Existing bridge availability evaluation method in highway reconstruction and extension project

Abstract

The invention discloses a method for evaluating availability of existing bridges in a highway reconstruction and extension project, which comprises the following steps of: 1, evaluating technical conditions and bearing capacity of the existing bridges in the highway reconstruction and extension project, and for the bridges of which the technical condition grades are evaluated as 3 classes, 4 classes and 5 classes and the bridges of which the technical condition grades are evaluated as 1 classes and 2 classes but the bearing capacity does not meet requirements, judging whether the technical condition grades are 3 classes, 4 classes and 5 classes; the method is not suggested to be continuously used in reconstruction and extension projects; and step 2, for the bridges which are evaluated as the class 1 and the class 2 and of which the bearing capacities meet the requirements, dividing main body structure component classes, calculating the score of the appearance durability state of any main body structure component class, and if the score reaches a threshold value range, not suggesting to be continuously used in the reconstruction and extension project. According to the method, qualitative and quantitative combination is provided for the durability of the bridge, the current safety state and the future durability condition of the bridge are fully considered, more sufficient safety guarantee is provided for reuse of the bridge in the reconstruction and extension project, and the long-term safety performance of the bridge in later operation is guaranteed.

Description

technical field [0001] The invention relates to the technical field of life extension of bridge structures. More specifically, the present invention relates to a method for evaluating the availability of existing bridges in expressway reconstruction and expansion projects. Background technique [0002] With the rapid development of society and economy along the line, the traffic volume of expressways has increased rapidly. Some of the road sections in the early stage of construction in China have reached or are close to saturation, and the service level has seriously declined. The current traffic conditions cannot adapt to its important road network status and future traffic demand. Development requirements, urgent need for reconstruction and expansion. Bridges are the key nodes of the transportation network. Existing bridges have been in service for many years in expressway reconstruction and expansion projects. After years of overload operation, the structural performance...

AI Technical Summary

Problems solved by technology

Although some old bridges seem to be in good overall technical condition, there may be certain safety hazards in some parts or they are basically close to the endurable limit state

In some reconstruction and expansion projects, in order to ensure the coordination of the service performance of the bridge structure system, all the old bridges in the line were dismantled and rebuilt uniformly. The sustainable use value of the old bridges has not been brought into play, resulting in a major waste of resources, which is not in line with the concept of green development

Many existing bridges can achieve the same service life as new bridges through some life extension measures, but there is a lack of a reasonable evaluation method

In some reconstruction and expansion projects, existing bridges with good apparent conditions are directly used, and the bridge can be judged to continue to be used only based on the apparent technical conditions and bearing capacity of the bridge at that time, but the internal deterioration of structural materials is not included. In the later period, it was found that the deterioration process of the bridge was rapid. For example, the protective layer was too thin, resulting in large-scale corrosion after carbonization to the surface of the steel bar, and the maintenance cost was greatly increased. In this case, demolition and reconstruction are more economical than direct utilization

Images