Study On The Safety Evaluation Method Of Bridge Steel Tube Falsework Systems

The steel tube modular falsework system is widely used in the bridge construction with its simplicity and good performance as a whole. While the improper control of the strength status of falsework system in the application will induce the accidents of falsework collapse and the personnel casualty, which brings the magnitude economic loss. On the basis of the model experiments and the theoretical analysis of the falsework system, the dissertation builds up a mechanic model of the bridge falsework system, and develops a program on the internal force analysis and stability calculation of falsework system, which realizes the change from the engineer's experience to the accurate design by computer. The chief achievements are as follows: The dissertation studys the application of bowl scaffold bracing system in the bridge construction, and summarizes the reasons of falsework collapse. By comparison of virtues and shortcomings between the various scaffolds which are usually used in the bridge construction, the dissertation also gives the basic principle to choose the new type scaffolds bracing systems in the living projects and the building scheme of scaffold system. According to the calculated model and the locale situation, the paper sets up the indirect experimental model, carrying on the indoor experiments under the simulating local situation, summarizing the damage process and characters of falsework model, analyzing the experimental data, proving the accuracy of calculated model, bringing forward the mechanical mechanism and damage model of scaffold bracing system. The dissertation gives the calculated methods of loads after analyzing the various loads acting on the scaffolds systems. According to the structure and the joint forms of steel tube modular falsework system, this paper also gives the stability and load capacity rule of scaffolds, setting up the mechanic model and puts forward the calculate methods of structural internal forces and stability. On the basis of the finite matrix shifting methods, this dissertation analyzes the internal forces and the stresses of bridge scaffolds numerically and develops the calculated program on the internal forces and stability of bridge scaffold by making use of the visual C++. Making use of the calculating program on the internal forces and stability of bridge scaffold developed personally, this paper carried on the calculation to the structure model and draws a conclusion that the calculating results are consistent with the experimental results, which validates the credibility of calculated model of scaffolds and the program. By the checking computations on a typical project, the paper is proved to solve the internal force analysis and stability calculation of steel tube modular falsework system perfectly, which heightens the stability of scaffold bracings and gives the assurance of safety during the construction of bridge falsework.