Analyses of finite element model based on station’s tectonic environment: Taking Qianjiang station for example

The site environment is the most direct factor affecting the observation data. In order to better apply the deformation observation data and find out the related physical meaning, this paper built a finite element model based on the deformation data from Qianjiang station, and further analyzed the observation data based on the working principle of the instrument. The tectonic environment of Qianjiang station is complex, a large number of northeast-trending faults and folds were developed due to the long time pressure in northwest direction, which has a certain influence on the observation data. The data analysis results based on the finite element model show that the Silurian shale appears as an uplift bending deformation and forms an anticline under the pressure, the whole rock layer is inclined to the southeast direction, the vertical deformation of the overlying rock is greater than the horizontal deformation, and the tendency of fault and fold-axis has influences on the transmission of stress. According to the long-term observation data from Qianjiang station, the results of the model can reasonably explain the mechanism of the expansion of the telescopic instrument under the structural background of the pressure. Furthermore, the model results are consistent with the long-term trend of the vertical pendulum, which is more in line with the physical meaning of the actual observation, that is, the finite element analysis of the site structure environment will help us to better understand and apply the deformation observation data, and thus explore the actual physical meaning of the observed data.