Study of Reasonable Layout of Upper Reinforced Double-Deck Steel Truss Bridge
This study investigates the reasonable arrangement of the upper chords added to enhance the overall rigidity and strength of the steel truss bridge.The Weihe River Bridge carrying a section of the Xi'an Metro Line 10,which is a double-deck steel truss bridge with upper stiffening arches,is used as a case.The parameters numerically analyzed included the alignment of the stiffening arches,height-to-span ratio,span ratio and internal inclination angles,based on the values and uniformity of the efficiency coefficients of flexural stress,design suggestions were given,and the design parameters were optimized by a response surface method.It is shown that the stiffening chord in the hogging moment zone of the concave stiffening chord reveals the best stiffening effect,and internal forces of the long vertical rods are ten times those of the short vertical struts,which was a key design consideration.The height-to-span ratio is directly proportional to the load bearing capacity of the stiffening chord.The influence of span ratio on the load bearing capacity of the stiffening chords showed sign of from decrease to increase,but the influence of the height-to-span ratio is more significant,and exerts weaker influence on the load bearing capacity of the vertical rods.It is suggested that the height-to-span ratio be adjusted before the installation of the stiffening chords.The inclination angles of the stiffening arches exert minor influence on the load bearing capacity of the main trusses.After optimization of multiple parameters,the midspan deflection was reduced by 14.9％.The maximum efficiency coefficient of the main trusses and the average efficiency coefficient of the upper stiffening chords in the negative bending moment zone are reduced by 14.3％and 13.3％,respectively,indicating that the modification of overall arrangement led to the improved structural performance.
double-deck steel truss bridgestiffening chordalignmentdepth-to-span ratioinclination angleefficiency coefficientfinite element method
万方数据
维普
