Research Of Safety Control In Falsework Based On Evidence Theory

ABSTRACT:Falsework is not only an essential part in construction of civil engineering but also an extremely important temporary facility. Recent years,a lot of accidents occurred during construction due to falsework collapses caused. The safety of falsework construction is not optimistic. The paper research into falsework accidents caused is rewarding. The research works are as follows:1. According to collecting and detailedly analyzing the data of falsework accidents in recent four years, the authors summarize the direct and indirect reasons of falsework accidents, and then carry out the finite element analysis to the main structure factors. The present results demonstrate that bridging, thickness of steel tubes, extension of vertical pole have significant effects to Ultimate bearing capacity;2. Based on early research of conflict theory, a modified method of evidence combination is proposed. A calculation flow chart of improved evidence synthesis method is designed. Program frame of DS evidence theory, Jousselme evidence distance, and their algorithmic routine is compiled. Compare to the relevant examples, it is found that the new method of evidence combination is more effective;3. Based on DS evidence theory, a safety assessment method of falsework is proposed. The evaluation procedure is given in detail. And it introduces corresponding numerical examples, both single-player and multiplayer comprehensive evaluation to falsework is making by the modified method of evidence combination. Finally, the method of safety evaluation is improved. Numerical examples show that comparing to comprehensive probability method, the results denote that the evidence theory is more suitable to take in account the unknown message in experts’ evaluation; the evidence theory can improved discriminant clarity, which form comprehensive evaluation by combinating the evaluation of several experts and reduces the degree of uncertainty, compare to an expert; The improved evaluation method is more reasonable and has better convergence of the Safety evaluation, which expands the expert evaluation set;4. A method that takes the combination of experts’decision to get integrated decision-making is proposed,which is based on evidence theory. It creats the recognition framework of decision, designs basic trust acquisition method, takes Information fusion by the method of evidence combination, and gives the cause of the accident decision. Numerical examples show that this method can synthesizes the decision of the integrated experts, describe the uncertain and unknown information in the system, and arrive at a conclusion the probability of all kinds of accident cause;5. According to the cause of the falsework accidents, a safety control method, which is in combination with safety assessment method and the cause of the accident decision method and refers to the related reference is proposed.