Research on the bridge monitoring method of ground-based radar

Abstract

Bridge is an important infrastructure, and with the increase of bridge construction, the factors such as material aging and traffic congestion will affect the structural health of bridges. Therefore, the special attention should be paid to the regular deformation monitoring and health assessment of bridges. Due to the increasing monitoring requirements for large scale and span bridges, some new monitoring methods should be added as a complement to traditional monitoring methods such as precise leveling, total station, GNSS, terrestrial laser scanning, and so on. With the unique advantages of non-contact and real time, the microwave interferometry technology has become one of the means for deformation monitoring of bridges. The ground-based interferometric radar system has a high sampling rate in both the time and space domain, and it can be an effective complement to traditional methods. In this paper, the basic principle of ground-based interferometric radar system for dynamic deformation monitoring is briefly described. An improved projection method for computing the deflection with ground-based radar data is illustrated and is compared with the traditional projection method. A method for local relative deformation analysis of the bridge based on the characteristics of ground-based radar data is proposed. There are two parameters described for evaluating the local deformation of the bridge. Through the analysis of the deformation process of the bridge in a static load experiment, the feasibility of the method in the actual bridge structure safety monitoring is illustrated.