Excavation training module.pptx agar lbh

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1. BANYU URIP PROJECT EPC1 - Production Processing Facilities Contract No. C-3207067 Module 7 – Excavation CONSTRUCTION SAFETY TRAINING

2. Excavation 2

3. 1. Objectives Understand excavation hazards and risks Understand the forces at work in an excavation Name 5 OSHA requirements for excavations Describe the 3 general protective systems used in the construction of the excavation 3

4. 2. Excavation Hazards 4 In depth planning of all excavation activity is vital for project success. Principal hazards associated with excavation include: Risk of cave ins from loose soil or moving machinery near edge Vehicle traffic across excavation area Asphyxiation due to lack of oxygen Inhalation of toxic materials Falls Accidental severing of underground utilities (piping, elec., instrument) lines Access / egress for emergency response

5. 3. Excavation Cave-In Deaths Cave-ins are predictable and should be expected. The US numbers... 10,000 entrapments per year 1000-2000 lost time injuries per year 100-400 deaths per year 5

6. It’s just dirt. Right? A cubic foot of soil can weigh 50kg - 63kg or more (about the same as a small person) One cubic meter of soil can weigh more than 1300 kg which is as much as a small car, but it only occupies the area the size of an average office desk 6

7. 4. What is an excavation? An excavation is a cut in the earth’s surface But, it immediately begins to close due to a variety of forces . 7

8. What forces? The excavation WILL close (cave-in), the only question is when. How fast the cut closes depends mainly on two factors, soil type and the amount of moisture. 8 Pressure and downward forces Vibration Water table Weather, Ice, snow, rain Soil Type Moisture content Gravity Depth

9. 5. Soil Types Classification of soil and rock deposits shall be made by a competent person based on the results of at least one visual and at least one manual analysis. Test shall be conducted in accordance with local governing agency . 9 Rock Cemented soils Cohesive soils Granular soils Loams Most stable Least stable

10. 6. OSHA Requirements Protect Yourself Protective Systems Inspection by Competent Person Safe Access and Egress to all excavations General Trenching and Excavation Rules 10

11. 7. Protect Yourself Employers must instruct workers to recognize and avoid unsafe conditions associated with their work. Sides of trenches in unstable or soft material must be sloped, shored, shielded, or otherwise supported based on Type of soil Workers in trenches must wear personal protective equipment. 11

12. 8. Protective Systems Protective system must be either sloped, shored, or shielded to protect the workers. However………… Workers in a stooped or kneeling positions may require protection in shallow trenches 1,5 meter with bad soil. 12

13. 9. Sloping / Benching Trench sloping involves cutting back the trench walls to an appropriate maximum allowable slope. Soil conditions will determine the amount of material to be removed and at what angle the walls should be. 13 Remove Remove Angle Varies

14. 10. Sloping - Golden Pass Project 4Q07 14 Classic sloping / benching

15. 11. Shoring Shoring prevents the soil from caving in. The shoring of a trench can be accomplished with the use of wood timbers, screw jacks, hydraulic rams, or combinations of all of these methods. The soil conditions will determine the type and amount of shoring. 15

16. 12. Shielding Shields protect the workers inside the shields in the event of a cave-in. Shields do not prevent cave-ins Shield systems must be engineered for the specific situation 16 Trench Shields

17. 13. Inspection by Competent Person OSHA standards require that trenches be inspected daily and as conditions change by a competent person prior to worker entry A competent person is capable of identifying existing and predictable hazards or working conditions that are hazardous, unsanitary, or dangerous to employees and is authorized to take prompt corrective measures 17

18. 14. What means of access and egress are you required to provide? OSHA requires you to provide safe access and egress to all excavations, including ladders, steps, ramps, or other safe means of exit for employees working in trench excavation s 1.2 meters or deeper. These devices must be located in the excavation within 7.62 meters of all workers. Any structural ramps you use in your operation must be designed by a competent person if they are used for employee access or egress, or by a competent person qualified in structural design if they are used for vehicles. Also, structural members used for ramps or runways must be uniform in thickness and joined in a manner to prevent tripping or displacement. 18

19. 15. How can you protect workers against hazardous atmospheres inside excavations A competent person must test any excavation deeper than 1.2 meters) or where an oxygen deficiency or a hazardous atmosphere is present or could reasonably be expected , such as a landfill or where hazardous substances are stored nearby, before an employee enters it. If there are any hazardous conditions, you must provide the employee controls such as proper respiratory protection or ventilation. In addition, you are responsible for regularly testing all controls used to reduce atmospheric contaminants to acceptable levels. Any excavation / trenches more than 1.2 meter depth shall be considered as Confined space and safety precautions as per confined space entry procedure shall be followed. 19

20. 15. General Trenching and Excavation Rules Before beginning any excavation: Evaluate soil conditions (soil type, moisture, contamination,…) Evaluate excavation interferences with existing foundations and site traffic Design protective systems Identify and plan for undergrounds Especially critical for a Brownfield environment, allow sufficient time and resource to make sure that all undergrounds have been identified (Plant archives, drawings, field locators, hand probing,….), and mitigations measures are in place. Test for low oxygen, hazardous fumes, and toxic gases Provide safe in and out access Determine the safety equipment needed Evaluate need to implement a confined space entry process 20

21. 5. General Trenching and Excavation Rules During Excavation: Keep excavated materials at least 1 meter away from the edge Take additional precautions to prevent cave-ins for excavations subjected to vibrations from highway traffic Barricade to ensure unauthorized personnel and equipment do not enter the excavation Test the atmosphere prior to entry where there is a potential for oxygen deficiency hazardous fumes and toxic gases in any excavation greater than 1.2 meter in depth Set appropriate accesses and have appropriate emergency rescue equipment readily available 21

22. Recognize the Risk? 22 The trench wall collapsed burying the tester to approximately 1 meter of clay above his head

23. Excavation Summary Recognize the hazards around excavation sites… Soil type, moisture, traffic vibrations, existing foundations, underground utilities, ….. The 3 protective systems for excavations are: Slope or Bench the soil Shore the sides to prevent caving Shield the workers from a cave in 23

24. What’s wrong? 24

25. What’s wrong? 25

26. What’s wrong? 26

27. 27 Entry and exit point sealed off. Leaving workers at risk in case of emergencies. Poor shoring practice w/ scaffold poles & thin plywood Singapore Parallel Train IC&T C12A Trench

28. Point loading Signs of load pressure Singapore Parallel Train IC&T C12A Trench Poor shoring practice w/ scaffold poles & thin plywood

29. 29 After intervention, contractor admitted that work method they used not correct. Job was immediately stopped Singapore Parallel Train IC&T C12A Trench

30. 30 Condition after strong heavy rain on 1 st July 2009. Intervened with Contractor stopped work due to poor shoring practices, soil sluffing, poor access & dewatering Singapore Parallel Train SPT constructed on reclaimed sand with high water table

31. 31 Singapore Parallel Train IC&T C12A Trench Condition after strong heavy rain on 1 st July 2009. Poor shoring practices, soil sluffing, poor access & dewatering

32. 32 Singapore Parallel Train Condition after strong heavy rain on 1 st July 2009. Poor shoring practices, soil sluffing, poor access & dewatering

33. 33 AFTER CORRECTION Singapore Parallel Train Shoring improved Better access Dewatering improved

34. 34 THANK YOU “FOLLOW THE SAFETY R U LE AND BE SAFE” “NOBODY GETS HURT”