海外工程脚手架搭设拆除施工方案范本.doc

METHOD STATEMENT FOR SCAFFOLD ERECTIOIN & DISMANTLING1.0 INTRODUCTION :This procedure highlights the MMG work procedure for the erection & dismantling of scaffolds. Execution of the work shall be in accordance with relevant project specifications2.0 REFERENCES :ANSI A10.8: Scaffolding Safety RequirementsANSI A14.2: Ladders, Portable Safety Metal RequirementsASTM A53: Standard Specification for Pipe, Steel, Black & Hot Dipped Zinc Coated, Welded & SeamlessASTM A123: Standard Specification for Zinc (Hot-dipped Galvanized) Coating on Iron & Steel ProductsASTM A500: Standard Specification for Cold-Formed Welded & Seamless Carbon Steel Structural Tubing in Rounds & ShapesBS 1139 Part 1 Section 1.1: Specification for Steel TubeBS 1139 Part 2 Section 2.1: Specification for Steel Couplers, Loose Spigots and Base Plates for Use in Tubular ScaffoldsBS 2482: Specification for Timber Scaffold BoardsOSHA 1910.28: Safety Requirements for ScaffoldingsOSHA 1910.29: Manually Propelled Mobile Ladder Stands & Scaffolds (Towers)OSHA 1915.159: PERSONAL Fall Arrest /systems (PFAS)Saudi Kayan Safety Procedures ManualMMG Safety and Loss Prevention Program3.0 RESPONSIBILITY :3.1 Scaffolding Superintendent / SupervisorThe scaffolding superintendent/supervisor is responsible in overseeing overall scaffolding works in the project. He shall ensure that all scaffold foreman &and builders/erectors are properly trained and comply with the requirements of this procedure and Safety Manual. He shall ensure that all work permits were secure before the start of the job.3.2 Scaffolding InspectorThe scaffolding inspector shall inspect all scaffolds and ensure that these are safe to use and fully comply with relevant specifications and standards.3.3 Scaffolding EngineerThe scaffolding Engineer shall be responsible for the design and approval of all specialty scaffolds above 12 meters in height and inspection thereof.3.4 Safety SupervisorThe Safety Supervisor shall ensure that all workers are in compliance with the requirements of the Safety Manual. He shall check and ensure that all work permits (Elevated Work Permit & Scaffold Permit) are obtained and STAs (Safety Task Assignments) are implemented prior to the start of work. He is responsible for monitoring all scaffoldings for any unsafe conditions and make corrective actions where necessary. He will directly liaise with the scaffolding supervisors regarding the safety aspect of the on-going work4.0 KEY DEFINITIONS :4.1SCAFFOLD: A temporary elevated platform (base supported or suspended)and its supporting components used for supporting workmen, material or both. /types of scaffold covered on this procedure are tube and coupler scaffolds as defined below; Mobile Scaffold: A rigid scaffold assembly supported by casters that can be : manually moved horizontally. Tower Scaffold: A supported scaffold consisting of only four (4) posts connected together longitudinally with runners and bearers at right angles to each other, forming a square or rectangular tower Underhung Scaffold: A scaffold that is rigidly attached by scaffold tubes and load bearing couplers to an overhead structure directly above and having a work platform that can not be raised or lowered.4.2 FULL BODY HARNESS: A design of straps that may be secured about an individual in a manner to distribute the fall arrest forces over the tights, pelvis, waist, chest and shoulders, with means of attaching it to other components of a personal fall arrest system. (Note : Only full body harness with two lanyards and shock absorbing devices are accepted in the project).4.3 COUPLER : A component or device used to fix scaffold tubes together. Types of couplers include the following: Adjustable Coupler : A device used for connecting two tubes together at an angle other than 90 deg. Bearer Coupler : A device used for fixing a bearer to a runner, or to connect a tube used only for a guardrail to a post Check (Safety) Coupler: A right angle coupler added to a loaded joint on an underhung scaffold to give supplementary security against slip to the coupler carrying the load. End-to-end Coupler : A device used for externally joining two (2) scaffold tubes co-axially end to end. The steel divider is located centrally to ensure equal insertion of each tube. Girder Coupler : A device used