This chapter explains about the process of installation steel framing component and to identify the safety aspect and the requirement during the installation process of steel framing component at site and to identify the level of safety during installation process at site.
For this chapter, definition and description of Industrialised Building System will be given. Beside that this chapter also included history of IBS in Malaysia, installation process, safety requirement during the installation work and more.
2.1.1 Industrialised Building System (IBS)
Industrialised Building System is a technology of construction which there are manufactured in controlled environment, either at off site or site. And then only transported, positioned and assembled into the construction works (CIDB, 2012). There are five main IBS groups identified in Malaysia, there are:
Abdullah and Egbu, 2009
IBS is the method of construction developed due to human investment in innovation and on rethinking the best way of construction work deliveries based on the level of industrialisation.
Hassim et. al, 2009
IBS is defined as an organisational process continuity of production, implying a steady flow of standardisation, demand, integration of the different stages of the whole production process, a high degree of organisation of work, and mechanisation to replace human labour wherever possible.
Chung, 2007
IBS is defined as a mass production of building components, either at site or in the factory, according to the specification with a standard shape and dimensions and then transporting them to the construction site to be re-arranged to a certain standard to form a building.
Badir et.al, 2002
IBS is defined as a concept of mass production of quality building by using new building systems and factory produced building component.
Haron et.al, 2005
IBS also defined as a new construction method that can increase the quality and productivity of work through the use of better equipment, materials, plant and machinery and extensive project planning.
Zulkefle, 2007
Defined IBS as a set of interrelated elements that act together to enable the designated performance of a building.
Hence, from the information I get they say that Industrialised Building System (IBS) is a process of the steel frame component are manufactured in the factory with standard requirement and then transported to the job site for installation to be assemble together to form a building.
Other than that, it is interesting to note that the term Industrialised Building System" (IBS) is often misunderstand as systems limited only for construction of building. But IBS actually covers all types of structures as the word building actually related to construction (Shaari and Elias 2003).
2.1.2 History of IBS in Malaysia
IBS were introduced in Malaysia in 1960's after the Ministry of Housing and Local Government of Malaysia visited several European countries and evaluate their housing development program"(Thanoon et.al,2003).
After their visit in year 1964, the first project using IBS had started by the government. To built quality and affordable house and speed up the delivery time were the aim for this project. About 22.7 acres of land along the Jalan Pekeliling, Kuala Lumpur was devoted to the project comprising 7 blocks of 17 stories flat, 3000 units of low-cost flat and 40 shops lot. This project was awarded to JV Gammon & Larsen and Neilsen using large panel precast concrete wall and plank slabs. The project was completed within 27 month including the time taken in the construction of RM2.5 million casting yard at Jalan Damansara (CIDB, 2006; CIDB, 2003 and Thanoon et al, 2003).
The second housing project initiated by the government comprise of 3 block of 18 stories flats and 6 blocks of 17 stories flats at Jalan Fifle Range, Penang in year 1965. Hochtief and Chee Seng was awarded by using French Estoit System (CIDB,2006; CIDB, 203 and Din, 1984).
Another earliest IBS project was at Taman Tun Sardon, Penang (1,000 units of five storey walk up falt). IBS precast component and system in the project was designed by British Research Establishment for low cost housing using precast system. A similar system was constructed at Edmonton, North London. About 20,000 precast dwellings were constructed throughout UK from 1964 to 1974 (CIDB, 2006). However, the building design was very basic and not considering the aspect of serviceability (Rahman and Omar, 2006).
Many construction in the following years utilised precast wall panel system. One can observed that IBS was engage at first place in the construction of low cost high rise residential building to overcome the increasing demand for housing needs (CIDB, 2006). However, the industrialisation of construction at the earlier stage was never sustained. Failure of early closed fabricated system made the industry players afraid of changing construction method. Some of the foreign systems that were introduced during late 60s and 70s were also found not to be suitable with Malaysia social practices and climate (CIDB, 2005).
