Research On Construction Technology And Mechanical Property Of Suspender Replac-Ement For Mid-Supported Arch Bridge

Due to the technical level of the construction of the medium-sized arch bridge in China and the improper use in the later stage,in recent years,the boom has been damaged due to rust,fatigue and other reasons.The disease of the boom may lead to serious accidents such as the collapse of the bridge and even the bridge,which seriously endangers the personal and property safety of the people.Therefore,it is necessary to study the construction process and mechanical properties of the boom replacement.In this paper,the temperature rise of the temperature rise simulation jack is used to simulate the bridge deck hanging method and the temporary boom lifting process of the arch rib hanging method.The theoretical calculation value and construction monitoring measurement of the bridge deck hanging method are compared with the actual engineering.Value,comparative analysis of the changes of arch rib stress,arch rib displacement,boom cable force and bridge deck deformation under the two boom replacement processes,the following conclusions were drawn:(1)The actual bridge deck stiffness of the hot spring bridge should be significantly larger than the finite element theoretical value,which will cause the cable tension of the boom near the boom to be unloaded at the same time.In the future construction scheme design of similar projects,the influence of bridge stiffness should be fully considered to avoid The insufficient unloading of the cable force to be replaced causes the bridge deck to be damaged or even more serious when the boom cable is cut;(2)During the construction monitoring of this project,only the cable force of the replacement boom and adjacent boom and the elevation of the bridge deck are measured.However,in the research,it is found that the cable forces of the adjacent 6 booms(3 on each side)will have Obvious changes in the law.In order to facilitate research,it is necessary to expand the measurement range in the similar construction monitoring in the future;(3)In view of the bridge deck hanging method,the arch ribs near the arches will be significantly increased,and the cable force of the boom near the boom to be replaced will increase significantly.At the same time,the maximum cable force of the bridge deck crane method is also significantly larger than the maximum cable force before construction.In contrast,the arch rib hanging method has less adverse effects on the structure.Therefore,under the sameconditions,the arch rib hanging method has less influence on the remaining structure.Especially when there are more serious diseases in the vicinity of the boom,and the work cannot be done better,the arch rib hanging method is safer than the bridge deck hanging method.