for connecting a scaffold tube to a steel wide flange beam (I-beam). Girder coupler shall be used in pairs, one on each opposite flange. Right Angle Coupler : A load bearing coupler used for connecting two tubes together at right angles. It is critical component in the scaffold structure and must resist both slip and distortion.4.4 SCAFFOLD COMPONENTS : Base Plate : A steel plate providing a flat bearing surface with a spigot or a screw jack for distributing the load from posts. Bearer: A horizontal transverse scaffold number , that may support platform units, and which is supported by at least two runners connected directly to at least two posts. Brace: A rigid connection of scaffold tubing that holds one scaffold member in a fixed position with respect to another member to give the scaffold rigidity. Guys: Tension members (i.e., wire ropes) used between the scaffold and the ground, building, or structure to enhance the scaffold lateral stability. Hanger Tube: Vertical tube similar to and serving the same load-carrying purpose as posts, except that hanger tube s are hung from existing structure and loaded in tension. Ladder: A device used for climbing between levels of scaffolds. Outrigger: The structural members of a supported scaffold used to increase the base width of a scaffold in order to provide support for and increase of stability of the scaffold. Plank: An individual timber board or fabricated component that serves as flooring member of a platform. Post: A vertical scaffold tube that bears the weight of the scaffold. Raker: An inclined load bearing tubes that braces the scaffold against the ground. Runner: A lengthwise horizontal scaffold tube that extends from post to post, that supports the bearers and that forms a tie between the posts. Screwjack: A load carrying device used at the base of the scaffold to compensate for the variations in ground levels. Sill: A timber spreader used to distribute the load from a base plate to the ground. Tie Tube: A tube used to connect scaffold to a tie anchor point (i.e., box tie). Trapeze Tube: A horizontal scaffold tube measuring between 300 and 450 mm in length and installed at the lower portion of the hanger tubes approximately two feet below the runners. It used in erection, modification and dismantling of underhung scaffolds. It also serves as secondary support if the runner slips. Caster: A pivoting wheel, containing a wheel lock, which is attached to a vertical post of a mobile scaffold to allow for manual movement of the scaffold.5.0 ELEVATED WORK AREAS GENERAL REQUIREMENTS :5.1 FALL PROTECTION: Each person who could fall more than 1.8 meters shall be protected by a fall protection system. Fall protection system includes guardrail system s and fall arrest systems. Each scaffold craftsman shall continuously wear full body harness with a shock absorbing lanyard while erecting, altering, or dismantling a scaffold. If possible to do so, each scaffold craftsman shall properly anchor his lanyard. The lanyard should be anchored to the scaffold only if it is not possible to anchor to a stronger anchorage (including a lifeline).5.2 GUARD RAIL SYSTEM: Guardrail systems (consisting of toprails, midrails, toeboards and support uprights) shall be installed in all open sides and ends of elevated work areas (including scaffold platforms and stair landings) where a person could fall 1.8 meters or more. The top edge height of toprails or equivalent member on supported scaffolds shall be installed between 0.97 meter and 1.2 meters 38 inches and 45 inches) above the platform surface. When midrails, screen, mesh, intermediate vertical members, solid panels, or equivalent structural members are used, they shall be installed between the tope edge of the guardrail system and scaffold platform. When midrails are used, they shall be installed at the height approximately midway between the top edge of the guardrail system and the platform surface. When intermediate member are used, they shall not be more than 480 mm apart. Each toprail or equivalent member of a guardrail system shall be capable of withstanding, without failure, a force in any downward or horizontal section at any points along its top edge of at least 45.3 kilograms (100 pounds) for guardrail system installed on single-point adjustable suspension scaffolds, and at