Research On Carrying Capacity And Assessment Method Of Damaged Double-curved Arch Bridge

Since the birth of Double-curved Arch Bridge, with its beautiful appearance, novel structure, lighter, convenient construction, material saving, etc., have been extensively built all over the country. However, due to various reasons, most of the Double-curved Arch Bridges appear to have different degrees of damage after being put into use for a period of time, it is urgently needed carries on the supporting capacity, can thus carry on the maintenance to service and to reinforce the transformation. Therefore, it is significant to make assessment to the carrying capacity of damaged Double-curved Arch Bridge to ensure the safe operation of the bridge.The key contents in the process of checking the carrying capacity of Double-curved Arch Bridge are to analyze the influence of the joint action of main arch and spandrel structure, filling stiffness, column rigidity, edge abdomen arch support mode, spandrel arch ring stiffness and the damaged structure (main arch ring damaged and upper structure damaged) on the main arch stress. Based on the analysis of the structure calculation and carrying capability of the Double-curved Arch Bridge studied in last ten years, combined with existing results of conventional Double-curved arch bridge finite element model, consider the Double-curved arch bridge damage, by adjusting the cell characteristics to modify the Finite element models, this paper makes an in-depth study using the Finite element method and suggests the corresponding checking method and Finite element models considering certain distress of the Double-curved Arch Bridge. On studying of assessment methods of the Double-curved Arch Bridge, According to the deficiency of previous assessment methods and reliability theory, based on Finite Element, Artificial Neural Networks(ANNs), Response surface method and Monte-Carlo, a new method based on Artificial Neural Networks-Response surface-Monte Carlo (A-R-M) method was investigated. This approach makes full use of the merit of ANNs, Response surface and Monte-Carlo, provides a fresh assessment method of the Double-curved Arch Bridge. The results show that:when live load on the Double-curved Arch Bridge, the joint action of main arch and spandrel structure to the bending moment, the shearing force and the deflection of main arch ring discount is big, while it is not obvious to the axle strength discount. Filler stiffness has greater impact on the forces of the main arch ring. With the filler stiffness decreases, the live load bending moment, stress and deflection of the main arch tended to increase, that is, the smaller the filler stiffness, the more disadvantageous the main arch ring stress situation is, and the joint action of main arch and spandrel structure are less obvious. The abdomen arches has increased the structure overall rigidity, so that the joint action of main arch and spandrel structure was strengthened. The influence of column and ventral arch stiffness on the main arch is great; with ideal hinge simulation in horizontal wall cracks at the end of the circumstance, basically has not slackened the joint action of main arch and spandrel structure. After arch foot and arch crown of the main arch ring partial scope were damaged, the main arch ring overall rigidity has reduces, and the deflection of main arch increases. The arch foot damage or the arch crown damage of the main arch ring, have the obvious adverse effect to the arch foot internal force, but arch foot damage will not have further adverse effect to the arch crown internal force.