Research On Cable Replacement Technology Of Special Shaped Cable-stayed Bridge With Universal Hinge Support At Tower Bottom

With the rapid development of China’s national economy and transportation,the special-shaped cable-stayed bridge has developed rapidly.For the cable-stayed bridge,the cable can be regarded as its "life" cable.After the cable is damaged,the bearing capacity of the cable-stayed bridge will decline.However,the corrosion damage of the cable can only be delayed,but can not be eliminated.The serious corrosion of stay cables directly threatens the safe operation of the bridge,but considering the economic cost constraints,the current effective solution is to replace the bridge cables.In recent years,although the cable replacement technology of cable-stayed bridge is gradually mature at home and abroad,the cable replacement of special-shaped cable-stayed bridge has just begun to develop.The bridge that this paper relies on is the first special-shaped cable-stayed bridge with single inclined tower supported by universal hinge at the bottom of tower at home and abroad.Its structural characteristics are quite different from those of conventional cable-stayed bridge.The existence of asymmetric layout of universal hinge support and cables makes it very difficult to control the tower posture and girder line shape of this type of bridge.However,there is no reference for this type of bridge.Therefore,it is of great theoretical significance and engineering application value to carry out the research on the cable replacement technology of single inclined tower special-shaped cable-stayed bridge with universal hinge support.Based on the engineering background of Haitangwan pedestrian landscape cable-stayed bridge in Sanya,this paper studies the cable force,bridge deck alignment and tower posture in the process of cable replacement from different cable replacement sequence and quantity.The main research contents and conclusions are as follows: firstly,the cable force optimization theory of minimum bending strain energy method suitable for this bridge is proposed.Secondly,based on the cable replacement analysis theory,combined with the finite element software MIDAS / civil,the finite element solid model of the whole bridge is established,and the numerical model is verified by monitoring data.On this basis,three different cable replacement methods are proposed,which are disorderly replacement by one,orderly replacement by one and orderly replacement by two The change of the main stress index of the structure under the cable replacement condition of each scheme.Finally,five schemes of orderly replacing cables are compared and analyzed.The results show that:when the cables are replaced disorderly,the removal of any one cable will not cause irreversible damage to the structure;when the cables are replaced orderly,whether they are replaced from inside to outside or from outside to inside has little influence on the final bridge condition;in the orderly replacement scheme,replacing two cables at the same time is the most suitable for the bridge;the adjustment of the front anchor cable to the tower posture before the cable replacement has great influence on the cable replacement The completion of the project played a key role.The purpose of this paper is to study the cable replacement scheme of single inclined tower special-shaped cable-stayed bridge with universal hinge bearing at the bottom of the tower.The research results can provide important theoretical support for the management and maintenance of the bridge in the operation stage.It can also provide important reference value for the selection,design,construction and maintenance of the special-shaped cable-stayed bridge with universal hinge bearing in the future.It will also provide reference for the healthy development of the whole life cycle of the special-shaped cable-stayed bridge For important experience.