Trevor Pavitt

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Trevor Pavitt
All information contained in this presentation is
confidential and the property of Alistair Gibb of
Loughborough University. No part of this
presentation may be duplicated without the
authors specific consent. The information
presented has been shown in good faith.
www.apache4change.com
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Designers dangerously unaware of CDM duties SHP
June 2003
Occupational health is a major problem for
construction Between 2001 and 2002 79 people died
in construction and there were 3959 serious
accidents. Over the same period the HSE estimates
that 137 000 construction workers suffered from
ill-health caused, or made worse by their job
(HSE, Building, 11 July 2003). We need to put
the health back into health and
safety Work-related ill-health is
under-recognised, under-reported, under-diagnosed
and under-managed (Dr Andrew Colvin, medical
advisor to CTRL) Designers can make a
difference Hazards are introduced at the earliest
stages in a projects life and can often be
eliminated and risks reduced through the design
process (CONIAC HSC/M1/02/3). But designers
often dont know what to do HSE found that a
third of designers on major construction projects
demonstrated little or no understanding of their
responsibilities to design-out risks (SHP June
2003). D4h provides designers with an
opportunity to make a difference to the
occupational health of construction workers
Vital to eliminate health hazards in
design Lawrence Waterman, Sypol Building, July
2003
Designers unaware of their duties under
CDM Croner July 2003
HSE targets consultants for ignoring safe
design NCE March 2003
Designers face clamp down after safety blitz NCE
May 2002
Clients and architect ignore safety Building 16
August 2002
Ill-health is like a slow-burning accident Kevin
Myers, HSE Building July 2003
One in three designers ignores safety Building
May 2003
CDM Confusion, Despair and Mayhem NCE July 2002
Designers have no idea Construction News May
2003
Continue
Alistair Gibb, Trevor Pavitt, Katie Horne, Roger
Haslam APaCHe, Loughborough University ISBN XXX
YYY 111 000
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D4h Designing for health Best practice exemplars
Alistair Gibb Roger Haslam Katie Horne Trevor
Pavitt
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Recent APaCHe Projects

• ConCA Accident Causality
• Better, easier, safer design
• ECI SHE manual
• ECI Health manual.

www.apache4change.com
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Current APaCHe Projects

• D4h - Designing for Healthy Construction
• HAVS - Hand-Arm Vibration study (CTRL)
• Kerbs - Manual handling (CHSG)
• CIRIA - Health Manual for Workers
• HASPREST HS and Off-Site Production.

www.apache4change.com
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APaCHe Projects D4h Designing for healthy
construction

• 18 month project started July 2002
• DTI Pii funding Value 250k
• Identify best practice
• Adapt to mainstream sector
• Produce guidance for designers
• Loughborough team
• Katie Horne, Trevor Pavitt and Charlotte Brace.

www.design4health.com
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D4h Designing for Health

• Establishing best practice for designers reducing
  occupational health risks during construction
• Developing strategy and guidance.

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Why occupational health (OH) and the need to
design-out hazards are both important.
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Health and Design

• OH is the poor relative of SAFETY
• TMCS Directive (CDM) requires designers to act
• OH can not be ignored
• 79 fatalities in 2001-2002
• 3959 serious accidents
• 137 000 OH cases.

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Health and Design

• Very little good practice by designers
• Only 33 had sufficient knowledge of their duties
  (HSE Survey)
• Only 8 had had any training (HSE Survey)
• It has been hard to find exemplars
• But. the supply-chain is innovating.

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D4h Tool

• Provides strategic guidance for the concept
  design phase
• Provides element-specific guidance for the
  detailed design phase
• Identifies main activities and health hazards
• Suggests designer action to remove/reduce risk
• Provides exemplars to illustrate the benefits.

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Piling exemplar

• Many health (and safety) hazards
• Key health hazard from removal of pile top
• Hand-held pneumatic breakers.

