Scaffold is the first barrier to ensure the safety of workers in construction, and it is the basic tool for high-rise construction
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Recently, several scaffold collapse accidents happened suddenly, which caught people off guard
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This is largely because the engineering personnel do not understand the key points of scaffold safety control
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On January 12, 2021, scaffolding collapsed at a construction site in Kai Tak Development Zone, Kowloon, Hong Kong! At about 8:00 a.m
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on January 9, scaffolding collapse occurred at a construction site in Hong Kong
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In the process of dismantling the external wall decoration scaffolding of three units located at No
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1, North Lane 2, Dongfeng Road, Chengdu, the external wall scaffolding that had been removed from the 5th floor to the 1st floor collapsed when it was removed to the 2nd floor
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There are many reasons for the collapse accident of Chengdu scaffold, such as the nonstandard erection of scaffold, the overweight load on the scaffold in construction, the random removal of tie or stress bar, etc., which may cause safety accidents
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Therefore, it is very important to strengthen the safety construction management of scaffold
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All kinds of precursors often appear in production safety accidents, which can be found and handled in time
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For scaffolding, how to distinguish the precursor of the accident in order to avoid casualties? 01 scaffold vertical collapse (1) early signs of vertical collapse: the lower part of the scaffold and the long vertical pole begin to appear lateral arch deformation, which is visible to the naked eye but easy to ignore
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(2) The medium-term sign of vertical collapse: the vertical poles begin to appear obvious multi wave arch deformation from the bottom to the top, and at the same time, there will be signs of damage at the scaffold nodes and connectors
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(3) The late signs of vertical collapse: abnormal sound of scaffold nodes and wall parts damage begins to appear, and some scaffold nodes and connectors will be seriously damaged
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02 local collapse of scaffold (1) early signs of local collapse: obvious bending deformation and damage of local horizontal bar and scaffold board of scaffold, and cracks or loose sliding at local connectors of scaffold, which are visible to naked eyes but easy to ignore
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(2) Medium term signs of local collapse: the damage characteristics of the early signs continue to develop, and the crack propagation or sliding of the connector is serious, and some joints begin to deform
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(3) Late signs of local collapse: the scaffold board and horizontal bar began to break or fall off, and the local frame began to deform seriously, accompanied by abnormal sound
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03 collapse of scaffold and multi-layer transfer trestle (1) early signs of collapse: the foundation of the scaffold standing on one side of the transfer frame begins to settle; the scaffold standing pole slightly collapses to one side of the transfer frame; there is initial tension and compression or shear deformation of the connecting wall parts
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(2) Medium term signs of toppling: the damage characteristics of the early signs continue to develop, and the upper part of the frame begins to shake
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When it is serious, the root of the upright pole will obviously separate from its supporting pad or position
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(3) Late sign of toppling: the upper part of the scaffold topples out sharply, accompanied by abnormal sound
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04 reinforcement method of finding signs with the increasing volume of building construction, the huge scaffold group is likely to have several kinds of security risks at the same time, and many accident signs are caused by some reinforcement measures are not in place
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What should we pay attention to? (1) Foundation settlement will cause local deformation of scaffold
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In order to prevent collapse or toppling caused by local deformation, the cross section of double bent is erected with eight shaped berm or cross bracing, and a group of vertical poles are erected every other row until the deformation area is discharged
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The lower foot of the eight shaped berm or cross bracing must be set on a solid and reliable foundation
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(2) If the deflection deformation of the cantilever steel beam on which the scaffold is based exceeds the specified value, the anchor point behind the cantilever steel beam shall be reinforced, and the steel beam shall be supported on the roof with steel support and U-shaped bracket
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There is a gap between the embedded reinforcement ring and the steel beam, which must be fixed with a horse wedge
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The steel wire ropes at the outer end of the hanging steel beam shall be inspected one by one and all of them shall be tightened to ensure uniform stress
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(3) If the scaffold unloading and connecting system is damaged locally, it shall be restored immediately according to the unloading and connecting method formulated in the original scheme, and the deformed parts and members shall be corrected
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Timely correct the deformation of scaffold outward tension, do a good job in rigid connection, and tighten the wire rope at each unloading point to make it stress evenly, and finally release the chain
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In order to avoid scaffold accidents, in addition to doing a good job of safety inspection, we should ensure that the scaffold erection meets the safety requirements, so as to avoid scaffold accidents to the greatest extent
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(1) According to the requirements of forming the basic frame unit, the scaffold should be erected row by row, span by span and step by step
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The scaffold around the rectangle should start from one corner and gradually extend outward, so as to ensure the stability of the erected parts
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(2) When the scaffold meets the structural layer of the wall connecting parts, the wall connecting parts shall be set immediately after the erection of the column, transverse horizontal bar and longitudinal horizontal bar
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(3) When erecting the column, it is not allowed to mix the steel pipes with different outer diameters, and it is not allowed to place the butt fasteners of adjacent columns in the same height, so that the staggered distance meets the structural requirements
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(4) The horizontal support and cross bracing shall be set up simultaneously with the vertical and horizontal horizontal bars and columns, and the distance between the center line of the fasteners such as the horizontal support and cross bracing and the main node shall not be greater than 150 mm
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(5) The distance between the wall end of the horizontal bar of the double row scaffold and the wall decoration shall not be greater than 100 mm
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The above is what Huasheng Tiancheng shares with you today
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As long as you master the key points of scaffold safety construction, I believe that scaffold accidents will be prevented in the future
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Near the end of the year, Huasheng Tiancheng reminds you to pay attention to safety! As a kind of scaffold with high safety factor, the coil type scaffold is superior to the traditional scaffold in terms of scaffold material and connection form
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Huasheng Tiancheng turnbuckle scaffold has been widely used in high formwork support system, and its safety and economy have been recognized and affirmed by more and more construction units
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Beijing Huasheng Tiancheng, an integrated service provider of building formwork, integrates the production, scheme design, leasing and professional construction of turnbuckle scaffold
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It provides customers with a package of solutions for formwork engineering
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With a good reputation of safety, efficiency and zero accident, it has completed hundreds of national large-scale projects and gained high praise and trust from partners
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The scale of coiled scaffold is expected to exceed 170 billion yuan in 2027! Implement the national strategy, Huasheng Tiancheng participate in the construction of China (Zhejiang) pilot free trade zone! Scaffolding erection, demolition, acceptance of the 24 criteria, please put away! See how Huasheng Tiancheng scaffold escorts the construction of Hunan Meiyijia project, and the National Health Commission advocates celebrating the new year on the spot! How to prevent epidemic in construction site? Zanhe is watching here.
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