Newer and better technologies were constantly being introduced in the market. Wet joint systems were identified to be more suitable to be used in our tropical climate. It also was better to utilised the bathroom types which relatively wetter than those in Europe (CIDB, 2005). In 1978. the Penang State Government launched another 1200 units of housing using prefabrication technology. Two year later, the Ministry of Defence Adopted large prefabricated panel construction system for constructing 2800 units of living quarter at Lumut Naval Base 9 Trikha and Ali, 2004). During the period of early 80s up to 90s the use of structural steel components turn particularly in high rise building in Kuala Lumpur. The usage of steel structure gained much attention with the construction of 36 storey Dayabumi complex that was completed in 1984 by Takenaka Corporation of Japan (CIDB, 2003 and CIDB, 2006).
In the 90s, demand for the new township has seen the increase in the use of precast concrete system in high rise residential buildings. Between 1981 to 1993, Perbadanan Kemajuan Negeri Selangor (PKNS) as state government development agency acquired precast concrete technology from Praton Haus International. It was based on Germany to build low cost house and high cost bungalow for the new townships in Selangor (CIDB, 2003 and Hassim et al.2009). It was recorded around 52,000 housing units was constructed using Praton Haus system (Trikha and Ali, 2004).
In the booming period of Malaysian construction 1994 to 1997, hybrid IBS application used in many national iconic landmarks such as Kuala Lumpur Convention Center, Bukit Jalil Sport Complex constructed using steel beam and roof trusses and precast concrete. Other than that, Lightweight Railway Train (LRT) and KL Sentral was constructed by using steel roof structure and precast hallow core. While KL Towe was built by using steel beams and column for tower head. Kula Lumpur International Airport (KLIA) was contructed by steel roof structure and Petronas Twin Towers was 9 steel beams and steel decking for the floor system. (CIDB, 2006)
The local IBS manufacturers were mushrooming, althrough yet to operate in full capacity. The current IBS systems used in Malaysia housing projects are steel frame, precast frame, formwork frame and large panel system. These system is largely used for private residential project in Shah Alam, Wangsa maju, and Pandan (Sarja, 1998), Dua Residency in Kuala Lumpur, Taman Mount Austin and Tongkang Pecah in Johor (CIDB,2006).
The new generation of building that utilised IBS is better as compared to conventional method in term of speed, cost, quality and architectural appearance. Steel frame, precast panel and other IBS systems were used hybrid construction technique to construct government building (CIDB, 2006).
2.2 Classification of IBS
This section will be explain the classification of IBS published in Malaysia. IBS was classified as a part of modern of construction (MMC).
MMC is term adopted as a collective description for both offsite based construction technologies and innovative onsite technologies. The latter includes techniques such as tunnel form construction and thin joint block work (Goodier &Gibb, 2006). MMC also include modern methods of construction of floor or roof cassettes, precast concrete foundation assemblies, preformed wiring looms, and mechanical engineering composites. They also can include innovative techniques such as thin joint block work or tunnel form (NAO, 2005 and Gibb and Pendlebury, 2006). As the reference, IBS is in which component are manufactured, positioned and assembled into a structure with minimal additional site works both on site or off site (CIDB, 2003 and Chung, 2006). While on on site IBS can be in the form of in-situ precast system using steel formwork and off site techniques is the description of the spectrum of which are manufactured assembled remote from building site prior to installation in their position. Whereas all off site may be regarded as falling within a generic IBS and MMC heading, not all IBS and MMC may regarded as off site (Gibb and Pendleton, 2006).
Pre-fabrication is a manufacturing process generally taking place at a specialised facility, in which various material are joined to form a components part of final installation (Tatum et al, 1986). While the components maybe assemble on and off site.
Pre-assembly carried on a definition as a process by which various material, pre-fabricated components and or equipment are joined together at a remote location for subsequent installation as a sub unit. it generally focused on system. Therefore, a generic classification of IBS-MMC term is promoted based on the following assumption compiled by the previous researcher.
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2.3 Activity in Steel Framing Construction
Erecting structural steelwork for building construction takes place in a dynamic, changing environment where there are many hazards and risks. Proper and timely planning and coordination are the most effective ways to manage those hazards and risks.
Projects involving structural steel construction have four main stages where risks to health and safety need to be considered:
• design
• fabrication
• transport
• erection.
