Study On Weight Coefficient In Evaluation Of Technical State Of Double-curved Arch Bridge Based On Damage Effect

The double-curved arch bridges built early in China have caused varying degrees of disease in most bridge structures due to the background of the times and the current design level and low standards of the process.Some of them even have developed into dangerous bridges.Such a large number of double-curved arch bridges,if demolished and rebuilt completely,will not only be economically unacceptable,but also lead to waste of resources,pollution and destruction of the environment.Therefore,the targeted repair and reinforcement of the old double-curvature arch bridge is the way to solve the above problems,and the premise of maintenance and reinforcement is to be able to accurately assess the degree of damage of the bridge structure.Then,the science of the existing double-curved arch bridge The assessment of effective technology status is particularly important.When assessing the technical status of a double-curvature arch bridge,the Evaluation Standards for Technical Conditions of Highway Bridges(JTG/T H21-2011)are divided into three parts: the main arch ring,the arched structure,and the deck slab.Because the main arch circle consists of four parts: arch rib,arch wave,arch plate and horizontal beam.If the main arch ring is used as a component,the overall assessment is a little rough,and it can not reflect the damage of the components of the main arch circle.This is the starting point for studying the weights of the components of the main arch of a double curved arch bridge.The damage of the bridge structure will lead to the reduction of the structural rigidity.Taking the double-curved arch bridge of the Baoku River in Xining City of Qinghai Province as the research background,the finite element model of the bridge was established using the finite element software ANSYS.The degree of damage was simulated with the stiffness change,and the main analysis was performed.When the stiffness of each component of the arch ring(arch rib,arch wave,arch plate,and horizontal beam)changes,the stress and deflection of the control section and the change law of the structure's natural vibration frequency are used to determine each component in the main arch circle.Based on the degree of importance,and based on this,the two-to-two judgment matrix of each component of the main arch circle was established,and the weight values of arch ribs,arch waves,arch plates,and horizontal beam were calculated using the analytic hierarchy process.With reference to the assessment methods and standards for the “Technical Assessment Standards for Highway Bridges”,the technical status of the arch ribs,arched waves,arched plates,and horizontal trusses are evaluated,and the technical status score of the main arch circle is calculated by taking into consideration their respective weight values.Compared with the evaluation result of the standard [8],it is slightly larger,and this deviation is within the interpretable range.It is proved that the scientific rationality of the weight values of the components of the main arch circle can be used for the reference of the same bridge structure as a bridge.The conservation,maintenance,transformation,and reinforcement provide decision-making opinions.