least 90.7 kilograms (200 pounds) for guardrail systems installed on all scaffolds.5.3 FALLING OBJECT PROTECTION: The area below the scaffold where objects can fall shall be barricaded and employees shal not be permitted to enter the hazard area. Toeboards shall be installed along all edges of elevated work areas (including scaffold platforms) more than 1.8 meters above lower levels, unless personal access to the lower level under the elevated work area is physically prevented. Toeboards shall conform to the following requirements: The vertical distance from the top edge of the toeboard to the level of the walking/working surface shall be at least 90 mm (3-1/2 inches). Wood toeboards shall be t least 26 mm (1 inch) thick. Teoboards shall be securely fastened in place along the outermost edges of the platform and have not more than 7 mm (1/4 inches) clearance above the working/walking surface. Toeboards shall be solid and capable of withstanding, without failure, a force of at least 23 kilograms (50 pounds) in any downward or horizontal direction at any point along the toeboard. Where tools, materials, or equipment are pile to a height higher than the top edge of the toeboard, paneling, or screening extending from the toeboard or platform to the top of the guardrail system shall be erected for a distance sufficient to protect the workmen below.5.4 ENTRY AND EXIT: A safe means of entry and exit shall be provided and used whenever elevated work area or scaffold platform is 0.6 meter (2 feet) above or below a point of access. Ladders, stairs/stairways, ramps, or walkways shall be used. Whenever the horizontal travel distance exceeds 15 meters (50 feet), each elevated work area shall have at two means of exit. A means of exit shall be provide at least every 30 meters (100 feet). When hook on and attachable ladders are used on a supported scaffold more than 10.7 meters (35 feet) high, they shall have rest platforms at 10.7 meters (35 feet) maximum vertical intervals.5.5 LADDERS: Hook-on and attachable ladders shall have a minimum rung length of 290 mm (11-1/2 inches) and shall have uniformly spaced rung with a minimum spacing of 420 mm (16-3/4 inches). Straight ladders and extension ladders shall be placed at a slope of 4:1, or straight ladders and extension ladders may be placed vertically if both side rails are rigidly attached to a supporting structure (i.e., scaffold) at the top, middle and bottom of the ladder. All ladders shall extend at least 1 meter (3.28 feet) above the landing of work surface. The bottom rung of ladders shall not be more than 610 mm (2 feet) above the lower level used to mount the ladder. Ladders shall have a minimum clear distance of 760 mm (30 inches) from the rung to the nearest projecting object on the climbing side. When unavoidable obstructions are encountered, the minimum clear distance maybe reduced to 610 mm (24 inches) if deflector plates are available.6.0 SCAFFOLD COMPONENTS REQUIREMENTS :6.1 GENERAL: The components used to assemble scaffold shall be inspected before each use and shall conform to the requirements of this section regarding materials, strength, dimensions and etc. Scaffold components manufactured by different manufacturers shall be intermixed unless components are compatible (fit together without mechanical force) and the scaffold structural integrity is maintained. Scaffold components manufactured by different manufacturer shall not be modified in order to intermix them. Scaffold shall be free from detrimental corrosion. Any scaffold component that is obviously damaged, excessively corroded, defective or does not meet the applicable codes and standards shall not be used. Scaffold components do not made dissimilar metals shall not be used together because of the potential of galvanic corrosion. Scaffold component shall be stored to prevent damaged.6.2 SCAFFOLD TUBING AND FITTINGS: Scaffold tubing shall be 48.3 nominal outside diameter. Scaffold tubing (for tube-and-coupler) shall be welded or seamless structural steel pipe fabricated in accordance with ASTM A500, ASTM A53, BS 1139, Part-1 and EN 10219 and shall meet the testing and inspection requirements of STM A500. Steel tubing for tube-and-coupler scaffolds shall be hot dipped galvanized in accordance with ASTM A123. Scaffold couplers shall be marked as