Diagram 1
The functional relationship between each party is outlined in Diagram 1, on the previous page. Each party is responsible for the matters that are under its management and control. Managing risks arising from these matters is more effective when parties regularly consult one another and review how the next part of the process will proceed. For example, close co-operation between all parties is essential to ensure that the procedure for the erection of steel work is safe. They should:
• ensure the procedure is acceptable to all parties and signed off by the erection engineer
• review the procedure before activities begin.
2.3.1 Health and safety representatives
Planning and coordination must involve consultation with those engaged in the work and the health and safety representatives. A health and safety representative is elected by the workers to represent their health and safety issues at work. Health and safety representatives must be consulted alongside employees and contractors on issues relating to health and safety, including when processes are reviewed.
2.3.2 Key planning tools
There are six key documents which help ensure safe work in structural steel erection. There are:
construction drawings - architectural and structural
shop drawings - drawn up by the shop detailer, who is engaged by the fabricator, in consultation with the erection engineer, and detail what steel members are to be manufactured. Shop drawings are reviewed by the structural design engineer before fabrication
marking plans - developed by the fabricator and detail where steel members will be positioned in the erection process
sequential erection procedure - usually developed by the erector and approved by the erection engineer. The sequential erection procedure sets out the steps for the work in the correct order of erection
safe work method statement (SWMS) - developed by the erector in consultation with the crew and the builder, and identifies the hazards and risk controls for each step of the erection sequence
erection design - developed by the erection engineer based on the sequential erection procedures prepared by the erector.
2.4 Steel Frame Installation Procedure
2.4.1 Design stage
There are two separate phases of design in structural steel erection
i) Structural design
The first phase involves the structural design of the building, for in-service condition, which is carried out by the structural design engineer. The structural steel design should be produced according to the standard. Guidelines for the erection of building steelwork, which detail how risks can be eliminated or reduced in the design stage.
ii) Erection
The second phase, the design for erection, is for the handling, transportation and erection of the individual members and structure. It may be produced independently of the structural design of the building. Ideally, planning for the safe erection of structural steel work should be considered at the design stage. Structural design engineers should consider the safe working conditions for those involved in the erection stage, and eliminate as many of the hazards as possible at this stage.
Roles during design stage
The structural design engineer is responsible for the structural design of the building.
2.4.2 Fabrication stage
In consultation with the erection engineer, the shop detailer produces the shop drawings, and the fabricator works from these drawings to produce the steel members.
The structural design engineer should ensure that the shop drawings comply with the structural design. The drawings are reviewed by the structural design engineer before fabrication of the steel members.
Roles during the fabrication stage
The fabricator is responsible for the accurate detailing and fabrication of the steelwork to ensure members fit together correctly. Detailing should include the ease of making connections on site.
2.4.3 Transportation stage
Workers can be exposed to the risk of injury when loading, transporting and unloading steel from transport vehicles. Delivery of steel onto the site requires co-operation between the fabricator, builder, transporter and erector so that the steel is delivered in a timely and efficient manner, and that it does not overload the delivery area or the construction zone.
Roles during transportation stage
The transporter should have planned the routes and obtained all necessary permits and authorisation for oversize or wide loads, restricted routes, and more.
The transporter should be familiar with the builder's traffic management plan that includes, where necessary, traffic controllers, barricades and road closure permits to allow unimpeded access to the site.
The builder should also provide a safe and adequate unloading and lay-down area on the site and ensure that the transporter has detailed instructions on how to enter the site.
2.4.4 Erection stage
Safe erection of structural steel work depends on proper and timely planning. All personnel should be aware that erection of any structural steel is potentially hazardous and that planning must control any risk from these hazards.
