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PROCEDURE FOR SCAFFOLDING WORK
1) All scaffold work shall meet the requirements of this General Instruction of Client Company Scaffold Safety Handbook (SSH).
2) All scaffolds shall be built in accordance with the work process/decision flowchart, including formal scaffold plan review, inspection, tagging, etc. However, non-mobile, base-supported scaffolds less than 1.8 meters (6 feet) tall do not need to be in accordance with Supplement 8.001-1, unless located near the edge of an elevated structure with a protected or un protected fall potential of more than 1.8 meters (6 feet).
3) For scaffolds equal to or less than 12.2 meters (40 feet) tall, the Proponent shall decide whether to use a Client Company maintenance group or an outside contractor, giving due consideration to their in-house capabilities and the 1) This instruction covers all the work activities associated with scaffolding work and formwork system to be performed by Subcontractor.
a) Steel pipe scaffolding have main and exterior scaffolding, and steel pipe main scaffolding is composed of column, wale, common joist, strut, wall connection, mouthpiece joint, mouthpiece clamp and base hardware. Steel pipe scaffolding collapse accident is mainly caused by faulty wall connection, which would cause buckling and lead to collapse. It is due to column, wale and common joist connection is caused by clamp (close to hinge connection). Therefore, steel pipe and auxiliary hardware shall be approved by safety standards, free from crack and twists due to external force, and shall not decay.of the required scaffold(s).
WORK PROCEDURE
1) This instruction covers all the work activities associated with scaffolding work and formwork system to be performed by Subcontractor.
a) Steel pipe scaffolding have main and exterior scaffolding, and steel pipe main scaffolding is composed of column, wale, common joist, strut, wall connection, mouthpiece joint, mouthpiece clamp and base hardware. Steel pipe scaffolding collapse accident is mainly caused by faulty wall connection, which would cause buckling and lead to collapse. It is due to column, wale and common joist connection is caused by clamp (close to hinge connection). Therefore, steel pipe and auxiliary hardware shall be approved by safety standards, free from crack and twists due to external force, and shall not decay.
Please read also: PROCEDURE FOR CONCRETE WORK-CIVIL
b) Steel pipe fabrication and structure
Equipment Safety Harness : equipment safety harness if working above 2 m height Wall connection: Connect with the structure with connecting hardware per 5 m vertical interval and 5 m horizontal interval. Work footing : Work footing shall be of 40 cm or greater width, 3.5 cm or greater thickness and 3.6 m or less, install more than 2 supports per 1 footing, overlap more than 20 cm for joints, and the center shall be placed on the common joist. Wale installation : Fix onto scaffolding column and wale with 10 m interval and 45° angle. Railing installation : Top railing (H:90cm), middle railing (H:45cm)
Sign post : Maximum load capacity (<400kg), danger warning and direction sign installation Foundation reinforcement and sleeper : Commence foundation reinforcement to prevent slippage and settlement, and install planch and sleeper at the bottom.
Installation spacing : Beam direction(Scaffolding column) 1.5~1.Bm, room direction less than 1.5m, scaffolding sleeper less than 1.5 m, and install first wale within 2m height from the ground.
Bottom supporting hardware : Connect with bottom supporting hardware at support bottom to prevent slippage and settlement.
Miscellaneous
c) Work supervisor shall remove defective products after inspecting steel pipe fabrication conditionand connection prior to work.
d) Supports shall be reinforced at the bottom to prevent settlement and movement.
e) Support spacing shall be within 1.5~1.Bmin wale direction and within 1.5m sleeper direction.
f) Support exceeding 31 m from support top shall be in a double layer.
g) Support, wale, horizontal member and strut connection shall utilize suitable accessories (clamp, bolt, etc.), and shall not use steel wires or equivalent.
h) Support and wale connection shall not be in an identical line.
i) All supports and struts shall cross each other.
j) Spacing shall be within 1 m if wall connections are composed of tension and compression members.
2) Steel pipe use and management
a) Take cautions for the following regarding steel pipe use and management. Loading capacity per support shall be less than 400 kg, and limit load less than 700 kg for each support if work above scaffolding is performed below 2nd floor.
b) Do not load materials that are not used for work on scaffolding. If inevitable, materials shall be placed to prevent fall.All unnecessary material above the scaffolding shall be neatly sorted.
Equipments to prevent fall shall be installed if moving up and down around the high scaffolding area.
c) Inspect the followings on scaffoldings to repair or reinforce defective areas.
