GNSS Precise Positioning Technique And Its Applications For Deformation Monitoring Of High-rise Buildings

With the rapid development of China's economy and the acceleration of urbanization,more and more people are pouring into cities.To ease the strain on urban land and adapt to the needs of high-density and cluster-based urban development,high-rise and super-high-rise buildings are also It has mushroomed like bamboo shoots.During the operation of high-rise buildings for several decades or even hundreds of years,due to the effects of long loads,material aging,and component defects,the structure will gradually accumulate damage,so that the bearing capacity of the structure will be reduced,and strong winds and earthquakes will be encountered.When the load is applied,it will cause unpredictable loss of life and property.In addition,the acceleration of urbanization,the exploitation of groundwater and the construction of underground traffic projects will lead to the subsidence of the region's surface,affecting the health and safety of the surrounding high-rise buildings.Therefore,how to monitor and diagnose the health status of highrise buildings in real time,efficiently,accurately,and with high reliability,detect structural damage in time,predict possible disasters,and assess the safety and reliability during service are performed on buildings.Normal operation has very important practical significance.The Global Navigation Satellite System(GNSS),represented by the United States GPS,Glonass of Russia,Galileo of the European Union and Beidou of China,has become the most advanced deformation monitoring method at home and abroad with its advantages of high precision,high speed,and all-weather.one.This paper focuses on the deformation monitoring of high-rise buildings,focusing on the application of GNSS in the field of the best positioning model and its key technical issues such as accuracy and reliability.The main research contents are as follows:1.The application status and existing problems in the field of high-rise building deformation monitoring are discussed.Based on the analysis and comparison of multiple positioning models such as conventional relative positioning and precise single-point positioning,the single epoch algorithm model and its application in deformation monitoring are mainly studied.Advantages and problems.2.The main error sources of GNSS systems and their elimination and attenuation methods are analyzed.In view of the high multipath effects in the high-rise buildingsin urban environments,design experiments are conducted to use the measured data to focus on the characteristics of multipath effects in urban high-rise buildings.Site selection and instrument selection and other key issues.3.Focusing on the GNSS single epoch algorithm,a GNSS single epoch algorithm was designed,a database was designed around the model,a four-parameter coordinate transformation model that facilitates intuitive interpretation of deformation monitoring results,and a multivariate regression model for subsequent deformation trend forecasting were developed to provide GNSS high-rise building deformations.Monitoring system design and implementation program.4.Using the deformation monitoring system designed in this paper,we selected a typical teaching building in our school to develop a variety of experimental programs to verify the accuracy,reliability,timeliness,and availability of the system.