Study On Interval Analysis Theory And Its Application In Slope Engineering

Rock mass is a highly complicated uncertain and unknown system. There is certain fuzziness and limitation to know it. So its mechanical parameters, constitutive model, computation load, boundary condition (in-siu stress, etc) and the measured displacement and stress can not exactly be determined. The indefinite analysis method in recent years is always an important research topic in the project. Varies of uncertain analysis methods used in the area of engineering is reviewed in this thesis. The feasibility and validity of interval analysis technique applied in geotechnical engineering are studied as a key point. The main study works focus on the following several aspects:1. Interval variables are adopted for denoting the uncertain parameters in engineering. For interval expanding problem in interval analysis, interval parameter perturbation method based element are presented to solve the equation of interval FEM on the basis of the thorough research to interval finite element equation solution. The method is compared with the other ones in a computed example. The researched results have shown that the method is simple and valid.2. Taking into account the basic equations and the minimum interval potential energy in elastic mechanics, the control equation of interval finite element method about a two-dimensional problem was set up. Combined the construction model with interval FEM, the interval stiffness matrix and interval load vector are obtained from the interval parameters and then the interval problem are described. Taken into account dependence of the element stiffness and the element load vector, the element parameters perturbation method is presented to solve the element stiffness matrix and the element load vector, then gather to form the general matrix and the general load vector. The interval displacement and interval stress are obtained for the method.3. On the basis of interval displacement and interval stress, optimization method is presented to obtain the most dangerous landslide. Interval variables are adopted for denoting the uncertain material parameters. Interval safety factor is obtained on the basis of the safety factor definition of slope based interval finite element method.4. The limit equilibrium analysis of slope is also developed as a interval analysis method with the consideration of mechanical parameters as a interval number in the equilibrium equation. Interval method of slope analysis is developed in this thesis based on the interval algorithm. The corresponding equations are also put forward for the stability analysis of slope. On the bases of statistic datum interval evaluationcriteria of slope stability are proposed in the end.5. ANN is present to simulate initial stress. Combined interval variables with ANN, interval ANN is set up. And interval ANN is presented to solve the uncertain of initial stress field.6. Because of the shortage of traditional ANN in application, combined ANN and simulated annealing algorithm method can overcome the shortage of poor local search ability. This method can be used to solve the inverse problem in slope engineering.7. The interval displacement back analysis model is set up in the slope engineering. The interval inverse back analysis is worked out in the initial stress field.8. Analysis and validation are applied to the slope of LongTan hydropower station and the GuShuBao landslide, which accomplish the most important purpose that research productions should be applied to practice.