safety in excavations presentation
DESCRIPTION
Safe procedures for excavationTRANSCRIPT
Safety in ExcavationsSafety in Excavations
A guided study of understanding
the risks and dangers in excavation work
Topics to be DiscussedTopics to be Discussed
Soil Types Shear Strength Collapse Types Strength Factors Protective Measures
Safety in ExcavationsSafety in Excavations
In General:In General: An employer is required to provide
safe means of access to and egress from a work area above or below ground level by means of stair, ladder, runway or ramp.
The access way must be well maintained well-lit, clear of obstructions, and be suitable abrasive to ensure firm footing for workers.
Safety in ExcavationsSafety in Excavations
Excavation work cannot commence until the Labour Division has been notified and the employer has received a registration number and has notified public utilities.
If the employer does not perform the excavation in accordance with the Construction Industry Safety Regulation of the Workplace Safety and Health Act, the registration may be revoked and the excavation shut down.
Safety in ExcavationsSafety in Excavations
Soil TypesSoil Types
Soil TypesSoil Types
Stable Rock Type A Soil Type B Soil Type C Soil Layered Geological Strata
Safety in ExcavationsSafety in Excavations
Shear StrengthShear Strength
Shear StrengthShear Strength
“ “ The capacity of a material The capacity of a material to resist the internal and to resist the internal and external forces which slide external forces which slide past each other “past each other “
Shear StrengthShear Strength
Cohesion The stickiness of the soil; a greater
amount of clay than sand.
Internal Friction A result of particle shape.
Safety in ExcavationsSafety in Excavations
Strength Strength FactorsFactors
Strength FactorsStrength Factors
Water Vibrations Erosion and Weathering Excavation Depth Slope Steepness Degree of Soil Compaction
Safety in ExcavationsSafety in Excavations
Collapse TypesCollapse Types
Collapse TypesCollapse Types
Zone of Exposure
Collapse TypesCollapse Types
Zone of Exposure Spoil Pile Slide
Collapse TypesCollapse Types
Zone of Exposure Spoil Pile Slide Side Wall Shear
Collapse TypesCollapse Types
Zone of Exposure Spoil Pile Slide Side Wall Shear Slough – in
Collapse TypesCollapse Types
Zone of Exposure Spoil Pile Slide Side Wall Shear Slough – in Rotation
Safety in ExcavationsSafety in Excavations
Shoring TechniquesShoring Techniques
Shoring TechniquesShoring Techniques
Engineers are often required to design shoring, which is a construction procedure used specifically to maintain the stability of the walls of an excavation and provide protection to workers who may enter the excavation
Shoring TechniquesShoring Techniques
Accidental Falling Entry
Excavation sites cannot be crowed with anything such as piles of excavated material or excavation equipment which might accidentally fall into the excavation.
All work areas adjacent to public walkways must be adequately guarded or barricaded by fences, guardrails or a covering sufficient to prevent persons from falling into the excavation.
Shoring TechniquesShoring Techniques
Shafts and Tunnels
Due to the specific nature and hazards of the work, a professional engineer may be required to design a support structure for a shaft or tunnel prior to commencement.
At least one worker in each work crew must be experienced in the type of work being performed in shaft and tunnel excavations, and at least one worker is required to be trained in first aid.
Shoring TechniquesShoring Techniques
Access Way
Employers must surround the opening to an underground excavation with a firm, level area and a protective barrier (at least 1 meter in height) surrounding it.
The access way must be secured with a cover to prevent unauthorised entry.
Access landings, the bottom of shafts and tunnels, and other similar work areas must be kept free of loose mud and other accumulations of debris.
Shoring TechniquesShoring Techniques
Atmosphere
Every employer must provide a suitable ventilation system in a shaft or tunnel excavation to ensure that there is no lack of oxygen and that concentrations of toxins in the atmosphere are minimised.
No employer shall allow internal combustion engines to be used in underground work areas unless the engines are properly engineered to do so.
Shoring TechniquesShoring Techniques
Illumination
Every employer must provide electrical illumination for the full length of the tunnel and at the face of the excavation where inadequate natural light is present.
Where electrical illumination is used in an underground excavation, employers are required to provide an emergency lighting system.
Shoring TechniquesShoring Techniques
First Aid in Shafts and Tunnels
Employers must ensure that: At least one worker holding a valid first aid
certificate must be present during each shift. A first aid kit is provided in the immediate
vicinity of the entrance to a shaft or tunnel. A basket stretcher and blankets are provided
at each worksite. Workers are instructed in proper underground
rescue procedures.
Shoring TechniquesShoring Techniques
Flammable and Combustible Hazards
Flammable and combustible liquids shall not be used underground unless they are stored in accordance with the Manitoba Fire Code.
Effective means for extinguishing a fire in an underground excavation must be provided where combustible or flammable materials may be present.
Shoring TechniquesShoring Techniques
Wood Support
Shoring TechniquesShoring Techniques
Wood Support Screw Jacks
Shoring TechniquesShoring Techniques
Wood Support Screw Jacks Hydraulic Shores
Shoring TechniquesShoring Techniques
Wood Support Screw Jacks Hydraulic Shores Spacing
Shoring TechniquesShoring Techniques
Wood Support Screw Jacks Hydraulic Shores Spacing Trench Cages
Concluding RemarksConcluding Remarks
Excavation Work is a highly dangerous Excavation Work is a highly dangerous industry. Safety standards need to be industry. Safety standards need to be implemented and stringently implemented and stringently maintainedmaintained