Quantitative Study On The Structural Geometry Linear Evaluation Of Bridge Technical Condition

Since the bridge structure is affected by many internal and external factors, andwith the extension of the service period, the structure geometry linear will occur somechanges. At present, the domestic relevant specifications for the geometry linearevaluation index are basically described by qualitative methods, even if somespecifications had a certain quantitative analysis results, but still can not meet thetechnical condition of the existing bridge assessment requirements. By selecting the twomore common beam bridges and arch bridges, using the midas civil finite elementanalysis software to establish a representative analysis model of each bridge, simulatemultiple structural changes in linear situations that may arise and to study the changerule of internal force of bridges after the structure linear have changed, and establish theappropriate analytic hierarchy model, propose by introducing the linear factorparameters to explore the bridges technical condition evaluation methods which basedon the structure linear has changed. The main contents of this article are the followingaspects:①A brief introduction of the significance, importance and research status at homeand abroad of the existing bridges technique condition quantitative evaluation,andbriefly describes the evaluation methods, theories, and some of the shortcomings of theexisting bridges in the technical condition evaluation of the domestic norms.②A brief introduction of three common forms which the bridge structure linearchanges, and from the loss of prestress, concrete shrinkage and creep, design theory,construction to operation of the late management analysis of the various causes ofbridge structure alignment later change.③Describes several models of arch bridge’s main arch deflection, and selects thepolyline deflection form to complete the deflection value distribution on eachsection.uses midas civil software to establish finite element analysis model of archbridge, simulates the different deflection value and deflection length range, each controlsection’s Influence and change rules of internal force of main arch under overalldeflection and local deflection of the arch bridge structures.④Briefly describes two possible deflection modes of the beam bridge structure,focuses on and deduces the formula of the deflection curve mode, and gives thedeflection value calculation method of each section when the maximum deflection value and deflection length range which was known, uses midas civil software to establishfinite element analysis model of beam bridge, simulates thedifferent deflection valueand deflection length range, each control section’s Influences and changes rules ofinternal force of main beam under overall deflection and local deflection of beam bridgestructures.⑤An analysis of the structural linear indicators current situation of the arch andbeam bridge in demestic technical condition of the bridge evaluation system, establishesanalytic hierarchy model of the arch and beam bridges, and analysis the geometryindicators separately, and proposes by introducing the structure geometry linearinfluence factor αgand αlto evaluate method of the technical condition of the bridgewhich based on the sructure alignment index was quantified.