Analysis Of Slope Stability Based On Nonlocal Viscous Elastic Plastic Model Under The Dynamic Load

Nonlocal theory is an important part of the generalized continuum mechanics, It is contains some concepts,but the classical theory has not been put forward.Nonlocal theory gave up several assumptions of the classical continuum theory,In a macroscopic phenomenological theory considering the scale effects and the long-range interaction of the microstructures, thus, many problems that are difficult to be explained by classical continuum theory can be investigated effectively by the nonlocal continuum mechanics. These problems include the strain localization, crack tip stress singularity and wave dispersion etc. The nonlocal continuum mechanics provides a new and valuable approach to solve the macro-micro correlation problems in mechanics.Under the framework of nonlocal continuum mechanics, The main objective of this thesis is to investigate some controvertible and unsolved problems existing in the nonlocal continuum mechanics, including the selection of nonlocal kernel function; nonlocal theory of macro said; Nonlocal viscoelasticity vibration problem of the rod;Nonlocal effect test;Nonlocal theory in the application of the slope stability of the project; Under the dynamic load of nonlocal problems.The concluding remarks are given in Chapter 8. In this paper, the main work and research results are as follows:(1) In order to describe the nonlocal source remaining Further,Introduced two kinds of constitutive relation of the theory of nonlocal.Nonlocal of several common kernel functions are described, and in the nonlocal theory research found that selection index and Gauss kernel function is more reasonable Expounds the nonlocal theory of mass, momentum, momentum and energy balance equation and the normal form of the entropy inequality, nonlocal constitutive relation of the isotropic homogeneous material, the boundary conditions and geometric coordinate equation are given. Using the nonlocal theory in the elastic mechanics, the state of plane stress and the state of plane strain were rewritten.(2) In order to using better the nonlocal theory, based on the calculation model of macroscopic showing a nonlocal effects in this paper,the nonlocal model was established.The main models are nonlocal elastic model,nonlocal viscoelasticity model and nonlocal elastoplastic model.Before modeling, the computing element of the nonlocal effects of stress;the element of the nonlocal belt of stress;the element of nonlocal elastic and the element of nonlocal viscouswere defined.Nonlocal components assembled with the existing computing element,thus the nonlocal model is established and Various models of the constitutive relation is presented.the nonlocal viscoelasticity model was calculated and get the nonlocal constitutive equation in the spatial domain and can use σ(s)= μ(s)ε(s)+f(s) describe. The study found that nonlocal model can use unified constitutive relations, to promote the constitutive equation, the three dimensional viscoelastic model of nonlocal constitutive relation was got.(3) Nonlocal effect experiment and theory simulation.Using polymer materials for test,Loading equipment and data acquisition are designed,and got a number of test data,and the data were analyzed.Using the nonlocal viscoelasticity model has carried on the theoretical calculation to sample,first, the theory model of the control equation is obtained,To control equation for Laplace transformation.Selection of symmetrical type index of kernel function,Under the action of axial force,the theoretical solution of nonlocal strain field was deduced based on the nonlocal Kelvin viscoelastic model. Assuming that the entire test is ideal, this paper argues that the theoretical solution and test results are the same, through this assumption nonlocal material parameters la can be determined.The last, the strain localization phenomenon change rule of sample is given, and on the existing results are compared.(4) Application research of nonlocal viscoelastic plasticity model.Selects Nonlocal elastic model and the nonlocal viscoelasticity model used in the study of longitudinal vibration of bar,The study of the problem is that the main difficulties of the theoretical calculation,used in the calculation of mathematical methods:Laplace transform;method of separation of variables;the transfer function method;Ritz method;vibration mode of orthogonal etc.Under the simple harmonic force load,the solution of the steady-state responses of straight rod are obtained,and the example is verified. Studies have shown that Nonlocal material parameters 1 influence on the vibration frequency is larger.The calculation of straight rod based on the nonlocal viscoelasticity model.Nonlocal material parameters 1 influence on the point amplitude and phase Angle are larger.In addition to use in the bar, also the nonlocal model use in geotechnical slope stability calculation in this paper.Selection of nonlocal elastic models of circular slip surface and the theoretical calculation of arbitrary slip surface in slope,Using the minimum potential energy method to calculate the slope of the minimum sliding displacement and Nonlocal material parameters influence on the stability are discussed,and the influence of soil parameters on the nonlocal.The results show that change the Angle of internal friction is a better way to improve slope stability safety factor.Studies have shown that, By using the nonlocal model calculation stability safety coefficient is less than the local model calculation results of the other methods.The geotechnical engineering design using the nonlocal model for design and calculation, the slope is safer.(5) Under the dynamic load, the soil slope stability based on nonlocal was studied. Selection of circular slip surface as the research object, the article were got the critical slip surface nonlocal normal stress time history curve,nonlocal shear strength time history curve and nonlocal safety factor time history curve. Analysis shows that the dynamic loads had a great influence on the slope stability, and the greater the nonlocal material parameters, the smaller the corresponding coefficient.through the time history analysis method can determine the destruction of the slope and instability.