1、附:英文翻译 LIMIT ANALYSIS OF SOIL SLOPES SUBJECTED TO PORE-WATER PRESSURES By J.Kim R.salgado, assoicite member, ASCE ,and H.S., member,ASCE ABSTRACT: the limit-equilibrium method is commonly, used for slope stability analysis. However, it is well known that the solution obtained from the limit-equilibr
2、ium method is not rigorous, because neither static nor kinematic admissibility conditions are satisfied. Limit analysis takes advantage of the lower-and upper-bound theorem of plasticity to provide relatively simple but rigorous bounds on the true solution. In this paper, three nodded linear triangu
3、lar finite elements are used to construct both statically admissible stress fields for lower-bound analysis and kinematically admissible velocity fields for upper-bound analysis. By assuming linear variation of nodal and elemental variables the determination of the best lower-and upper-bound solutio
4、n maybe set up as a linear programming problem with constraints based on the satisfaction of static and kinematic admissibility. The effects of pro-water pressure are considered and incorporated into the finite-element formulations so that effective stress analysis of saturated slope may be done. Re
5、sults obtained from limit analysis of simple slopes with different ground-water patterns are compared with those obtained from the limit-equilibrium method. INTRODUCTION Stability and deformation problem in geotechnical engineering are boundary-value problem; differential equations must be solved fo
6、r given boundary conditions. Solutions are found by solving differential equations derived from condition of equilibrium, compatibility, and the constitutive relation of the soil, subjected to boundary condition. Traditionally, in soil mechanics, the theory of elasticity is used to set up the differ
7、ential equations for deformation problems, while the theory of plasticity is used for stability problems. To obtain solution for loadings ranging from small to sufficiently large to cause collapse of a portion of the soil mass, a complete elastoplastic analysis considering the mechanical behavior of
8、 the soil until failure may be thought of as a possible method. However, such an elastoplastic analysis is rarely used in practice due to the complexity of the computations. From a practical standpoint, the primary focus of a stability problem is on the failure condition of the soil mass. Thus, prac
9、tical solutions can be found in a simpler manner by focusing on conditions at impending collapse. Stability problem of natural slopes, or cut slopes are commonly encountered in civil engineering projects. Solutions may be based on the slip-line method, the limit-equilibrium method, or limit analysis
10、. The limit-equilibrium method has gained wide acceptance in practice due to its simplicity. Most limit-equilibrium method are based on the method of slices, in which a failure surface is assumed and the soil mass above the failure surface is divided into vertical slices. Global static-equilibrium c
11、onditions for assumed failure surface are examined, and a critical slip surface is searched, for which the factor of safety is minimized. In the development of the limit-equilibrium method, efforts have focused on how to reduce the indeterminacy of the problem mainly by making assumptions on inter-s
12、lice forces. However, no solution based on the limit-equilibrium method, not even the so called “rigorous” solutions can be regarded as rigorous in a strict mechanical sense. In limit-equilibrium, the equilibrium equations are not satisfied for every point in the soil mass. Additionally, the flow ru
13、le is not satisfied in typical assumed slip surface, nor are the compatibility condition and pre-failure constitutive relationship. Limit analysis takes advantage of the upper-and lower-bound theorems of plasticity theory to bound the rigorous solution to a stability problem from below and above. Limit analysis solutions are rigorous in the sense that the stress field associated with a lower-bound solution is in equilibrium with imposed loads at every point in the soil mass, while the velocity field associated with an upper-bound solution is compatible with