Study On Safty Evaluation Method Of Highway Bridges Based On DHGF Theory

Recently safety evaluation of highway bridges is becoming a hot topic increasingly. Safety evaluation on the existing highway bridges is an important prerequisite for judging bearing capacity and adopting the appropriate measures of conservation, maintenance, consolidation or reconstruction in time. It is also an effective way of reducing accidents. Objective and accurate safety evaluation of bridges can make the fee of maintenance applied reasonably. At the same time it can avoid major economic losses and bad influence on society caused by structural damage.Based on summarizing the research achievement about existing bridges evaluation at home and abroad and combining the features of highway bridges, further study on safety evaluation methods for existing highway bridges is taken in this paper. First, on the basis of analyzing the common safety evaluation method of bridges deeply, the advantages and the disadvantages of every method are compared, and then DHGF synthetic evaluation method with greater scientificity and superiority is introduced. The DHGF synthetic evaluation method is a judgement theory combined with Delphy method, Analytical hierarchy process method, grey clustering theory and fuzzy judgement theory. It completes some calculation processes such as determining the relative significance of index, computing combinational weight, establishing the grey evaluation vector and matrix and so on. Accordingly the final evaluation results are achieved. Second, starting from the safety evaluation of bridges the DHGF comprehensive evaluation method is applied in the bridges bearing capacity appraisal on the basis of existing evaluation methods. The DHGF evaluation model of bridges safety evaluation is established and the safety evaluation grades and indexes scoring standards are formulated. Finally, relying on the real project DHGF theory is applied in the real highway bridges safety assessment, and the evaluation result matches that of technical state evaluation based on specifications and loading test well. So the scientificity, veracity and maneuverability of the DHGF evaluation method is proved.The main innovation sparkle of this paper is firstly applying the DHGF evaluation theory in the field of bridges evaluation and establishing corresponding evaluation grades and indexes scoring standard. The procedure of DHGF bridge safety evaluation is compiled by using VB computer language, which deduces the impact of the errors and inaccuracies for the evaluation and realizes the accurate evaluation for the highway bridges safty.