3．事故原因分析
　　总的来说，造成脚手架、模板倒塌的主要原因是材料质量、方案设计以及施工管理存在问题。
　　3.1材料问题 
　　脚手架主要是钢管和扣件。按标准要求，用于扣件式脚手架的钢管应采用外径48mm，壁厚3.0-3.5mm的焊接普碳钢管。目前，许多网管生产厂家为了抢占市场，低价竞争，生产的钢管壁厚仅为2.5～2.75mm，与用户结算仍按壁厚3.5mm的理论重量计处。由于钢管租赁是按长度计价，不是按重量计价。因此租赁单位愿意购买壁厚2.5～2.75mm的低价钢管。但是，这种钢管的惯性矩损失20％左右，如果经过多年施工应用后，钢管锈蚀使壁厚减薄，钢管惯性矩还要减少，所以，今后这些钢管将是脚手架安全的隐患。　江苏南通如皋市脚手架厂  刘经理   章经理
3 the cause of the accident analysis
in general, scaffolding, formwork collapse caused the main reason is thequality of materials, design and construction management problems.
3.1 problems of materials
mainly steel pipe and fastener scaffold. according to the requirements of standards, for the fastener scaffolding steel pipe should be used inoutside diameter 48mm, wall thickness 3.0-3.5mm welded carbon steel pipes. at present, many network manufacturers in order to seize the market, price competition, the production of steel pipe wallthickness is 2.5 ~ 2.75mm, and user accounts still according to 3.5mm wall thickness of the theoretical weight gauge. because the steel pipe lease is according to length of valuation, not by weight.the rental unit is willing to buy a wall thickness of 2.5 ~ 2.75mm cheap steel pipe. however, this kind of steel tube moment of inertia of the loss of about 20%, if after many years afterimplementation, steel tube corrosion of the wall thickness of steel pipe, moment of inertia and reduced, so, the future of these pipes would be scaffold safety hidden danger. jiangsu nantong rugaocity scaffolding factory liu jingli chapter manager

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大丰市安大脚手架厂
刘生
15371719638
江苏省如皋市庆余东路66号