Roles in the erection stage
Builder
The builder has overall management and control of the building site and should ensure that:
the building construction is in accordance with the project schedule
a traffic management plan is developed and implemented (which includes safe access /egress points and delivery areas)
a marking plan has been submitted
a delivery schedule submitted by the fabricator is agreed upon
the activities of all contractors are being coordinated and supervised
the ground surface or supporting structure is suitable for plant (such as EWP, mobile scaffolds and cranes) to operate safely
holding-down bolts, cast in concrete footing, pedestals or slabs, are within tolerance
shop drawings (prepared by the shop detailer) have a signed statement from the structural design engineer that the shop drawings comply with the structural design
the erection engineer provides clear advice on how to achieve stability for each stage of the structure's erection
weather conditions are continually monitored, particularly potentially hazardous situations like high or strong winds and electrical storms, and that a contingency plan has been developed for severe weather
at least one of the erection crew or another person who remains on site throughout erection should hold a current qualification as a Level 2 first aider
a safe work method statement has been developed and work is undertaken.
The builder must also provide to contractors a detailed site plan, which includes information on:
site location
access points
structure location
suitable ground bearing locations for crane operations
uploading areas
storage areas.
The builder should ensure that the accuracy of each contractor's work is within the tolerance of the level or position nominated by the erection engineer or relevant standard. Any modifications to the building layout also need to be checked by the builder for approval by the erection engineer.
Erection Engineer
The erection engineer approves the sequential erection procedure which includes how the structure is stabilised at each stage and signs any modifications, and is required to provide guidance to the builder and erection crew on matters including:
joints and additional erection cleats
structural design criteria affecting construction
temporary bracing
lifting points
loads and conditions likely to be experienced during the lifting and erection
any wind load limitations on the integrity of the structure as it is being erected according to the signed-off sequential erection procedure
wind load on the braced members.
joint positions (as they affect erection sequences)
accessibility of connections
fixings for working platforms, hand rails etc
preferred method of connecting steel members
preferred type and number of cranes to erect members of particular size and shape, and for vertical and horizontal bracing requirements
instructions on how to stabilise the structure at each stage of erection which involves:
verifying the adequacy of the base connections (steel to foundations)
checking stability under construction load conditions
capacity to withstand accidental vehicle impact.
Erector
the erector ensures that:
the structure is erected in accordance with the sequential erection procedure
work proceeds in accordance with the standard
confirms with the builder's representative that the ground or supporting surface is suitable for mobile plant to safely operate
pre-assembly of members and the movement and location of heavy members are considered prior to installation
weather conditions are continually monitored, and in particular, potentially hazardous situations like high or strong winds and electrical storms for which a contingency plan should be developed and implemented as required.
2.5 Safety in General
To ensure the possible protection for employees at the workplace, the co-operation efforts of both employers and employees will help in maintaining a safe and healthy work environment.
2.5.1 Personal Protective Equipment
PPE is defined in the Regulation as all equipment which is intended to be held by a person at work and which protects him against risks to his health and safety. For example, gloves, safety harnesses, eye protection, safety footwear, safety helmets and high-visibility clothing.
The hazard and types of PPE
Part
Hazards
Options
Eyes
dust ,radiation, chemical or metal splash, gas, and vapour.
Wearing safety spectacles, goggles, faceshields, visors.
Head
risk of head bumping, impact from falling or flying objects.
range of helmets and bump caps.
Breath
dust, vapour, gas, oxygen-deficient atmospheres.
Wearing disposable filtering face piece or respirator, breathing apparatus, and air-fed helmets.
Body
Adverse weather,
temperature extremes, chemical or metal splash, spray from pressure leaks or spray guns, contaminated dust, entanglement of own clothing, impact or penetration
Wearing boiler suits, specialist protective clothing for example:
high-visibility clothing
chain-mail aprons
Hands and arms
cuts and punctures, chemicals, temperature extremes, electric shock, impact, skin infection, abrasion.
Wearing gloves and gauntlets.
Feet and legs
Wet causes slipping, falling objects, puncture and cut, metal and chemical splash, abrasion.
Wearing safety boots and shoes with protective toe caps.
2.6 Safety in Steel Frame Installation
2.6.1 Managing risk at the design stage
Failure to plan and design for safety, from the outset, can result in unsafe practices onsite and in structural instability during erection. Accidents in the erection of structural steelwork are not restricted to falls. They can also occur because of structural instability during erection, and while handling, lifting and transporting material.
