列车活载作用下超大连跨悬索桥的刚度特征

Rigidity Characteristics of Multi-span Suspension Bridges under Train Loads

为探索超大连跨悬索桥的可行性,采用重力刚度法研究了超大连跨悬索桥在铁路活载作用下的刚度(坡度变化)特征.根据列车活载的作用位置,将桥梁沿纵向划分为车前、车下和车后3个坡段,分别探讨了它们的最大转角变形.还对不同垂跨比、跨度和连跨悬索桥的跨数进行了参数研究,分折了不同参数对连跨悬索桥刚度的影响.结果表明,车前和车后坡段的坡度变化随垂跨比增大而增大,随跨度增大而减小;车前坡段的坡度变化随悬索桥跨数的增加而减小,车后坡段的坡度变化随悬索桥跨数的增加而增大.

To probe into the feasibility of super-long multi-span suspension bridges,the rotational deformation of super-long multi-span suspension bridges under train loads was researched.The classical gravity stiffness method was employed to derive the influence line of rotational deformation.The stiffening girder was divided into three units in the light of the position of train： front-train unit,under-train unit and rear-train unit.The maximum clockwise and anticlockwise rotational angles were analyzed.Parametric studies were carried out for different sag-to-span ratios,span lengths and span numbers,and their influences on the rotational deformation were evaluated.The research result shows that the rotational deformations of the front-train unit and the rear-train unit increase as sag-to-span ratio raises and span length decreases,and the rotational deformation of the front-train unit decreases with the increase of span number,while the rotational deformation of the rear-train unit raises as span number increases.