conforming to either BS1139, EN74 or Client approved equivalent specification. Couplers maybe either pressed or dropped forged type and shall galvanized or zinc coated to resist corrosion. Scaffold components and fittings shall be installed as per manufacturers instructions. Girder coupler shall always be used in pairs.6.3 SCAFFOLD PLANKS: Scaffold planks shall be either solid sawn wood planks, laminated veneer lumber planks or fabricated planks. Solid sawn wood scaffold planks shall be either 2 x 10 inches, 2 x 9 inches, 38 x 225 mm or 50 x 225 mm. The wood planks shall be of scaffold plank grade and hall be certified by and bear the grade stamp of the West Coast Lumber Inspection Bureau, Southern Pine Inspection Bureau or other lumber-grading agency approved by the American Lumber Standards Committee. Solid sawn wood scaffold planks conforming to and marked in accordance with BS2482 are also acceptable. Laminated veneer lumber planks shall measure 38 mm thick x 225 mm wide or larger and shall have the words “PROOF TESTED SCAFFOLD PLANK” OR “OSHA” continuously embossed along both edges. Scaffold plank ends shall not be split more than 25 mm without metal bonding and even with bonding. Plank end shall not be split over 300 mm. Planks shall not be twisted from end-to-end or curled from side-to-side more than 13 mm. Planks shall be inspected for defects, including damaged, decay and wrapping prior to each use. Planks shall be properly stacked, off the ground on a suitable foundation. Where the height of the stack exceeds 20 planks, measures shall be taken to tie or bond succeeding7.0 REQUIREMENTS COMMON TO ALL SCAFFOLDS :7.1 CAPACITY: Every scaffold and scaffold component shall be capable of supporting without failure, its own weight and at least four (4) times the maximum intended load (live load) applied or transmitted to it. All scaffolds shall have a specified load rating corresponding to the maximum intended load of either light duty, medium duty or special duty. For design, the maximum intended load (live load) shall be taken as of scaffolds load rating. Scaffolds and scaffold components shall not be loaded in excess of their load rating.7.2 FOUNDATIONS: Foundation shall be sound, rigid, and capable or carrying scaffold weight plus the maximum intended load without settling, or displacement. Unstable objects such as barrels, boxes, loose bricks or concrete blocks shall not be used to support scaffolds, planks or timber sills. The ground or floor on which scaffold stands shall be carefully examined for its load bearing capacity. Sand or made-up ground may need compaction to ensure there are no cavities. Timber sills (sole boards) at least 225 mm wide by 38 mm thick shall be use to spread the load on sand, made-up ground, asphalt pavement, wooden floors and other soft or slippery surfaces. The ground beneath the sills shall be level and compact. A sill shall extend at least two posts, unless not feasible because of un-even or sloping ground. In this case, sills under individual posts shall be at least 765 mm long. Scaffold planks shall not be used as sills. All scaffold posts shall be pitched on steel base plates at least150 mm x 150 mm x 6 mm thick. For special scaffolds, these base plate shall be designed to support the maximum scaffold post load. Screwjack shall be used to compensate variations in ground level. Screwjacks shall not be adjusted more than two-thirds of the total length of the threaded section. Screwjacks shall be used and loaded in accordance with manufacturers specifications.7.3 FOUNDATIONS: Scaffold posts and frames shall be erected and maintained vertical and plumb and vertically braced in both directions to prevent swaying and displacement. Plumb ness should be check using spirit level, plumb bob or using vertical lines on an adjacent building or structure. Supported scaffolds with a height to the upper most plank level that is over four times the minimum base dimension shall be restrained from tipping by ties, guys, outrigger frames or equivalent means. Upper section or stepped scaffold shall not have a height over four times the width of the scaffold at the base of the section, unless ties or guys are properly installed to ensure stability.7.4 HORIZONTAL MEMBERS: For system and tube-and-coupler scaffolds, every line of posts shall have ru