The Study On Safety Evaluation Of Main Dam Operation Period Of Tuokou Hydropower Station

Due to the complexity of the working conditions of the dam and bedrock,and the natural aging of the hydraulic materials,it is impossible for the hydraulic structure to maintain the performance determined in the design stage for a long time,and the dam structure will continue to present safety hazards.Therefore,the safety monitoring feedback of the dam and the timely evaluation of the dam monitoring data are necessary.In this paper,the research is carried out with the Tuokou Hydropower Station running for four years as the engineering background.The specific research contents and main results are as follows:(1)Construct a three-dimensional model of the main dam of the Tuokou Hydropower Station.Based on the design,construction and monitoring data of hydraulic structures,the three-dimensional visualization model of the main dam of the Tuokou Hydropower Station was established by using ANSYS finite element software.(2)Based on the monitoring data of the operation period,the engineering safety evaluation is carried out.According to the series of deformation and seepage monitoring data of each dam section of the main dam,the displacement analysis of the dam body and the dam foundation is carried out to evaluate the relationship between different dam sections and the changes of the ambient temperature and reservoir water level,and the analysis of the uplift pressure,the osmotic pressure and the total seepage flow.The law of variation is used to evaluate the seepage stability and anti-seepage drainage effects of each dam section.Based on the monitoring data of the operation period,the mechanical parameters of the dam such as elastic modulus E,Poisson’s ratio μ and bulk density y are determined by inversion.(3)Evaluation of dam safety based on numerical analysis of multiple operating conditions.Using the inversion parameters,the ANSYS finite element software and FLAC 3D software were used to calculate the deformation and stress variation of the concrete dam section and the clay core dam,and the maximum deformation and maximum stress parts under different working conditions were selected for deformation and stress correction.Nuclear,evaluate the safety of the dam,predict the trend,and initially formulate the deformation monitoring and early warning indicators.(4)Numerical analysis of seepage in multiple working conditions to evaluate the seepage characteristics of the dam.For the concrete dam section,the rockfill dam section and the composite dam joint dam section,the seepage calculation is carried out separately,and the variation law of the osmotic slope and free surface is analyzed,the weaker anti-seepage control effect is determined,and the seepage stability of the dam is evaluated.According to the safety evaluation of the composite dam such as the main dam of the Tuokou Hydropower Station,the connection mode and geometry change of the inserted concrete thorn wall can also be discussed.The dam safety monitoring and early warning indicators are worthy of further study.