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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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Observations from Operations

SWOs related to Formwork (Apr 2014)

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SWOs related to Formwork (Apr 2014)

SWOs related to Formwork (Jan 2014)

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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)

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