Are any areas of the scaffolding footing damaged or dangerously protruded, support horizontal member and wale loose? Are wall connections or connecting rod loose, knobs all in place?Are supports settled or slipped and materials that may fall placed?
d) Wall connection, connecting rod inspection, material on reinforced scaffolding, scaffolding footing, sheet shall be removed, and adequate measures shall be taken for materials that may fly or damage if heavy wind, rain or snow is expected.
3) Steel pipe scaffolding handling and storing
a) Cautionary items for steel pipe handling and storing shall be as the following.
Steel pipes, when transporting or moving up and down, shall be carefully handled to prevent transformation, failure and damage, and throwing shall not be performed.
b) Auxiliary materials and equipments shall be kept from loss or damages by utilizing adequate containers. Loosen 1 first when disconnecting connections, and some parts shall stay tight and loosened to prevent damages.
d) Perform material inspection to repair transformed or damages ones after dismantlement, and recoat paint layer peeled areas prior to storage. Dismantled materials shall be stored indoors to prevent decay. Storage shall have minimum moisture, and the materials shall not be placed directly on wet concrete or soil.
f) Heavy materials shall not stocked on top of steel pipes, use protective fences, limit stocking height to 1.5 m and install wedge or supports to prevent collapse. Use frames or ties if storing steel pipes upright. Steel pipes shall be sorted depending on their length, diameter, material and connecting accessories when storing.
4) Prefabricated scaffolding
a) Prefabricated scaffolding is the most widely used in main scaffolding type, highly resistant to buckling, easy assembling and dismantlement, and superior in safety, economy and workability. Prefabricated scaffolding is composed of column frame, intersecting strut, belt frame, square column joint, hardware, bracket, wall connecting hardware, etc.
b) Prefabricated scaffolding assembly and structure underlying support hardware and sleeper: To prevent slippage and settlement, install underlying support on top of sleeper and fixate.
c) Hoistway: Install vertical hoistway inside scaffolding, and install fabricating stairway or ladder for passages.
d) Wall connection : Firmly connect with connecting hardwares per 6 m vertical and 8 m horizontal.
e) Railing installation : Top railing from (H:95cm to 115cm), middle railing (Half of Top Rail).
f) Main frame interval : If the entire height exceeds 20 m, main frame height and interval shall be less than 2 m and 1.8 m.
g) Strut: Install intersecting struts in between main frames.
h) Scaffolding height : limit to within 40 m.
5) Miscellaneous
a) Receive training from the work supervisor, and perform work as directed by the supervisor prior to scaffolding fabrication. A supervisor shall remove defective products by inspecting steel pipes and other parts prior to work commencement.
b) Steel plates or supports shall be used on the part that comes in contact with the ground, and shall be adjusted to prevent severe height differences. Install reinforcements to support as needed to prevent transformations. Install struts in between supports, and install horizontal members on the top floor and within 5 floors from the top (main frame).
c) Completely tighten materials, plate connecting pins, joiners and fixing pins. Install wall connections with sufficient supporting strength against compressive force or connecting materials on scaffolding.
d) If the wall connections are composed of tensile and compressive members, the intervals shall be within 1 m. Supporting columns shall be installed within 10 m towards wale direction, if the length towards wale direction is less than 4 m and the height is greater than 1 0 m.
6) Scaffolding use and management
a) The items to care for regarding the scaffolding use and management are as the following. Vertical loading limit for 1 support is <2,500 kg for height greater than 1.7 m and <2,000 kg for height range of 1.93 ~ 20 m if the support is to be installed on solid foundation such as concrete.
b) Unnecessary materials for work shall not be placed on scaffolding, and measures shall be taken to prevent fall if inevitably placed. Unnecessary materials on top of scaffolding shall be cleaned up in advance. Use elevating facility when moving up inside scaffolding.
c) Inspect scaffolding every day to reinforce defective areas, and repair/ reinforce. Are there any protruded areas on scaffolding footing or damages, supports or connections on supports loosened? Are transformations present on support, horizontal steel pipe and strut connections, wall connections or connecting rods loose, railings shaky or broke off, supports settled or slippery and materials with possibilities of fall placed?
d) Take measures to reinforce wall connection or connecting rod, remove scaffolding footing and prevent material fall or scaffolding footing damage if heavy wind is expected. Transformed, damaged, uncoated ones shall be repaired after dismantlement. Store materials indoors to avoid rain if possible. Storing area shall be free from moisture, and shall not be placed directly on earth. If storing upright, connecting parts and main parts shall not be damages, and keep contaminants and impurities from entering the pipes.
