PERSON: A B C SOIL CLASSIFICATION SYSTEM Continued • VISUAL TEST • Check entire worksite • Fissured ground • Layered soil • Disturbed earth • Seepage • Vibration • Poor drainage

28. A B C SOIL CLASSIFICATION SYSTEM Continued • MANUAL TEST • Plasticity • Dry Strength • Thumb penetration • Pocket penetrameter • Hand operated shear vane • WARNING: One soil inspection and classification may not be enough. Outside disturbances during excavation may change even the best soil classification. Inspect the soil after any change in conditions.

29. Are cohesive soils with an unconfined, compressive strength of 1.5 t/sf. Clues that soil is not type A: If it is fissured If it is subject to vibration If it has been previously disturbed If the soil is part of a sloped, layered system If the material is subject to other factors that would require it to be classified as a less than stable material A B C TYPE A SOILS

30. Are cohesive soils with an unconfined compressive strength greater than 0.5 t/sf Types include angular gravel, silt, silt loam, sandy loam and silty clay loam Previously disturbed soils except those which would be classified as type C Dry rock that is not stable A B C TYPE B SOILS

31. Are cohesive soil with an unconfined compressive strength of .5 t/sf Are granular soils including gravel, sand, and loamy sand Submerged soil or soil from which water is seeping Submerged rock that is not stable A B C TYPE C SOILS

32. Each employee must be protected from cave-ins by an adequately designed system. Exceptions are: Excavations made in stable rock Excavations less than 5 feet Protective systems must have the capacity to resist all loads that are expected to be applied to the system REQUIREMENTS FOR PROTECTIVE SYSTEMS

33. DESIGN OF BENCHING AND SLOPING SYSTEMS: OPTION 1 - Allowable configurations and slopes OPTION 2 - Determination of slopes and configurations using 29 CFR 1926.652 OPTION 3 - Designs using other tabulated data OPTION 4 - Design by a registered professional engineer REQUIREMENTS FOR PROTECTIVE SYSTEMS Continued

34. Must be free from damage or defects that might impair proper function Must be used and maintained in a manner that is consistent with the recommendations of the manufacturer Must be examined by a competent person if damage occurs MATERIALS AND EQUIPMENT

35. GENERAL REQUIREMENTS INSTALLATION AND REMOVAL OF SUPPORT • Support systems must be securely connected • Support systems must be installed and removed in a manner that protects from collapse • Support systems must not be subjected to loads exceeding design specifications

36. GENERAL REQUIREMENTS INSTALLATION AND REMOVAL OF SUPPORT Continued • Additional precautions must be taken to ensure safety before temporary removal begins • Removal must begin at the bottom of the excavation • Backfilling must progress together with the removal of support systems from excavations

37. EMPLOYEES MUST NOT BE PERMITTED TO WORK: SLOPING AND BENCHING SYSTEMS • On the faces of sloped or benched excavations • At levels above other employees except when employees at the lower levels are adequately protected from the hazard of falling, rolling or sliding material or equipment

38. TEMPORARY SPOIL PILES: 2 FEET MINIMUM SLOPING AND BENCHING SYSTEMS Continued

39. SLOPING GENERAL REQUIREMENTS SLOPING AND BENCHING SYSTEMS Continued • Various slope angles are allowed by OSHA • Appendix B to 1926 Subpart P must be consulted • Evacuate the excavation if walls show signs of distress • If soil conditions change, re-inspect.

40. BENCHING GENERAL REQUIREMENTS SLOPING AND BENCHING SYSTEMS Continued • Various slope angles are allowed by OSHA • Appendix B to 1926 Subpart P must be consulted • Evacuate the excavation if walls show signs of distress • If soil conditions change, re-inspect.

41. 90 Degrees 53 Degrees Maximum TYPE A STABLE ROCK 34 Degrees Maximum 45 Degrees Maximum TYPE C TYPE B SLOPING AND BENCHING SYSTEMS Continued

42. TYPE A SOILS 20 FEET MAX 1 3/4 BENCHING EXAMPLE

43. TYPE B SOILS 20 FEET MAX 1 1 SLOPING EXAMPLE

44. JACKS/CROSSBRACES SHEETING WALES SHORING SYSTEMS

45. GENERAL SHORING SYSTEMS Continued • Shoring provides a framework to work in • Shoring uses wales crossbraces and uprights • Shoring supports excavation walls • OSHA TABLES PROVIDE SHORING DATA • Soil type must be known • Depth and width of the excavation must be known • You must be familiar with the OSHA Tables

46. REMOVAL JACKS/CROSSBRACES SHEETING WALES SHORING SYSTEMS Continued • Remove shoring from the bottom up • Pull sheeting out from above • Backfill immediately after removal of support system

47. SHORING SYSTEMS Continued PNEUMATIC/ HYDRAULIC JACKS SCREW JACK

48. GENERAL SHIELD SYSTEMS • Shield systems must project at least 18 inches above the lowest point where the excavation face begins to slope At Least 18 Inches

49. GENERAL SHIELD SYSTEMS Continued • Shield systems must not be subjected to loads exceeding those which the system was designed to withstand • Shields must be installed to restrict hazardous movement • Employees must be protected from the hazard of cave-ins when entering or exiting the areas protected by shields • Employees must not be allowed in shields when shields are being installed, removed, or moved vertically

50. SHIELD SYSTEMS Continued COMMON TRENCH SHIELD