Analysis Of Spatial Static Characteristics Of Telescopic Structure On Multi-Pylon Cable-Stayed Bridge

With the fast development of the long-span bridge especially the cable-stayed bridge in recent years, the traditional expansion joint can no longer meet the needs of the bridge development due to its own limitations. Therefore, it is essential to find a new expansion structure. Under this circumstance, some experts and scholars have applied the operational mode of piston in mechanics to civil engineering and thus put forth the thought of hinge joint, resulting in the emergence of the rigid hinge. Although the rigid hinge has already been used in the construction of the long-span bridge, the research about it is still at the fundamental stage. This thesis is intended to analyze the contribution of the rigid hinge to the bridge construction as well as its mechanical properties as a component able to withstand the force under the effect of static load.Based on the theory of Finite Element Method and aided by the FEM software such as BSAS, ANSYS etc.the thesis tries to give a holistic analysis of the influence of the rigid hinge on the bridge girder and the cable support tower under the normal operation so as to certify its significant function as a new expansion joint in the bridge construction under the normal operation.Then the thesis has a partial analysis of the rigid hinge on the basis of holistic analysis to assure the stress condition of each rigid hinge component under normal operation and also has an analysis of whether the supports of the small box girder would be detached from and virtually connected with the box girder.From the model analysis of a whole bridge in this thesis, it can be concluded that without regard to the temperature load under the normal operation, the existence of the rigid hinge has little influence on the stress distribution and stress level of the main girder and cable support tower and with regard to the temperature load, the existence of the rigid hinge is able to sustain the distortion of the main girder as a result of the temperature changes so as to make the stress of the main girder and cable support tower as small as possible by the temperature changes. In the study of the parts of the rigid hinge, it is found that under the load effect the small box composed of rigid hinges is able to withstand the external load well and its stress level is in normal function and under the effect of positive and negative flexural moment the some support saddles in the box girder will become virtually connected with the small box girder.In conclusion, the rigid hinge, as a expansion joint, has strong deformation ability and is able to sustain the huge displacement of the long-span bridge caused by the temperature changes so that it eliminates the potential risks resulting from the large stress the structure has to withstand as a result of the temperature changes. Meanwhile, the rigid hinge is also able to bear the effect of external load as a load-carrying structure.