The stability of the building should be checked by the erection engineer at agreed times with the builder during erection. Special attention should be taken during design and construction in order to prevent progressive collapse. Progressive collapse define as a continuous array of failures causes by the local failure of one part of the structure.
Progressive collapse may be prevented by providing:
temporary bracing, shoring or ties
alternative load paths that cause applied forces to be safely transmitted through the structure
adequate structural strength and continuity of the structure and its parts.
The failure of a single member will not affected the whole collapse of the structure. This is especially important where structural stability was provided by wall bracing systems and steel roof. In addition, a well planning should be implement to the effects of unusual loads on the building, such as vehicle impacts and gas explosions.
The structural design engineer must provide sufficient details to allow the shop detailer to prepare shop drawings and the erection engineer to prepare the erection design
The shop drawings and erection design should be submitted to the structural design engineer for review to ensure that they comply with the requirements of the structural design
Before the shop drawings are produced, the parties involved in the design, fabrication, transport and erection process should liaise to plan the complete construction and erection sequence.
The table show what hazards may arise if the design does not adequately provide for safety in the erection of the structure. Methods for managing and controlling the risk of hazards are also provided.
Common hazards
the "build ability" of the design
Collapse of structure due to member failure from temporary loading during erection
Members not designed for transportation
Risk Control
The structural design engineer is required to provide design drawings which include:
purlin and frame detail
levelling pad detail
date and issue number of drawing
plans and elevations clearly indicating the structural framing and layout
the grade of steel member
reinforcement required for in-service loads and temporary conditions
structural design criteria affecting construction
make provision for positive connection between members of the structure that have been specified to resist imposed lateral and vertical force
Consideration should be given to details such as:
site limitations
delivery sequence
local street access
transport requirement
overhead obstructions.
2.6.2 Managing risk at the fabrication stage
Common hazards
Fabrication error
Incomplete fabrication (missing component)
Collapse of structure due to element failure
Members not clearly marked or identifiable
Weld failure due to poor quality or lack of testing
Incomplete or inaccurate shop drawing
Risk controls
The fabricator must:
ensure strength of members by using grades of steel which are in accordance with the relevant standards
ensure shop drawings comply with the structural design drawings
2.6.3 Managing risk at the transportation stage
Common hazards
Vehicle collision
Lack of set-up space
Access or egress: steep grade and short pitch
Worker falling from vehicle during loading and unloading
Steel falling from slung loads while unloading
Steel falling because the vehicle load is unstable or becomes unstable during unloading
Risk controls
Before loading vehicle
The fabricator should check that:
The sequence of loading is agreed between the fabricator and the builder
each member is clearly marked
The transporter should check that:
trucks have restraining spikes in place
steel is supported and secured, so that there is no uncontrolled movement of steel until it is ready to lift.
sufficient hardwood bearers, or equivalent, have been provided for loading.
The Builder should check that:
the sequence of loading is agreed between the builder and the erector
a crane of the required type and capacity is at the site
the area for unloading is firm and level and checked for load capacity and
where applicable or necessary, ground computations
there is an adequate set-up area
there is a traffic management plan
the grade and pitch of access/egress is suitable and safe for the vehicles
and their loads.
When loading the vehicle
The Transporter should check that:
the vehicle and load is stable and load will remain stable during unloading.
On vehicle's arrival at site
The Transporter should check that:
securing chains or straps are not removed until restraining spikes in place
the steel has not shifted into a dangerous position
the vehicle is positioned as directed by the erector and stabilised before the steel restraints are released
if the unloading sequence can lead to the instability of loads, the steel is individually restrained and the loading configuration checked so that unloading does not result in the load or the vehicle becoming unstable the vehicle is not moved without the steel being properly secured.
The Erector should check that:
loads are lifted in a level manner
loads are not lifted vertically or at a slope
loads are sufficiently secured to prevent inside lengths from falling out if the bundle is at an angle
there is fall protection for workers and doggers on the truck.
2.6.4 Managing risk at the erection stage
Common hazards
Falling from a height while rigging
Falling objects
Collapse of the structure during construction
Being struck by plant
Plant contacting underground or overhead utility services
Being struck by objects such as steel members
Risk Controls
The erector should reduce the need for work at height by:
constructing as much of the steelwork as possible (such as modules or frames) at ground level, or from erected floor slabs or decks in the structure, and
where reasonably practicable, releasing the lifting sling or device from ground level by the use of long slings, remote release shackles or other suitable devices.
