| Suspension bridge's stress characteristics made it highly demanding the accuracy of the final bridge formation.Suspension bridge main cable materials generally had: steel wire rope,steel wire,parallel wire bundles.Among them,the elastic modulus of steel strands and parallel steel strands was stable.The test showed that the elastic modulus of the steel wire rope increased with the increase of the tensile force within a certain range.This caused the elastic modulus of the wire rope to be less than the bridged value under the condition of the air cable.If the influence of the elastic modulus was not taken into account,the main cable shape would be much lower than the requirements of the design line shape after the bridge,and the resulting error cannot be remedied.In addition,the cross-sectional area of the main cable would gradually decrease as the tension of the main cable increased.In this paper,the influence of the non-linearity of the elastic modulus and the non-linear cross-sectional area of the main cable material on the main cable shape would be analyzed.However,there was no complete calculation scheme or commercial software available yet for calculating the main cable shape analysis considering the non-linear change of the elastic modulus of the main cable.Therefore,this article needed to write related software by itself,and then used self-compiled software to conduct relevant analysis of the research content.The main work involved in this text was as follows:1.Detailed derivation of the main cable alignment formula based on the catenary analysis theory.And using the theory of segmental catenary to derive and calculate the main cable's bridge shape,cable force,elongation of the main cable,no stress cable length,cable saddle pre-bias,cut arc difference,empty cable shape,and air cable status.The important construction data such as the location of the lower clamped.2.The influence of the non-linear variation of the main cable cross-sectional area and elastic modulus on the main cable alignment was explored,and the relevant correction algorithms and calculation formulas were obtained.3.Using the C# programming language to write the relevant suspension bridge calculation software,and compared with similar software verification.On the premise of ensuring correctness,the program was optimized so that it could accurately calculate the main cable shape when considering the nonlinear change of the elastic modulus of the main cable.In order to increase the value of self-programming programs,the program was further upgraded to computer software that was versatile,easy to use,and had a good graphical interface to facilitate more people's reference.4.Based on the actual construction data of Songpo Bridge,the correctness of the revised calculation plan and the self-programming procedure was verified,and the preliminary conclusions on the need for proper correction of the empty cable shape and the pre-deviation were obtained.5.Comparison of the empty cable shape data of Songpo Bridge considering the nonlinear change of the main cable's elastic modulus and the empty cable data(ie,design value data)of the conventional algorithm,and found that the two had significant differences,and the actual construction data showed that the calculation results of the self-programming program were basically the same as the actual situation.6.Keeping the Songpao Bridge's constant load concentration and the ratio of the span ratio unchanged.After modifying the span of the Songpo Bridge,used the selfcompiled software to calculate again.The preliminary conclusions that had been drawn from the study are applicable to suspension bridges with different spans.In this process,further practical conclusions of more universal value were drawn. |
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