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• Main piling activities
• Main piling health risks
• Pile top break down health risks
• Innovations to reduce pile top break down health
  risks
• Elliott pile break method
• Recepieux pile break method
• Taets hydraulic pile break method
• Cementation-Skanska sacrificial guide wall

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Main piling activities
D4h Major Building Pile top break down

• 1 Auger fitted with appropriate head
• 2 Auger drilled into ground to required depth
• 3 Concrete poured down hollow core of auger
  whilst auger is removed
• 4 Steel reinforcement cage pushed into wet
  concrete
• 5 Wet concrete overspill at ground level removed
• 6 Ground level reduced and top section of pile
  broken down to desired level
• 7 Pile cap or capping beam constructed.

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Main piling health risks
D4h Major Building Pile top break down

• 1 Manual handling aspects to changing auger heads
• 2 Contaminated land hazards
• 3 Dermatitis and other cement-related hazards
• 4 Manual handling and injury risks in placing
  rebar cage along with cement-related hazards
• 5 Cement related and manual handling hazards
  (excess concrete typically removed by hand)
• 6 Major hand-arm and whole body vibration hazards
  (HAVS/WBVS), noise, dust and other manual
  handling hazards
• 7 Insitu concrete hazards (many and various).

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D4h Major Building Pile top break down
Main piling health risks
Survey results from Designers/Planning
Supervisors (APS Aberdeen and Newcastle
9/03)Red/Yellow - High risk Black/Blue - Medium
risk Blue/White Low risk
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D4h Major Building Pile top break down
Pile top break down health risks
Skin cancer from excess sun exposure
Site Helmets
Ear protection to reduce risk from noise
Eye protection to reduce risk from debris

• This image shows a real-life construction site
  situation
• In this case mostly poor practice
• The boxes identify some of the main health
  hazards
• Green boxes show where the site team have taken
  some action to reduce or control the risk
• Red boxes show where they do not appear to have
  taken such action
• In either case D4h aims to take action during
  design to avoid or reduce the risks before they
  reach site
• This image was not taken from a project involving
  a D4h collaborator

HAVS / WBVS from breaker vibration
MSDs from bad posture and restricted work area
Silicosis from cement dust
Dermatitis from cement exposure
Additional safety-related issues include Injury
from exposed reinforcement Unsecured
ladder Struck by machine Falls / trips on
debris PPE eg boots, overalls, hi-visibility
vests Undermining timber hoarding
? Loughborough University Image courtesy
Loughborough University
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D4h Major Building Pile top break down
Occupational Health Innovation Pile break method
(Elliott) Main health issues addressed HAVS and
other health risks associated with breaking down
of the tops of insitu bored piles Description Thi
s technique involves the removal of the unwanted
pile section in one piece, exploiting the physics
of crack propagation. Steel reinforcement above
the final cut-off level is prevented from bonding
with the concrete by fixing isolating sleeves to
the bars before the cages are lowered into
position (1). When the pile is finally exposed a
51mm diameter hole is drilled horizontally into
the concrete at cut-off level to just beyond the
centre of the pile (2). A standard hydraulic
splitter is inserted and activated (3) and after
around 30 seconds the concrete cracks across the
desired level. Then an excavator is used to lift
off the surplus in a single piece via a lifting
eye cast into the top surface (4). Elliot claim
that the operation cuts the hand-arm vibration
risk by more than 90. It will work on pile
diameters from 300mm to 3m and typically takes
around 10 minutes (5), bringing significant
productivity and cost benefits. Design action
required Actual choice of technique is probably
left to the Principal Contractor. However,
designers should identify the significant risk
and ask the PC for proposals to remove the risk
(knowing that there is an answer). Main residual
health risks One 51mm hole is drilled into the
pile with some associated vibration hazards
(approx 5 minutes task time). Some MSD hazards
may remain in the manoeuvring of the pile top
section although this is a crane
operation. Note There are a number of
alternative methods addressing this health risk.
(link to table)
?Loughborough University Images courtesy Elliott
www.Elliott-Europe.com
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Elliott Crack Propagation
Courtesy Elliott
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D4h Major Building Pile top break down
Occupational Health Innovation Chemical pile
break method (Recepieux) Main health issues
addressed HAVS and other health risks associated
with breaking down of the tops of insitu bored
piles Description Recepieuxs technique involves
the removal of the unwanted pile section in one
piece, exploiting the principle of crack
propagation induced using an expanding grout.
The steps are as follows 1 Foam sleeves are
fixed over the reinforcement over the length to
be removed 2 A series of PVC tubes and cones is
assembled 3 The tube and cone assembly is pushed
into the wet concrete 4 The tube assembly is
checked for level and funnels fixed to the top of
the tubes 5 The temperature of the pile concrete
is measured (this affects the grout mix choice) 6
The expanding grout is mixed and batched into
containers 7 The grout is poured into the tubes
via the funnels 8 The grout expands in the cones
set at cut-off level propagating a horizontal
crack through the pile 9 The top unwanted
section is removed by crane Design action
required Actual choice of technique is usually
left to the Principal Contractor. However,
designers should identify the significant risk
and ask the PC for proposals to remove the risk
(knowing that there is an answer). Main residual
health risks COSHH issues with the grout and
increased work required to the wet concrete
during pile construction. Some MSD hazards may
remain in the maneuvering of the pile top
section. Note There are a number of
alternative methods addressing this health risk.
(link to table)
Note there are examples of poor use of PPE in
these images
?Loughborough University Images courtesy
Recepieux (http//www.recepieux.com)
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Recepieux Chemical Crack propagation

