Safety And Stability Analysis Of Gravity Dams Under The Action Of Backwater Backflow

Gravity dams as an important structure of water conservancy projects,play an important function of water storage,power generation,flood control,etc.At the same time,gravity dams can regulate the distribution of water resources,to ensure the needs of various fields such as agriculture,industry,urban water,improve the ecological environment and people’s lives,and are closely related to national development and people’s happiness.Once a dam failure occurs,it will directly threaten the lives and property of the surrounding areas,and the importance of the stability of the dam structure is self-evident.Therefore,this thesis is based on the actual project,the use of finite element method of static and dynamic analysis of the gravity dam by backwater backflow,the study of its hydrostatic characteristics,for the future gravity dam by backwater backflow and the role of earthquake structural analysis to provide research basis,has a certain reference value and guidance significance.In this thesis,a three-dimensional modeling and finite element analysis of a gravity dam based on ANSYS software was conducted to study its static and dynamic properties under backwater backflow and earthquake effects.Under static loading,the analysis shows that the dam exhibits local tensile stress concentrations mainly at the heel and dam site,etc.;meanwhile,large deformations and strong dynamic amplification effects occur near the top of the dam,so that the top of the dam is more prone to sudden changes and horizontal cracks.Under seismic action,the dam model is excited by artificially introduced seismic waves,and the results show that the horizontal seismic action causes distortion,oscillation and larger deformation inside the dam body,especially on the top of the dam,which increases the risk of damage to the dam structure.By analyzing the deformation,it can be determined that the larger deformation,stress concentration and vulnerable parts of the dam must also pay special attention to the effect of horizontal seismic action on its stability.In addition,this thesis also addresses the problem of less research on the safety and stability analysis of gravity dams under the effect of backwater backflow,and conducts hydrostatic analysis for each of the three operating conditions at different downstream water levels to investigate the effect of backwater backflow on the structural stability and safety of the dam.The calculation results show that the deformation and stress values of the dam decrease as the downstream water level of the gravity dam increases,which is beneficial to the safety and stability of the dam structure.Finally,this thesis also considers the effect of seismic action on the gravity dam,and analyzes the deformation and stress of the gravity dam under different operating conditions under the action of backwater backflow.The results show that the local stress concentration phenomenon occurs at the heel of the gravity dam,and the maximum amplitude of the dam usually occurs near the crest of the dam,with a strong dynamic amplification effect.Therefore,a variety of reinforcement measures are needed to solve these problems and effectively improve the structural stability of the gravity dam to ensure its normal operation.