| As an important force transmission device of the bridge system,the bearing is an important component connecting the superstructure and the substructure of the bridge,which has the function of reliably transmitting the action force of the superstructure of the bridge to the lower structure of the bridge.For ultra-wide single cable-stayed bridges,the partial loading of the lanes,the emptying of the bearings and the arrangement of the bearings will all have a certain influence on the mechanical performance of the structure.Therefore,it is necessary to study the degree of influence of the partial load of the lane,the emptying of the bearings,and the arrangement of the bearings on the bearing performance of the cable-stayed bridge,so as to provide basis for the design,construction and later operation.This article takes the Beijiang Fourth Bridge of Qingyuan City in Guangdong Province as an engineering example and specific research results are as follows:1.The influence of the partial load on the mid-span cross-midspan deflection and the horizontal displacement at the top of the tower is very small,and the full-bridge full load maximizes the mid-span cross-midspan deflection and the horizontal displacement at the top of the tower.The phenomenon of stress redistribution under partial load is not obvious,but the stress concentration near the bearing is quite prominent.2.Under the condition of a single seat being emptied,the phenomenon of redistribution of counter-reaction force is prominent.The counter-force at the place near the vacant place of the pedestal has increased significantly.The effect of the detachment of the mid-span side pedestal on the counter-force is greater than that at the side-span.The impact of the emptying of the side support on the counter force is greater than that of the middle bearing.When the double bearings are removed,the support branch reaction force has exceeded the safe tolerance range,which will lead to the destruction of the support.3.The removal of the mid-span side bearings from the single bearing seat has obvious influence on the stress redistribution of the zero block,the mid-span mid-span deflection,the horizontal displacement of the tower top,and the internal force of the mid-span steel box girder bending moment,while the side span The impact of the above-mentioned factors on the clearance of the side bearings is relatively small.The maximum and minimum bending moment values of the mid-span steel box girder under the double bearings have significant changes;the mid-span mid-span deflection and the horizontal displacement at the top of the tower increase significantly,making the deformation of the bridge structure too large;the stress concentration phenomenon of the zero block prominent,easy The local damage caused by the zero block seriously affects the performance of the bridge structure.4.Fix the position of the main pier’s side support and change the distance of the middle support from the center line to study the influence of the arrangement of the support on the force of the support.Through the study,it was found that when the position of the side bearing is fixed,the force of the bearing is more reasonable when the middle bearing is 200 cm away from the center line.5.The vertical deflection in the middle span and the horizontal displacement at the top of the tower increase with the increase of the bearing spacing,and the increase is gentle.6.When the position of the side support is unchanged,the distance between the middle bearing and the center line of the bridge is 200 cm,which is the optimal distance.After more than 200 cm,with the increase of the spacing,the stress of the zero block increases.The increase curve rises smoothly;in the case where the spacing is less than 200 cm,the stress of the entire zero block also decreases as the spacing decreases,and the curve decreases smoothly,but the stress concentration near the bearing is serious,and the overall stress performance of the zero block results.negative effect. |
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