• Traditional insitu bored pile cast approximately
  1m above cut-off level
• Horizontal crack induced at cut-off level by
  expanding grout inserted through tubes.

Courtesy Recepieux
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Recepieux Chemical Crack propagation
Courtesy Recepieux
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D4h Major Building Pile top break down
Occupational Health Innovation Hydraulic pile
break method (Taets) Main health issues
addressed HAVS and other health risks associated
with breaking down of the tops of insitu bored
piles Description The Taets system from the
Netherlands replaces hand-held pneumatic breaking
with a large scale hydraulic breaker. The
breaker is suspended from an excavator and makes
a horizontal fracture in the pile at cut-off
level. Each hydraulic cylinder drives a chisel
into the concrete producing a horizontal
fracture as the breaking force built up this way
always seeks the shortest way through the
concrete. This stage takes about 25 seconds. The
steel chisels do not have to penetrate beyond the
reinforcement bars. After the fracture is made,
the chisels penetrate further into the concrete
(usually 25-40 mm). Due to the shape of the
chisel, in combination with the reaction forces
on the concrete by the steel reinforcement, the
concrete breaks into pieces and can removed
without the need for further breaking. Design
action required Actual choice of technique is
probably left to the Principal Contractor.
However, designers should identify the
significant risk and ask the PC for proposals to
remove the risk (knowing that there is an
answer). Main residual health risks Slight MSD
risk maneuvering breaker although this is a crane
/ excavator operation. MSD risks disposing of
broken concrete depending on techniques used.
Some dust and noise. Note There are a number of
alternative methods addressing this health risk.
(link to table)
? Loughborough University Images courtesy Taets
(http//www.taets.nl/B)
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D4h Major Building Pile top break down
? Loughborough University Images courtesy Taets
(http//www.taets.nl/B)
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D4h Major Building Pile top break down
Occupational Health Innovation Hydraulic pile
break method (Mantovanibenne ) Main health
issues addressed HAVS and other health risks
associated with breaking down of the tops of
insitu bored piles Description The
Mantovanibenne system replaces hand-held
pneumatic breaking with a large scale hydraulic
breaker in a similar way to the Taets system.
This system was recently used on Norwich FCs
Carrow Road ground (NTW Civil Engineering /
Inmalo). The system can accommodate piles
between 350 and 1600mm for both circular and
square piles. The team claim significant
productivity as well as health and safety
benefits (Construction News, 11/09/03
p.20). Design action required Actual choice of
technique is probably left to the Principal
Contractor. However, designers should identify
the significant risk and ask the PC for proposals
to remove the risk (knowing that there is an
answer). Main residual health risks Slight MSD
risk maneuvering breaker although this is a crane
/ excavator operation. MSD risks disposing of
broken concrete depending on techniques used.
Some dust and noise. Note There are a number of
alternative methods addressing this health risk.
(link to table)
? Loughborough University Image courtesy
Mantovanibenne
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D4h Major Building Pile top break down
? Loughborough University Courtesy Mantovanibenne
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Option 4 Hydraulic breaker

• Traditional insitu bored pile cast approximately
  1m above cut-off level
• Hand-held breaking replaced by crane-handled
  hydraulic breaker.

