The Application Of Finite Element Response Surface Method In The Reliability Analysis Of Earth And Stone Dams

Earth and stone dam adapts to the foundation deformation ability,and has the advantages of economy,safety,convenient material transportation and strong seismic resistance,is a common dam type.However,due to the complex environmental conditions of the dam site of the earth and stone dam,there are many factors from the inside and outside,and the technical parameters of the earth and stone dam and the bearing of seismic load have certain randomness.The structural analysis of its dynamic parameters using constant values often shows limitations.Coupled with more earth and stone dam accidents,and even the occurrence of dam failure and other serious accidents.Therefore,it is necessary to carry out safety and reliability analysis of earth and stone dams.Reliability analysis,a statistical analysis of probability based on data collection,data,and experimental data.In structural design,the method of probability theory is used to consider the uncertainty of various influencing factors of structure quantitatively,and the safety and reliability of structure are measured according to probability theory and statistical theory.Earth and stone dams are dams built by filling and crushing of earth and stone.The distribution,compactness and so on of dam material are random during construction,while their physical and mechanic properties are spatially variable.Therefore,the reliability theory is used to analyze the force,deformation and stability of the earth and stone dam,in order to better grasp the state of the earth and stone dam in the actual work,and evaluate its safety.Because the structure of earth rock dam is complex,it usually involves many random variables.The limit state equation is usually a nonlinear and implicit equation of parameter random variable.Therefore,it is difficult to calculate the reliability index of excavated rock dam accurately.In this paper,the response surface method of structural reliability analysis and static finite element analysis and calculation of earth rock dam are combined.Taking Guanyin core wall earth rock dam as an example,the random finite element static calculation is carried out,and the reliability of earth rock dam is analyzed on this basis.The main research work is as follows:(1)The finite meta-grid model of the earth and stone dam of Guanyin rock core wall is established,and the static stress strain calculation of the earth and stone dam under the design condition is carried out,and the deformation characteristics of the earth and stone dam body are determined.According to the statistical results,it is assumed that the parameters of Duncan Chang E-B model obey the normal distribution approximately,and the reliability of the earth rock dam is analyzed.(2)According to the coefficient of variation of E-B model parameters,K_b and K are selected as random variables,and the other E-B model parameters are constant for dam reliability analysis.The reliability index and failure probability of the maximum settlement point of the dam are solved by using the response surface method and the improved first-order second moment method,and the reliability under different limit states is analyzed.