Research On Videogrammetry For Dynamic Displacement Monitoeing Of High-Rise Buildings

With the rapid development of China economy,a great number of novel style and complex shape high-rise buildings are constantly emerging.It will bring a lot of security issues during the total life cycle including the construction period and operation period.Displacement is a good descriptor of the structural behavior and safety status,and thereby it’s a key monitoring item in both structural construction monitoring and structural health monitoring.Although there are many methods of displacement measurement,but they can not fully meet the needs of dynamic displacement monitoring of high-rise building.Measuring displacement of structures under dynamic excitations is still a challenging task.Videogrammetry shows great potential for dynamic displacement measurement,benefiting from its non-contact and cost-effective characteristics.Nevertheless,its accuracy of long-distance remote videogrammetry and its all-weather performance has to be fully evaluated.For this kind of problems,videogrammetry for dynamic displacement monitoring of high-rise buildings needs to be studied in this paper.The main research contents are as follows:1.According to measurement accuracy test of long-distance videogrammetry,the measured displacement data and virtual displacement data are compared under different measuring distances.The effect of the measuring distance on the measuring accuracy of videogrammetry is analyzed.2.In order to evaluate the work performance and measurement accuracy of videogrammetry system under the adverse environmental impacts,long-term outdoor dynamic displacement monitoring tests using videogrammetry were carried out.According to the dynamic displacement of high-rise building,the data measured under raining conditions were analyzed.It is found that raining imposes significant effect on the videogrammety,and adaptive filtering was proposed to de-noise the displacement measurement data.3.Taking a high-rise residential building in the Wenzhou Zhixin square as the study objective,an industrial digital camera was used to monitor the dynamic displacement characteristics of the building under wind load action.The dynamic displacement time history and the first natural frequency of the building were obtained from the industrial digital camera system.It is also expected that the results presented in this study should be valuable for dynamic displacement monitoring of high-rise buildings.