Study On Safety Of Formwork Supports System Of Long-span Prestressed Concrete Beam Used In Hengyuan Ginza Of Gu Yang Mine

With the general development of construction technology，it has been the trend that theupper prestressed concrete structure should be made before the lower prestressed concretestructure establishes prestressed, thus multilayer formwork supporting system has beenapplied to make construction more efficient, and lots of load pass down, leading to thedemand for the formwork supporting system which as a temporary structure is more strict.To make sure the construction safety of multi-story prestressde conctete structure formworksupporting system. The paper makes the following research:Based on the formwork supporting system of three layers large span prestressed beamin hotel building project of Hengyuan ginza, the article summarizes and analyzes the failtureof the template trestles by activity based classification, discovering the main causes andexisting problems that lead to the instability of the trestles is the design and constructiontechnology of templates supports. According to that, the paper firstly proposes the loadanalysis of multi-level prestressed concrete beam formwork supporting system. The anti-overturning, pole vertical deformation, stability calculation of supporting system arediscussed, and then, raises the design method of supporting system that analysis with thefinite element model which set up by SAP2000. At the same time, simulates the effect offormwork supports system with different height to width aspect ratio(H/B) of formworksupporting system to provide a basis for design. Secondly, the paper discusses the verticalpole’s and side restraint’s building methods of formwork supporting system, in order tomake reasonable technical measures, the affection of horizontal on the internal force andnodal displacement of the formwork supports system has been simulated. Research showsthat:(1) In virtue of SAP2000modeling analysis has considerd the integrity space offormwork supporting system, making the calculation result less than the theoretical result,and its calculation result only for the theoretical calculation of75%. The bucking strength offormwork supporting system changes linearly with H/B while the H/B from1to6, and when a H/B is6, the bucking strength of formwork supporting system is almost40%lower than aH/B is1.(2) The bucking strength of formwork supporting system increased with theincrease set number of spanned of the pole while the span erection of formwork supportingsystem is certain. And the bearing capctity of the supporting system which set lateralrestraint form the bottom first step of supporting system by the level of two-step and thevertical three-across has improved, then the bucking strength of the supporting system whichhas set up the lateral restraint form the first step in the bottom is16%higher than the thesupporting system set up the lateral restraint form the fifth step, and its deformation issmallest.(3)When a horizontal load has acted, the formwork supporting system would toppleover along the direction of the horizontal load, and with the increase of horizontal loading,the displacement of formwork supporting system would be increasing.At the end, according to the study, the article explains the design calculation methodsand measures of construction of formwork supports system through a project. It can providean available reference to the other projects of safety construction in the forthcoming years.