Research on the Design Safety Factor of the Supporting Falsework Considering the Installation Gaps

Abstract

In order to fully consider the influence of the top installation gaps on the axial forces of the vertical poles during the erection of the supporting falsework, a finite element model of the 25 vertical poles considering the top gap element was established based on a large number of field measured data of the top installation gaps. The size of installation gap in this model considered two kinds of distribution: uniform distribution and random distribution. The uniform distribution value of the gap was 1.4mm and the value interval of the random distribution was [0, 0.7] and [0, 1.4]. The numerical simulation results showed that the axial forces of the vertical poles were uniformly distributed without considering the top installation gaps of the vertical poles. When considering the top gaps of the vertical poles, the calculation results of the two distribution types showed that the axial forces were non-uniform distribution and the maximum axial force of the pole increased by 2.3 times. Besides, according to the measured test data of the axial forces of a certain engineering project, the distribution law of the vertical pole’s axial forces in the actual project was also analyzed and the results showed that the maximum value of the axial force was about twice the minimum value. Since it is impossible to ensure that the elevations of the top of the vertical poles are exactly the same during the actual erection of the falsework, the top installation gaps are inevitable. When designing the bearing capacity of the falsework, the influence of the top installation gaps on the axial forces of the vertical poles should be fully considered. The recommended safety factor range of the bearing capacity of vertical pole is 1.7-2.1.