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Ultimate Bearing Capacity (ultimate + bearing_capacity)
Selected AbstractsBearing capacity of two interfering footingsINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 3 2008Jyant Kumar Abstract By using an upper bound limit analysis in conjunction with finite elements and linear programming, the ultimate bearing capacity of two interfering rough strip footings, resting on a cohesionless medium, was computed. Along all the interfaces of the chosen triangular elements, velocity discontinuities were employed. The plastic strains were incorporated using an associated flow rule. For different clear spacing (S) between the two footings, the efficiency factor (,,) was determined, where ,, is defined as the ratio of the failure load for a strip footing of given width in the presence of the other footing to that of a single isolated strip footing having the same width. The value of ,, at S/B = 0 becomes equal to 2.0, and the maximum ,, occurs at S/B = ,Scr/B. For S/B,Scr/B, the ultimate failure load for a footing becomes almost half that of an isolated footing having width (2B + S), and the soil mass below and in between the two footings deforms mainly in the downward direction. In contrast, for S/B>Scr/B, ground heave was noticed along both the sides of the footing. As compared to the available theories, the analysis provides generally lower values of ,, for S/B>Scr/B. Copyright © 2007 John Wiley & Sons, Ltd. [source] Load-displacement and bearing capacity of foundations on granular soils using a multi-surface kinematic constitutive soil modelINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 9 2006M. Banimahd Abstract A finite element approach based on an advanced multi-surface kinematic constitutive model is used to evaluate the bearing capacity of footings resting on granular soils. Unlike simple elastic-perfectly plastic models, often applied to granular foundation problems, the present model realistically accounts for stress dependency of the friction angle, strain softening,hardening and non-associativity. After the model and its implementation into a finite element code are briefly discussed, the numerical difficulty due to the singularity at the footing edge is addressed. The bearing capacity factor N, is then calculated for different granular materials. The effect of footing size, shape, relative density and roughness on the ultimate bearing capacity are studied and the computed results compare very favourably with the general experimental trends. In addition, it is shown that the finite element solution can clearly represent counteracting mechanisms of progressive failure which have an important effect on the bearing capacity of granular foundations. Copyright © 2006 John Wiley & Sons, Ltd. [source] A homogenization method for estimating the bearing capacity of soils reinforced by columnsINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 10 2005B. Jellali Abstract The ultimate bearing capacity problem of a strip foundation resting on a soil reinforced by a group of regularly spaced columns is investigated in the situation when both the native soil and reinforcing material are purely cohesive. Making use of the yield design homogenization approach, it is shown that such a problem may be dealt with as a plane strain yield design problem, provided that the reinforced soil macroscopic strength condition has been previously determined. Lower and upper bound estimates for such a macroscopic criterion are obtained, thus giving evidence of the reinforced soil strong anisotropy. Performing the upper bound kinematic approach on the homogenized bearing capacity problem, by using the classical Prandtl's failure mechanism, makes it then possible to derive analytical upper bound estimates for the reinforced foundation bearing capacity, as a function of the reinforced soil parameters (volume fraction and cohesion ratio), as well as of the relative extension of the reinforced area. It is shown in particular that such an estimate is closer to the exact value of the ultimate bearing capacity, than that derived from a direct analysis which implicitly assumes that the reinforced soil is an isotropic material. Copyright © 2005 John Wiley & Sons, Ltd. [source] Cyclic macro-element for soil,structure interaction: material and geometrical non-linearitiesINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 13 2001Cécile Cremer Abstract This paper presents a non-linear soil,structure interaction (SSI) macro-element for shallow foundation on cohesive soil. The element describes the behaviour in the near field of the foundation under cyclic loading, reproducing the material non-linearities of the soil under the foundation (yielding) as well as the geometrical non-linearities (uplift) at the soil,structure interface. The overall behaviour in the soil and at the interface is reduced to its action on the foundation. The macro-element consists of a non-linear joint element, expressed in generalised variables, i.e. in forces applied to the foundation and in the corresponding displacements. Failure is described by the interaction diagram of the ultimate bearing capacity of the foundation under combined loads. Mechanisms of yielding and uplift are modelled through a global, coupled plasticity,uplift model. The cyclic model is dedicated to modelling the dynamic response of structures subjected to seismic action. Thus, it is especially suited to combined loading developed during this kind of motion. Comparisons of cyclic results obtained from the macro-element and from a FE modelization are shown in order to demonstrate the relevance of the proposed model and its predictive ability. Copyright © 2001 John Wiley & Sons, Ltd. [source] Nonlinear FEM Simulation of Air Cushion Vehicle (ACV) Skirt Joint Under Tension LoadingNAVAL ENGINEERS JOURNAL, Issue 2 2009JIA ZHOU The mechanical properties of an air cushion vehicle (ACV) skirt cloth, which is a nonlinear rubber-coated fabric, are tested on a Series IX 4465 electron tension machine manufactured by Instron Company. Compared with the Mooney,Rivlin and Ogden form, the second-order Mooney,Rivlin form agrees with the model test result better. The ultimate bearing capacity of an ACV skirt joint structure is tested on a mechanical tension machine and the ultimate load is recorded manually. Then, considering the contact effect of each assembly and the large-displacement of skirt elements, a nonlinear finite element method (FEM)-based simulation process of an ACV skirt joint structure under tension loading is presented. The simulation process comprises three steps: assembly of parts, bolts' tightening, and tensioning the skirt cloth. Under these loadings, the stress distribution and deformation of the skirt cloth, and the cloth broken locations and directions are obtained. These results agree well with the test results. As for the ultimate bearing capacity of the skirt joint, the simulation result is slightly smaller than the test result. Thus, this FEM-based simulation method is proven to be reliable and relatively conservative. [source] | ||||||||||