Study On Suspender Cable Forces Of A Tied-arch Bridge By Considering Construction Errors

The tied-arch bridge with lots of characteristics such as strong crossover capability, light overall weight, economic and beautiful outlook is widely used in engineering. Usually, the tied-arch bridge is composed of three components of arch, main girder and boom. As the transmission member connecting girders and arch ribs, the change of suspender cable forces directly affects the structural internal force distribution. Therefore, it is vital to determine the reasonable suspender forces. Taking the Nanchang Jiulong Avenue Overpass Bridge (NJAOB) as engineering background, this thesis investigates the suspender forces at reasonable status of the completed bridge and the construction stage by considering construction errors. The main work and conclusions are as follows:1. The development history and current research status of the tied-arch bridge are reviewed. The structure and stress characteristics are briefly discussed. The concept of the reasonable finished state and the reasonable construction state of the tied-arch bridge are introduced.2. The feasibility for using the rigid supported continuous beam as the reasonable finished state of the tied-arch bridge is analyzed. Combining with the method of influence matrix, the method to determine the reasonable finished suspender cable forces of the tied-arch bridge by the displacements of main girder control sections as the objective function is proposed.3. The formal analysis of the various stages of construction simulation is completed. In order to make the simulation calculation model to simulate the actual construction better, combining with the method of influence matrix, the method to determine the reasonable construction suspender cable forces of the tied-arch bridge by the suspender cable forces in different stages as the objective function is presented by considering certain construction error.4. The proposed method which is used to determine the reasonable finished state and the reasonable construction state of the tied-arch bridge is simple and convenient. The consideration of the construction error makes the theoretical calculation more closer to the construction site actual situation. The method has been used for the construction of cable force adjustment in the NJAOB. The results show that this method is practical and reliable, which has certain directive significance to suspender tension construction for a tied-arch bridge.