Research And Application Of Fasener-type Steel Tubular High Formwork Support

With the highly development of urban and rural economy, high formwork support system has been more and more extensively applied to the cast-in-place concrete structure. While high formwork support system of Steel tubular scaffold with couplers, a style of frame system, is mostly widely used in China recently. However, because of the uncertain and unsafe factors during designing calculation and practical building of this frame, collapses of high formwork support system frequently take place, and meanwhile seriously affect the safety of construction and the performance of building.Presents design method is according to "Technical code for safety of steel tubular scaffold with couplers in construction" JGJ130-2001 to carry out, which has a certain limitation, because it only takes the stability of one step in a single pole of the support system into consideration, but fails to think over the mechanism effect of horizontal pole to the bearing capacity of vertical pole in high formwork support system.This paper analyzed and discussed several design and calculation methods. Through studying and analyzing applicability of the assumption of calculation model for the common formwork support in the high formwork support, the effect of joint constraints to the pole stability, and the effect of space bar members to the stiffness of fame body, obtained the conclusion that horizontal poles and bridging have the obvious regulatory effect to the axis force of vertical pole. Meanwhile, the effects of different connection ways of poles and concrete placing route to the stability of the frame body were also studied.In this paper, through strengthening joint constraints of vertical poles by the way of construction measures, made the mechanical analysis model of high formwork support accord with one step vertical pole's stable, thus stability calculation of the high formwork support can be transformed into the stability calculation of one step in a single pole of the support system.According to the analysis, to apply the analytical results to the practice, and continuously testify and perfect the theory in construction practice. It also can provide an available reference to the other construction projects.