Settlement Monitoring and Analysis of High Filling Project for Resettlement Area of Baihetan Hydropower Station

Abstract:

In order to ensure the stability and the serviceability of high filling foundations， the field monitoring of the high filling project of Baihetan Hydropower Station is introduced， and the settlements of the original foundation and the filling are analyzed in this paper. The influencing factors such as the height of filling， compaction degree， time， and variation of groundwater on the settlement are discussed. The results indicate that the settlement of the high filling project with gravel filler is caused by the original foundation and the compression of the filling. The settlements of the original foundation and the filling account for 39.7% and 60.3% of the total settlement， respectively. The proper increase of foundation compaction degree is an effective measure to control the foundation settlement. Different fitting models are used to predict the settlement of high fill foundations， and it is found that the exponential model can successfully predict the settlement of the high filling project. The impoundment in the reservoir causes the groundwater level in the filling area to rise， and the instantaneous wetting deformation of the soil accounts for 60.9% of the total wetting deformation. The increase and dissipation of pore water pressure are mainly affected by groundwater level and filling load. A linear relationship between the magnitude of excess pore water pressure and the filling load is observed and the coefficient is 0.021， indicating that the soil is stable. The excess pore water pressure gradually dissipated after completion.

Key words:high filling project;settlement monitoring;settlement prediction;wetting deformation;pore water pressure