Long-term monitoring and data analysis of GNSS vertical deformation time series of the supporting tower of the Forth Road Bridge
The long-term monitoring of the supporting towers of long-span suspension bridges is of great importance to understand the change of structural behaviour in long time scales and evaluate environmental effects caused by temperature,weather conditions and ground movement.In this paper,the GNSS vertical deformation time series of 33 months from the south tower of the Forth Road Bridge(FRB)in the UK are analysed for the comprehension of its deformation mechanism.Firstly,a new measurement and data strategy is proposed to facilitate the signal extraction of the vertical deformation time series.Then,the fast Maximum Likelihood Estimation(MLE)was adopted with five different combinations of the noise model to identify that the optimized noise characteristics is flicker noise+white noise,and the parameters of the linear and non-linear variation trends are simultaneously estimated with the determined optimal noise model.The linear trend that is mainly caused by the ground movement or permanent deformation is estimated to be-4.33 mm/year,which matches quite well with the InSAR monitoring results of the area surrounding the FRB and demonstrates the stable foundation of the tower.The amplitudes of annual and half-annual signals are estimated to be 9.9 mm and 2.9 mm,respectively.These results are highly consistent with the relevant amplitude results achieved by a classical thermal expansion model and 15 months meteorological data.The consistency can reach 93.9%and 72.4%in the amplitude of the annual and half-annual signal,respectively.Thus,the thermal effect is demonstrated to be the primary factor contributing to the annual and half-annual signals of the vertical deformation time series.On the contrary,the possible imperfection or accumulated damage results in nearly no contribution to the annual and half-annual periodic variations,which reflects the good structural behaviour of the FRB tower at the same time.
GNSS Structure Health Monitoring Vertical Deformation Mechanism Explanation
Qusen Chen Boxiao Ju Xiaolin Meng Weiping Jiang
School of Geodesy and Geomatics,Wuhan University,Wuhan City,China;Nottingham Geospatial Institute/Si School of Geodesy and Geomatics,Wuhan University,Wuhan City,China Nottingham Geospatial Institute/Sino-UK Geospatial Engineering Center,The University of Nottingham,U
国际会议
The 7th World Conference on Structural Control and Monitoring(7WCSCM)(第七届结构控制与监测世界大会)
青岛
英文
3049-3057
2018-07-22（万方平台首次上网日期，不代表论文的发表时间）