Courtesy Taets
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D4h Major Building Pile top break down
Occupational Health Innovation Precast
sacrificial guide wall (Cementation-Skanska) Mai
n health issues addressed HAVS and other health
risks associated with breaking down of the tops
of insitu bored piles, along with other pile top
hazards Description Contiguous piled walls
require more accurate alignment and need a
temporary, sacrificial concrete guide wall to be
cast before the piling operations through which
the auger passes. The Cementation-Skanska system
prevents the abortive work of the early guide
wall, which in the final permanent state is
usually replaced by a concrete capping beam of
similar dimensional proportions. The system
utilizes pre-cast concrete guides placed into
position and retained by a non-structural
concrete surround. By preventing contamination
to the tops of the piles, they can be poured to
cut-off level in the first place removing the
need to break-down the pile tops. Circular voids
in the mould allow the piling auger to pass
through the mould in the required position.
Adjacent voids are protected with circular lids
to prevent them being filled with concrete or
pile arisings. 1 - guide blocks being placed
along the line of the wall 2 - auger drilling
through the block guides 3 - blocks removed
after the piling operation and also the shape
left by the blocks acting as the formwork for the
capping beam. Design action required Actual
choice of technique is probably left to the
Principal Contractor. However, designers should
identify the significant risk and ask the PC for
proposals to remove the risk (knowing that there
is an answer). Main residual health
risks Additional operations involve the placement
of the precast guide wall units which may involve
some MSD hazards. Note There are a number of
alternative methods addressing this health risk.
(link)
?Loughborough University Images courtesy
Cementation Foundations - Skanska
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Cementation-Skanska sacrificial guide wall

• Designed for contiguous piling
• Enables pile to be cast to cut-off level
• Avoids contamination of wet concrete from
  surrounding ground
• Avoids need for breaking down pile top.

Courtesy Cementation-Skanska and Carillion
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D4h Major Building Pile top break down
Innovations to reduce health risk Innovations to reduce health risk Innovations to reduce health risk
Method Health hazards reduced / removed Residual health hazards
Elliott crack method Manual removal of pile top is avoided by the crack splitter resulting in a large concrete section removed by crane 51mm hole drilled into the pile with some associated vibration hazards. Some MSD hazards may remain in the manoeuvring of the pile top section.
Recepieux chemical method Manual removal of pile top is avoided by the chemical technique resulting in a large concrete section removed by crane COSHH issues with the grout. Increased work required to the wet concrete during pile construction. Some MSD hazards may remain in the manoeuvring of the pile top section.
Taets hydraulic breaker Manual removal of pile top is replaced by a crane-handled hydraulic machine Some MSD hazards may remain in the manoeuvring of the hydraulic breaker and in the ultimate removal of the broken concrete.
Cementation sacrificial guide wall (contiguous piling) The need for over-pouring of the concrete pile is removed as the pile is poured to the correct cut-off level, protected from contamination of the surrounding ground by the precast guide wall. Additional operations involve the placement of the precast guide wall units which may involve some MSD hazards.
?Loughborough University
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Designer/PS knowledge of pile break innovations
Sample size 40 Main primary function designers
(Arch Eng) Main secondary function Planning
Supervisors
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D4h Designing for healthy construction

• The challenge..
• To design-out health risks for construction
  workers
• Are we aware of the innovations?
• Do our designs preclude their use?
• Do we have mechanisms in place to access expert
  knowledge?
• Are we proactive in encouraging design
  innovations?.

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There is a better way!