Finite Element Analysis Of Stability Of Concrete Gravity Dam Based On ANSYS

Gravity dam is one of the most important structures in hydraulic engineering.It has the advantages of simple construction technology,fast construction speed,low requirement for geological conditions,safety and reliability,and is the most widely used dam body in China.The stability and safety of gravity dams are of great practical significance to people’s lives,property and safety in downstream areas.In recent years,with the activities of global seismic plates,earthquakes occur frequently and are very vulnerable to geological disasters such as earthquakes.So far,China has built a large number of small and medium-sized dams,which are widely distributed throughout the country.When earthquakes occur,these small and medium-sized dams are vulnerable to earthquake damage and often suffer from secondary disasters.Therefore,attention should be paid to the seismic characteristics of small and medium-sized dams.It has important significance.A concrete gravity dam is a large-scale controlled water storage project currently being constructed,and it is an important hydraulic structure in this area.In this paper,a three-dimensional integral finite element model of the concrete gravity dam is established by using the large-scale finite element software ANSYS.The stability under static conditions and the seismic stability characteristics of the dam are studied and discussed in depth.The main research contents and results are as follows: Next:1)The finite element method for static and seismic analysis,modal analysis of structures in seismic analysis,response spectrum method and program flow of ANSYS finite element software are introduced,which provide theoretical basis for the numerical calculation and analysis of the paper.2)A three-dimensional integral finite element model of a concrete gravity dam is established by using solid45(bedrock)and SOLID65(dam)elements in ANSYS.The static analysis of the dam under three working conditions,namely,empty reservoir,normal storage level and checked water level,is carried out,and the deformation and stress distribution of the dam under different working conditions are analyzed.The results show that under static load,the stress and strain of the dam body under various working conditions conform to the general law.The maximum displacement of gravity dam occurs at the top of the dam,and the stress on the upstream heel and downstream toe of the dam does not exceed the allowable value of the concrete tensile and compressive strength code.The anti-sliding stability of gravity dam shows that the dam body meets the requirements of anti-sliding stability.3)Based on the APDL language in ANSYS and the command flow compiled by structural dynamics,the modal analysis and response spectrum analysis of the concrete gravity dam are carried out.The working conditions of the empty reservoir and the hydrodynamic pressure applied by the additional mass method are checked respectively.The natural frequencies,natural vibration periods and modal deformation of the structure are calculated,and the modal division is adopted.The response spectrum method is used to analyze the dynamic response of the structure.The calculation results show that after considering the effect of water on the dam body after reservoir impoundment,the dam body mass increases,the natural frequency of the dam body decreases,and the dam body mainly vibrates along the X direction of the river.Only under the action of empty reservoir,the gravity dam will produce serious deformation in the sixth order,and the gravity dam will also occur in the sixth order under checking flood level.Serious distortion,the tensile stress value of dam body under each working condition is larger than the allowable value of concrete tensile strength of 1.2 MPa.Dam body is seriously damaged under earthquake,and some measures are needed to reduce the larger stress concentration.In this paper,the research results of the paper have a certain guiding significance for the design and construction of the project,and have a certain reference value for the monitoring of the later stage of the project from the completion to the impoundment process and the construction of similar projects.