7) Movable scaffolding
a) Movable scaffolding refers to scaffolding in a tower form with work place on the top and wheels on the bottom, and is also known as a Rolling Tower. Heights may be easily adjusted as it is a framed structure, easily movable with manpower, hence widely used for work indoors. Movable scaffolding is generally composed of fabricated frame, wheels, ladders, elevating facilities and protective railing facilities.
b) Movable scaffolding fabrication and structure
Railing installation : Top railing (H:95cm to 115cm}, Middle railing (Half of Top Rail)
Work footing : Work footing shall have width greater than 40 cm, thickness greater than 3.5 cm, and shall be tightly placed over the entire area.
Elevator facility: Attach elevation facility for use (>30 cm width, <40 cm interval)
Installation height: Less than 4X of minimum length of the bottom.
c) Maximum loading capacity indication : Indicate maximum loading capacity and the person in charge of use loading capacity may be calculated from the following equation in relation to scaffolding bottom area (A) – Loading capacity for A 2:2m = 250kg, Loading capacity for A< 2m = 50 + 100 xA
d) Wheel rolling stopper : Attach wheel stopper (Stopper) to prevent sudden scaffolding movement. Rope : When ascending or descending materials or equipments, use a sack or a rope.
Fall preventing block: Install with 10 cm height to prevent material or equipment fall. Work footing shall be closely placed on the entire area. Connecting and intersecting areas shall be firmly connected.
e) Cautions when working Perform work under work Owner’s command.
The scaffolding shall never move with workers on board and sufficient manpower shall be placed when moving scaffolding. All materials and equipments placed on the footing shall be removed in advance when moving scaffolding. Bottom holes and overhead obstacles shall be inspected in advance when moving a scaffolding, and sufficient manpower shall be placed.
f) Moving scaffolding technical procedure
Loading capacity for planning shall be of the following depending on the work floor area.
If A ≥ 2m 2 , W = 250kg
If A< 2m 2 , W = 50 + 100 xA
A and W shall represent the following value from the above equation.
A : Work floor area (unit : m)
W : Loading capacity (unit : kg)
The above loading capacity shall be attached on visible areas.
g) Height and caster interval from the wheel to work footing, leg wheel configuring outer frame when moving and main frame interval shall be of the following equation (H < 7. 7 L – 5).,
H and L shall indicate the following value regarding the equation.
H : Height from the wheel to the work footing (unit: m)
L : Main axis interval of the wheel (unit : m)
8) Hanging scaffolding (Movable)
a) Hanging scaffolding refers to footing that can transport simple objects or workers with wire ropes or steel materials hanging from the top. Hanging scaffolding fabrication and structure Wire ropes or chains shall be of good quality without defects, 1 strand of element wire cut more than 10% or entangled up and down shall not be used.
b) Wire rope diameter reduction greater than 7% of nominal diameter shall not be used. Chains elongated greater than 5% from manufacture, cross sections of the rings transformed greater than 10% and cracked objects shall not be used. Connect the ends of the fixing wire ropes to firmly fixed object.
c) Work footing width shall be greater than 40 cm, attached without gaps and the footing material shall be attached to prevent fall or bend. Railing with 105 cm height or greater than 75 cm shall be installed. Toe Board greater than 10 cm height shall be installed around the footing. Indicate load capacity limit.
d) Hanging wire rope and common joist safety factor shall be greater than 10, and chain / hanging hook safety factor shal be greater than 5. Cautionary items when working Install separate safety rope for each person. Safety belt and safety hat shall be mandatorily worn, and equip safety rope before stepping onto the foot plate.
e) Work shall not be performed outside the handles. Ladders or step plates shall not be placed on foot plates when working. If using on roads, signalman or supervisor shall be placed, and install traffic and guiding signs to limit by passer access. Work rod shall maintain horizontality when elevating and worker overloading is strictly prohibited.
