3651

3450

كارشناسي ارشد

سازه

اصفهان :دانشگاه صنعتي اصفهان ، دانشكده عمران

1386

يازده ، 218،[II]ص.:مصور ،جدول ،نمودار

ص.ع.به فارسي و انگليسي

امير مهدي حلبيان ،حميد هاشم الحسيني

محمد رضا بهبهاني فرد

13/5/86

فياض رحيم زاده ،مجتبي ازهري

مهندسي عمران

ID3450

به فارسي و انگليسي :قابل رويت به صورت نسخه ديجيتال

AbstractLong span cable stayed bridges can inherently undergo to geometric and materialnonlinear behavior when subjected to extreme events Cable s sag P effect in towers andalso large deformations of the deck are major source s of geometric non linearity in suchstructures Considering the ambient loads such as earthquake the bridge deck is usuallysubjected to a considerable axial force due to the horizontal components of cable reactionsand geometrical nonlinearity In such cases part of the deck may enter to local postbuckling In the current research the local post buckling behavior of the bridge deck underseismic loading has been investigated Simulations have been carried out using an explicitdynamic method for a three dimensional finite element model of cable stayed bridge A comprehensive parametric study has been conducted on dynamic characteristics ofbridge By using beam element with low bending stiffness in the simulations some ofbridge s dynamic parameters such as natural frequency and vibration mod shape have beenestimated through selection and the development of cable finite element model In thisstudy based on frequency analysis natural frequency of bridge has been estimated in arange of 1 0 2 Hz Seismic response of bridge to ground motions was investigated forseveral earthquakes in two cases of uniform and non uniform input supports Also thebridge behavior under seismic loads has been studied considering small and largedeformations Results show a considerable difference in seismic response of long spancable stayed bridge in cases of geometric linear and non linear behavior Non linear behavior of deck material was investigated considering uniform and non uniform spatial earthquake under geometrical linear and non linear analysis Results alsoshow that seismic response of bridge considering non linear and linear behavior of deckmaterial had no significant difference Also the effect of bridge deck s main span length onseismic behavior was investigated According to the results increasing of main span lengthdo not necessarily lead to increasing of stresses and forces in bridge components Inaddition a comprehensive parametric study was conducted considering cable pre tensionforce and flexibility of foundation Also parametric seismic studies considering uniformand non uniform ground motions of several earthquakes using linear and non lineargeometrical dynamic analysis were conducted Response of bridge did not increase withincrement in deck negative sag and foundation flexibility and response of bridge isdependent on earthquake record and consisting frequency According to the previousanalysis the local post buckling of bridge deck was studied Results show that in caseuniform ground motions of considered earthquake was investigated considering largedeformation part of deck entered to local post buckling

امير مهدي حلبيان ،حميد هاشم الحسيني

محمد رضا بهبهاني فرد

فياض رحيم زاده ،مجتبي ازهري