[Chapter 1] Section 2 Scaffolding Material, Structure, and Assembly Drawing②

2 Prefabricated scaffold②

(4) Example of a handrail presetting construction method

・This is a method in which handrails or handrail frames that can slide up and down along the footings of the building frame, etc., are preset in advance from the work floor one level below the topmost platform to the end of the work floor, before the work floor such as a floor ledger form is installed on the topmost platform of the scaffold. When the work floor is removed, the handrail presetting equipment at the end of the work floor is left in place.

・The preset handrail is a piece of equipment that can be attached to or removed from the top level by sliding up and down on the work floor one level below the top level, and is generally installed only on the top level.

・This is a method in which stationary handrails or handrail frames are installed from the work floor one level below the topmost work floor before the work floor is installed on the topmost level of the scaffolding, and they are installed at the edge of the topmost work floor in advance of the scaffold assembly.When the work floor is removed, the stationary handrail equipment at the edge of the work floor is left in place.

・Stationary handrail equipment can be attached to or removed from the work floor one level below the topmost level, and is generally installed on one side of all levels of the scaffold.

・This method is based on a scaffolding system for presetting handrails. With prefabricated scaffolding, etc., which are permitted to be exempted from the regulations for steel pipe scaffold members and fittings, a member that functions as a handrail can be installed at the edge of the work floor before the work floor is installed on the topmost level of the scaffolding, from the work floor just below this topmost level. Moreover, when the work floor of the topmost level, the member functioning as a handrail can be left at the edge of the work floor.

 

 

(5) Dismantling of prefabricated scaffolding

Serious disasters, including public accidents, can occur during scaffolding dismantling work.

1.Review examples of past disasters, such as the collapse of scaffolding during dismantling work after removing wall joints ahead of schedule, dropping materials after removing mesh sheets, and being hit by dropped materials when unloading materials by hand caused by up-and-down work.

2.Keypoints in preventing disasters when dismantling scaffolding

・Conduct risk assessments during the work planning phase

・Prepare work plans based on the results of risk assessment

・Disseminate the work plan to the workers concerned

・Appoint work supervisors when dismantling scaffolding of 5 m or more in height and encourage them in their duties

・Provide special education for workers engaged in dismantling scaffolding

・Secure a work floor at least 40 cm wide when dismantling scaffolding

・Install equipment for the safe installation of fall prevention equipment

・Ensure thorough use of fall prevention equipment among workers

・Use lifting ropes, lifting bags, etc. when lowering materials, instruments, tools, etc.

・Implement measures to prevent falling of materials, instruments, nets, etc., by installing nets, etc.

・Implement measures to prohibit entry except by related parties

3.To minimize work at the top level during assembly, etc., which has a high rate of fatalities, efforts should be made to adopt ” rolling scaffolding,” which do not require assembly and dismantling work at high places, and “large assembly and dismantling methods,” which require much less assembly and dismantling work at high places than conventional methods.