Basic First Responder Training for Incidents Involving Grain Storage Handling Facilities
Paper 1 - Case Studies of Incidents involving Formwork by Ms Azzalina.pdf
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Transcript of Paper 1 - Case Studies of Incidents involving Formwork by Ms Azzalina.pdf
8/12/2014
1
A Great Workforce A Great Workplace
SCAL Seminar 2014Case Studies of Incidents on Formwork
04 Dec 2014
Azzalina Zainuddin
Specialist
Construction Technology & Engineering
OSH Inspectorate
Understanding the Duties and Roles in Erection/ Use/
Dismantling of Formwork (Simplified*)
Formwork
PE
Formwork Supervisor
Employer
Occupier
- Check installation of
components of formwork
- Inspect formwork structure
upon completion
- Notify occupier if unsafe
Register
- Enter inspection into
register
-Provide design
calculations, drawings and
construction procedures for
the formwork
- Issue a COS if the
formwork is safe for use
- Appoint formwork sup
- Ensure that formwork sup
is trained
-Ensure that formwork
construction is supervised
by formwork sup
- Ensure that formwork:
a) Is properly constructed i.e.
is free from patent defect, is
safe for intended use etc.
b) Has safety factor of 2
c) Is designed by a PE if
criteria exceeded
d) If altered, is re-checked by
PE
e) Has safe means of access
for inspection
f) Has adequate bracings /
shores
g) Is dismantled only when the
concrete has gained
sufficient strength
h) Has adequate reshores if
required
(a) > 9 metres(b) > 2 tiers(c) > 300mm slab / beam
Suppliers
- Provide information on safe use
- Ensure equipment supplied is
safe when properly used
*Simplified for purpose of illustration
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Recent Spate of Formwork Related Accidents
Accident cases related to Formwork - 2013
An external wall formwork
toppled onto the Deceased
during the dismantling of the
wall form. He was trapped
between the toppled formwork
and the cantilevered work
platform behind him.
The Deceased was standing on
top of an L-shaped half of a
column formwork that was being
erected at the edge of the
building, when the column
formwork toppled over the
edge. He fell together with the
formwork to the ground level.
The Deceased was rectifying a
leak to a column formwork at the
edge of the building when he fell
over the building edge and landed
at the ground level.
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Accident cases related to Formwork -2013
Workers were tasked to pull up a
formwork panel using an
improvised pulley system. The
Deceased joined the group of
workers to pull a formwork panel.
The Deceased lost his balance and
fell off the edge of the work area.
The Deceased was carrying out
formwork erection for a beam
soffit, whilst doing so, he fell from
the edge of the formwork and
landed at the 2nd storey block
under construction
Accident cases related to Formwork - 2013
Casting works were being carried
out when portion of the formwork
collapsed. Collapsed caused the
falsework beneath the formwork
around the area to buckle.
Workers were carrying out
casting works for a slab when
an area which had been cast
earlier gradually gave way due
to buckling of the supporting
falsework.
A crane was deployed to load
formwork materials onto the
formwork deck, and when the load
was unrigged, the said section of
the formwork structure tilted
sideway and collapsed, causing all
the 5 workers working on the
formwork to fall from height.
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Accident cases related to Formwork - 2014
The Deceased and his co-workers
were tasked to lift a tableform from
one storey to a higher floor of a
building under construction. The
Deceased and a co-worker were
standing on top of the tableform
when it suddenly tipped over the
building edge. The Deceased
fell off the tableform.
The Deceased and co-workers were
tasked to perform concreting work of
the columns and beams of a skylight
roof. The formwork collapsed
inwards into the void area of the
skylight opening. The Deceased fell
together with the formwork.
A group of workers started to pour
concrete for a post-tensioned
beam when the formwork structure
collapsed. During the transit to
hospital, 1 of the workers
succumbed to his injuries.
Accident cases related to Formwork - 2014
The incident happened when the
concreters were casting the topping
on the precast formwork. The
falsework structure gave way during
concreting. A group of formwork workers
started to concrete the floor slab
of a light industrial building. A
portion of the slab being casted
started to sink slowly and
eventually collapsed.
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13
Formwork lapses
• Poor construction of formwork• Formwork with patent defects• No PE design for the mixture of
conventional formwork and system formwork
• No means of access and egress for the different levels of formwork
Working at Height Lapses
• Open sides• Ineffective barricades• Unsecured cover or no covers for floor
openings
Scaffold lapses
• Scaffold without adequate guardrail and toe-board
• No stairs or ladders for access/egress for scaffold
Common Contraventions leading to Issuance of SWO
Contraventions during inspections -
Working at Height without fall protection
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Contraventions during inspections -
No safe means of access / egress
Contraventions during inspections -
Inadequate Bracings
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Contraventions during inspections -
Patent Defects
Contraventions during inspections -
Deviations from PE Design
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Contraventions during inspections -
Mixed and Matched Formwork
Provisions for Work At Height
Recommendations
WSH Guidelines- Anchorage, Lifelines and Temporary Edge Protection SystemsLink:https://www.wshc.sg/wps/portal/resources?action=detailedInfoStop&fInfoStopID=IS2013050600735
WSH Guidelines - Personal Protective Equipment for Work at Heights Link:https://www.wshc.sg/wps/portal/resources?action=detailedInfoStop&fInfoStopID=IS2012120600720
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Supplier training for erection, transportation, use and dismantling of formwork – both practical and hands on
Recommendations
With particular attention to be placed on:
a) Installation or dismantling of components at the edge of buildings and structures
b) Processes and procedures for rigging and transportation of formwork
c) Proper erection of connections, supports etc.
Gaps and Issues relating to Formwork Construction
ADVISORY FOR
PROFESSIONAL
ENGINEERS ON
FORMWORK SAFETY
PRESS RELEASE ON
STEPPED UP
INSPECTIONS
Ensuring that formwork design is in accordance to regulatory requirements meeting:a) FS of 2.0;b) Provisions of horizontal and diagonal bracing in both longitudinal and transverse directions unless the formwork structure has been designed to be stable and rigid without bracing;c) Is designed by a PE for formwork covered under the requirements stated in WSH (Construction) Regulations 63(1)