Rail Cable-stayed Bridge Lateral Rigidity Analysis And Study

Now cable-stayed bridge is widely used in rail transit field, rail cable-stayed bridge has a big main span, and its main girder is narrower than normal bridge. The middle of middle span always be the weak point of lateral rigidity, so studying the lateral rigidity of this bridge is necessary.This paper point out some meaningful conclusion through the analysis of assistant pier`s setting, stay cable`s diameter, main tower`s model, main girder`s material, girder form`s mixing.?Placing 1 or 2 assistant pier beside the side span can improve the rigidity at middle of main span in cross-bridge direction.?Increasing the diameter of pier can improve the lateral rigidity of main span`smiddle span appropriately, but The effect is not obvious. Overall, no matter planar or spatial stay cable have little effect on the rigidity at middle of main span in cross-bridge direction.? For cable-stayed bridge with “H” bridge tower of half floating system, increasing the rigidity of bridge tower have little effect on improving he rigidity at middle of main span in cross-bridge direction.?In general, under the condition of the same girder section`s external overall dimension, compared with steel box girder and hybrid girder(steel girder for main span, concrete deck in side span), the lateral rigidity of concrete cable-stayed bridge at middle span is bigger, hybrid girder(steel girder for main span, concrete deck in side span) is second, and steel box girder is the minimum.?For cable-stayed bridge with steel girder for main span, concrete deck in side span, the longer concrete deck in side span into the middle span, the larger lateral rigidity at middle girder of main span, and smaller the contrary.?Changing the width of main girder has great effect on lateral rigidity at middle girder of main span, the larger width, the larger lateral rigidity at middle span, and smaller the contrary.This paper takes Chongqing Gaojia garden railway cable-stayed bridge as the engineering background, combined with the conclusion of the fourth chapter analysis, The improvement measures are put forward for the Insufficient lateral rigidity at middle girder of main span during the preliminary design of bridge: increase the main span`s variable cross-section width at the junction between tower and beam to 14.14 m, horizontal deflection to span ratio at middle girder of main span Just to meet the requirements of specification.Through the influence degree analysis of lateral oscillation force, horizontal wind force, temperature force on horizontal displacement at cable-stayed bridge`s middle girder of main span, Influence of the temperature stress of the tower can be not considered for the calculation of horizontal displacement at cable-stayed bridge`s middle girder of main span in In the analysis of actual simulation. The work in this paper provide some reference of lateral rigidity control design of the same type bridge.