9) Hanging scaffolding (Fixed)
a) Hanging scaffolding refers to the scaffolding to make working foot plate for rivet or bolt work by attaching to the main steel frame. Hanging scaffolding shall not be movable up and down, and special attention shall be paid to safety when fabricating.
b) Hanging scaffolding fabrication and cautionary measure when working softened #8 wire is the most widely used hanging steel wire (4 wound strands) with the factor of safety of greater than
8. If using rebar as a hanging material for hanging scaffolding, nominal diameter shall be greater than 19 mm.
c) Short pipe shall be positioned at 1.0m~1.5m, and shall not exceed 2.0m. Overlapping connection of the column shall be approximately 1 m. More than 4 scaffolding foot plate shall be placed in a line, and shall be precisely mounted on 2 or more columns.
d) Main connecting part shall be precisely fixed with #8 wire. Ladder with foot plate length greater than 30 cm and width less than 40 cm shall be installed for elevating facility. Protective facility shall install 90 cm high railing and greater than 10 cm high balance rail or cover steel mesh.
10) Other scaffolding types
a) Saddle scaffolding Installation height: Vertical height shall be less than 2 m when installing.
Work foot plate: Sufficient area shall be secured and more than 3 points shall be fixed.
Activity prevention : Ladders shall be prevented from activity of splitting. Protrusion length :
shall be within the range of 10~20cm, and work is prohibited near protruded area. Installation location : Shall be installed on a flat foundation, and use is prohibited near open duct area with dangers of falling.
b) Splitting scaffolding Installation height: Vertical height shall be less than 2 m when installing. Top footplate: Install with greater than 30 cm horizontal length and 20 cm width.
Step: Greater than 30 cm width, less than 40 cm vertical distance between steps, and non slippery material with width greater than 5 cm.
c) Slippage protection device : Square columns of the scaffolding shall be installed with non slippery material on a flat place. Installation angle square vertical angle less than 75°, horizontal angle less than 85°. Activity prevention measure firmly fixes ladders to prevent complete splitting.
d) Temporary slope Inclination angle and slippage railing slope inclination angle shall be within 30° , and slippage railing interval shall be as the following table.
e) Railing rod : Top handle greater than 90 cm on the left and right of the passage, and install
medium rod at 45cm. Supporting column, install every 2m horizontal distance. Slope width 75cm Landing : Install per 7 m height (if slope height exceeds 8 m), wood shall be of Douglas fir, etc.
or equivalent.
f) Slippage prevention device shall be installed if the slope exceeds 15° slippage prevention device may not be installed if the slope does not exceed 15°, but straw bags or sandbags shall be laid
on the floor for work for rainy or snowy weather. Railings shall be installed at height greater than
90 cm if the slope width is greater than 40 cm. Toe board shall be installed on both sides of the floors if the railing height is greater than 85 cm.
11) Movable ladder
a) Support : Step plate intervals shall be 25~30cm equally throughout. Ladder width shall be greater than 30 cm, and length shall not exceed 6 extended ladder length: Minimum 1 m extension from the rest or access point.
b) Conduction prevention device: Fix top and prevent conduction at the bottom to prevent ladder conduction. Installation angle : 75° with horizontal is adequate. (Fix with a fixing device as the ladder would fall if installation angle exceeds 75°)
SAFETY CONTROL
1) Subcontractor Safety Personnel shall carry out the safety site inspections to ensure that safety requirements laid out in the Safety Management Plan and General Instruction of Client CompanyClient Company & Scaffold Safety Handbook (SSH) are followed during the execution of works.
2) All person involved in scaffolding works must be provided with and use the necessary PPE and as a standard each person shall wear a Safety Helmet and Safety footwear, and etc. The requirement for personal protection equipment shall be approved by Client Company.
a) All personnel will be issued with the following personal Protective equipment and must be worn at all times.
• Safety Helmet
• Safety Shoes
• Safety Glass
• Safety Vest
• Cover All
• Fully Body Harness
3) Confined Space Entry:
a) No one may enter without specific approval and a current work permit prior to enter any deep excavation. The safety equipment is required.
b) No new activity shall be introduced into a confined space without the permission and signed approval of the permit to work issuing authority.
c) Subcontractors shall not enter or commence work in any deep excavation and other enclosed space until a valid permit to work has been issued. Where subcontractor operations may result in a dangerous atmosphere arising during the work activity.
4) All personnel involved in mass concrete works shall have to undergo Safety Training for TSTI & PTW being conducted by HSE Department.
TOOLS and EQUIPMENT
1) All tools that are recommended by the scaffolding manufacturer shall be used during scaffold erection and dismantling.
2) All of tools and equipment e.g. hand and power tools, slings etc. require special attention and protection for their use and guidelines for storage.
3) All damaged, unsafe or defective tools will be marked, tagged as Unsafe or with a Red paint and taken away from operation to assure that no one will use such tools on the job.