Ground-Based Radar Application In Bridge Micro-Deformation Monitoring

Ground-based radar (GB-radar) is a new field of the building deformation observation monitoring equipment, it uses microwave signal to monitoring non-contact scanning measurement, unlike conventional total station, Level, GPS, etc. single-point measurement, the one planar scanning unit with high spatial resolution and monitoring accuracy, the stepped frequency continuous wave technique and interference technique are combined to form a ground microwave radar interference system, access to high-precision, high resolution deformation information, to achieve high precision static and dynamic ground targets monitored. In this paper, the ground-based radar equipment IBIS-S (Image by Interference Survey, IBIS) system is the result of the company by the IDS and the University of Florence in Italy for six years research and development cooperation instruments, able to target to provide continuous and comprehensive monitoring. IBIS-S is mainly used for small changes of objects prone bridges, buildings, towers, etc. accurate monitoring, changes in the measured amount of displacement can be obtained for each portion of the object, each point of the deformation of the analysis on a building or bridge, vibration. For the system in the field of micro-bridge deformation monitoring, the main research contents and conclusions are as follows:(1) Firstly, the hardware and software IBIS-S system equipment composed of equipment, technical parameters and working principle are introduced; a more detailed description of the IBIS-S basic principles of measurement.(2) Study to verify the IBIS-S measurement accuracy through experiments on IBIS-S system with conventional devices compared in simulation and comparison calipers and total station deformation experiments verify its static measurement accuracy of better than 0.1mm.(3) Focuses on the error IBIS-S in the presence of measurement, instrument placement, data conversion and computing environmental factors influence the measurement results. Moving through the tiny instrument around, draw their greatly influenced in the measurement instrument must be placed precisely on the measuring target radial direction. In different environments experimental error of the measurement results influenced by the environment, and found two methods to eliminate the environmental impact of IBIS-S factors:correct formula method and the reference datum correction method, eliminating most of the environmental impacts. Measuring the distance to the object of IBIS-S static measurement results have a significant impact, experiments confirmed within 80m, measurement accuracy better than±0.1mm; within 200m range, measurement accuracy better than±0.23mm; within 300m range, measurement accuracy better than±0.40mm.(4) Based on the characteristics of IBIS-S measurement data for only a single measurement target deformation improve the design of the multiple phase data connection methods to achieve the observed data in different periods can be connected to achieve long-term goals deformation monitoring purposes. By viaduct project example, a detailed description of the principle of the method and implementation steps. IBIS instrument to measure the long-term deformation to be fixed erection long position does not move, and the realization of the connection IBIS more measurement data can overcome this disadvantage and improve the utilization of the instrument. IBIS deformation measurement accuracy± 0.1mm fully meet the requirements of the bridge deformation monitoring.