Access / Egress Mobile equipment. …..Excavation hazards
Prior to Excavation Obtain a work permit Check Ground / Soil condition Check Ground / Surface Water Check the Location of Water Table Check Under ground / Overhead utilities Adjacent buildings Dynamic load / Traffic
Type A : Clay, sandy clay, clay loam Type B : Angular gravel (similar to crushed rock), silt, silt loam, sandy loam Type C: Gravel, sand, loamy sand,Submerged soil or soil from which water is freely seeping; or Submerged rock that is not stable Soil Classification
Preventing Soil Collapse Soil classification (Type a, b, or C) Sloping Benching Placing a shield. Shoring(Timber / Aluminum shoring Sheet piling
Your choice of protection Sloping Benching Shoring Shields Designed by a Registered Project Engineer
Simple Sloping Short term up to Stable Rock : 90 0 Type A - 3/4: Note :Greater than 20 feet deep shall be designed by a registered professional engineer.
Simple Sloping -Type A Soil Unsupported Vertically-Sided Lower Portion <12 ft Unsupported Vertically-Sided Lower Portion <8 ft
Supported or Shielded Vertically-Sided Lower Portion Simple Sloping -Type A Soil
Simple Sloping Type B - 1: Type C - 1½ : Note :Greater than 20 feet deep shall be designed by a registered professional engineer.
Benching Type A Type B (cohesive)
Basic components of shoring
Shoring in Footing foundation OUTWARD SLOPE ( 35* TO 40*) CONSIDERING ONGOING RAINY SEASON
Arrangements in Water Logged Area SUPPORT TO THE WALL OF EXCAVATED PIT
Timber Shoring Installations REFER TO DESIGN ENGR.
Utilities Underground PERMIT SYSTEM
EFFECTS OF UTILITIES ABOVE GROUND UNDER GROUND
EFFECTS OF UTILITIES EXPLOSION FIRE
UTILITIES PREVENTION Obtain work permit and get clearances from the concerned Electricity Water & Sewage Pipeline Communication Oil & Gas Pipe Line Use Detectors ( for More Reliable)
Water Accumulation Ground water Surface water
Hazardous Atmospheres Never Start Work if, Oxygen Level less than 19.5 % Permissible limit of the toxic gases exceeded. More than 20 % of Lower Explosive Limit. PRECAUTIONS Ventilation to over come the above said. Blocking the source, incase of toxic and flammable gases. (Using other effective controls to reduce the level of atmospheric contaminants to acceptable levels)
Adjacent Structures Ensure structure stability Shoring Bracing Evaluation by Professional
FALLING LOAD Gravity Weight of soil pile Weight of near by structures Weight of personnel &equipment Vibration PREVENTION Never operate a construction equipment within 2.5 m from the edge of the excavation. Stacking the material 1 Meter away from the edge of the excavation.
Access –Ladders every 9.14 m Length – Normal every 4.6 m length – Hazardous operation –Ramps with slope not more than 15 o –Stairs cut on earth
Vehicle Traffic Control Measures Traffic Management Plan Traffic Control Traffic Safety Vests Fencing Illumination
Traffic Control Device & Vest
Fencing Hard Barrication shall be provided, in the fall prone areas and if depth is more Physical barricades required always Must be placed 2m away from excavation edge. Standard fall protection required for vertical falls over 1.3m Traffic diversions Pedestrian walkway diversions
Reflective Cone Barricades Caution Signs
Temporary Lightings: Sufficient Area Lighting. Emergency Lighting with Power back up. ILLUMINATION
Excavation Inspections Daily Inspections by Competent Person Start of shift, as needed, following rainstorms or other hazard-increasing event Possible cave-ins Protective system failure Water accumulation Hazardous atmospheres
Safety awareness – Supervision Develope - personnel interested on Safety, Safe work procedures considering the ground realities. Awareness and motivating the supervisors concerned, Develop system to report, analyze and prevent Near- miss cases. Developing gang leaders and attitude,