Behavior Of The Tied-arch Railway Bridge With Different Hanger Arrangements

The research question of this thesis originates from a variant study for a tender design to determine the optimal hanger arrangement for a railway arch bridge.This railway arch bridge is the real project of 1-128 m Urumqi Large Bridge of Lanxin Railway.The purpose of this master thesis is comprehensive comparison the stress-strain state of the tied-arch railway bridge.In the variant study for the tender design,three different hanger arrangements were investigated: vertical,inclined with constant slope by P.Tveit theory and inclined variable slope by B.Brunn and F.Schanak theory.The structure of the study: geometrically non-linear calculation of different load combinations.Check hangers for the effort;Verification of cross-sections tightening and arches for strength,selection of reinforcement tightening,optimization of structures;Approximation of geometrically nonlinear structures of linear schemes for the construction of lines and surfaces influence;Modal analysis.Study of structures carried out on the spatial analysis models in the software package LIRA-SAPR version 2017.This software package allows to take into account physical,geometrical,structural nonlinearity,load model to build the lines and surfaces influence efforts and movements in all finite elements,calculations of strength and stability.According to the results of static and dynamic analysis of three systems of tie-arches,performed in this work.System with vertical suspensions on the perception of temporary loads mainly works due to the stiffness torque,bending and axial,and a system with sloping suspensions – by self-tension,reducing thrust and moments in the tie.Due to self-tension system with sloping hangers are much less susceptible to uneven load cases(S-shape deflection)than a system with vertical hangers.Among the systems with sloped hangers effect the selftension under its own weight in the best way expressed in the system B.Brunn and F.Schanack theory.The modal analysis of the three systems also shows that the system with vertical suspensions has the lowest rigidity in the vertical plane under the influence of temporary loads,and the system with the highest one is the B.Brunn and F.Schanack system.In general,tied-arch systems with inclined suspensions are the most suitable for railway loads(both conventional passenger-freight and high-speed),and the more acute the angle of incidence of suspensions on the tightening,the greater the system's resistance to uneven loads and the dynamic effects of rolling stock.