The erector should prevent the risk of a fall of a person working at a height by using in order of effectiveness:
passive fall prevention devices, for example, work platforms
work-positioning systems such as travel-restraint systems and industrial rope-access systems, and
fall arrest systems such as catch platforms and safety-harness systems.
The erector should reduce the risk from falling objects by:
restricting access when there is overhead work by establishing, where practicable, exclusion zones
preventing, where practicable, loads being lifted or transported over people or amenities
ensuring only rigger slings loads and, where appropriate, fix tag lines
using lifting beams to position members where necessary to ensure the stability of the member
considering perimeter screens, guardrails with integral toe-boards and wire mesh, debris nets, cantilever work platforms, scaffolding sheathed with protective material and/or lanyards to secure tools and equipment
using materials boxes which are fully sheeted to enclose the load
ensuring safety helmets are worn at all times.
a) Before erection, to avoid collapse, the erector should:
ensure a sequential erection procedure is prepared, which has been approved by the erection engineer and is consistent with the marking plans
ensure that an experienced steel erection supervisor is present at all times to oversee the implementation of the sequential erection procedure
ensure an adequate exclusion zone to prevent risk to other people not involved in the erection
only start the erection of a member or sub-assembly when equipment to ensure the structure's stability is available and being used
ensure temporary guys or bracing are securely anchored
place adequate visual barriers between guys and plant/vehicle movement areas.
b) During erection, to avoid collapse, the erection supervisor must:
verify the stability of the structure in accordance with the erection engineer's specifications:
at the end of each work day
when fastenings may be incomplete
during strong winds or when strong winds are forecast
seek approval from the builder (or erection engineer where appropriate) to cease work at unscheduled points where the structure has not been completed to the specifications of the erection engineer's design
Obtain, from the builder, the erection engineer's written approval before loads are placed onto the structure
where possible, start erection in a nominated braced bay. If this is not possible, make sure that the erection engineer is involved in developing an alternative site-specific sequential erection procedure.
check the fittings for the support of columns during erection, to ensure adequate structural capacity for the erection conditions
make sure that all beams are secured before releasing the slings
make sure that all bolted connections are effective to ensure the stability of the steel structure.
4 To avoid being struck by plant and before the use of a crane or any other powered mobile equipment, the erector should consider:
crane selection,
protection of the public
the location of any excavations or underground services that may affect a crane load
the proximity of overhead power lines
the capacity of the ground or supporting surface to bear the load
check the type and amount of packing required under the crane's outriggers to support the proposed loads
written procedures for setting up and dismantling of the crane and the lifting method
the composition of the rigging crew suits the job
procedures for visual and audible signals between the crane operator and the erection crew
ground support conditions
selection of lifting gear
emergency procedures
prevailing or forecast weather conditions
the need to avoid lifting loads over people.
The use, of two or more cranes to move and position loads, is hazardous and should be avoided if a single crane is capable of doing the job. Where it is necessary to use two cranes to dual lift members, the following controls are to be implemented:
the weight of the load and its centre of gravity as well as the weight of the lifting gear must be carefully calculated.
cranes of similar characteristics should be selected.
the position of each crane should minimise movement and slewing.
the lifting capacity of each crane must be 20% greater than the share of the load.
5. Where plant is working near overhead lines, the erector should:
identify all power lines services before permitting any crane or other mobile plant on site
check that material and plant is moved or operated outside the "No Go Zone" of 3000 mm from an overhead electrical cable on a pole or 8000 mm if the electricity cable is on a tower line (If erecting scaffolding, the "No Go Zone" during this process is 4.6m distant and 5m below from the nearest power line)
if work or plant is able to encroach on this clearance, the erector must obtain permission from the electricity company.
2.6.5 Other hazards
hazards must be controlled. They may include:
noise
manual handling
hot work
exposure to hazardous substances
dangerous goods
electrical work
sun (UV) exposure.
