Analyses Of Operational Stage Performance And Ultimate Bearing Capacity For Steel Struss Arch Bridge

First of all, the development of arch bridge and steel truss arch bridge at home and abroad is reviewed. And the structural characteristics of steel truss arch bridge are summarized. To a 230m span urban steel trussed arch bridge, the project survey and main parameters in bridge design are introduced in detail. A finite element software MIDAS/CIVIL is used to establish a full-bridge analysis model based on beam element to the 230m span urban steel trussed arch bridge, the suspender cable is simulated by truss elements, the other members are simulated by beam elements, the orthotropic steel deck is simulated by beam grillage model. The internal forces, stresses and deformations of truss arch and main girder under the actions of dead load and other 6 load combinations are calculated in the stage of bridge operation. The general finite element software ANSYS is used to establish a detailed full-bridge intergrated element model based on beam elements, truss elements, plate and solid elements. And the detailed stresses of the connection between cable and girder at the binding region of arch and girder are analysed under the actions of dead load and dead load plus vehicle load. An optimizated trial calculation of the number of the webs at variations of the girder is carried on the ANSYS model. And the detailed stresses of the main members at this area are compared and analysed before and after the optimization. Finally, an elastic-perfectly plastic material model is used for steel, and a layered beam element and layer by layer yield model is used for failing adversely section. Ultimate capacity calculation and analysis are done by increasing the load multiple of both the dead load and unfavorable live load and increasing the unfavorable live load only. The corresponding ultimate load factor is obtained at the same time.