Static Analysis Of Earth Rock Dam Considering Spatial Variability Of Material Parameters

With the continuous development of our country’s water conservancy and hydropower industry,the number and height of earth-rock dams in our country have increased significantly.However,most of these dams are located in the southwest region where the earthquake is relatively strong,and if they crash,they will cause incalculable losses.Therefore,the safety of earth-rock dams is particularly important.Dam deformation is one of the core issues in the safety evaluation of earth-rock dams.At present,the finite element method is the main means for deformation calculation and safety evaluation of earth-rock dam.The traditional finite element method is usually used to calculate and analyze the mechanical parameters of uniform soil and stone determined by laboratory tests.However,from the actual situation of field construction,there are differences in the lithology,weathering degree and filling quality of soil and rock materials in the same dam material partition,which leads to the differences in the values of material mechanical parameters in the same dam material partition.So these indicates that the mechanical parameters of the dam body have certain spatial variability.In addition,the field survey results show that there is a more obvious overhead phenomenon in the weir dam formed by the landslide caused by the earthquake,and the indexes such as soil particle gradation and dry density are highly discrete.It can be seen that the internal mechanical parameters of materials have the characteristics of spatial variability,whether it is artificial filled dams or weir dams formed by earthquakes.The spatial variability of mechanical parameters can not be considered in the traditional finite element analysis,which makes the calculation results and observation results have some differences.Therefore,the random field finite element model of earth-rock dam material parameters is established by using the spatial random field theory,and the random finite element analysis of earth-rock dam is carried out to obtain the material parameters of earth-rock dam.In this paper,the random finite element static analysis of the spatial variability of material mechanical parameters for the earth-rock dam on the right bank of the Guanyinyan hydropower station and the Hongshiyan dam is carried out.The main research contents are as follows:1.Use the covariance matrix decomposition method to construct a two-dimensional random field model of the Guanyinyan rock-earth dam,and study the influence of the mesh model size on the random finite element calculation results of the earth-rock dam;2.Study the influence of different random field sample size on the calculation results of earth rock dam,and determine the appropriate random field calculation times;3.The covariance matrix decomposition method is used to construct the three-dimensional random field model of ruby rock dam,and the statistical characteristics of correlation distance and mechanical parameters are determined;4.Carry out two-dimensional and three-dimensional random field static analysis on Guanyin rock earth-rock dam and Hongshiyan dam respectively to determine the statistical law of dam settlement of the two dams.