摘要:

AbstractIn this paper, liquefaction potential of loose sand deposit subjected to an earthquake loading is evaluated. The analysis is performed by using a finite element technique incorporating the equations of dynamics of saturated porous elastoplastic media. The soil response is modelled by an anisotropic hardening rule, similar to that as proposed by Poorooshasb and Pietruszczak.1The concept is based on the theory of bounding surface plasticity incorporating a non‐associated flow rule and the idea of reflected plastic potential. The present paper provides a modified formulation to that discussed in Reference 1. Modifications are aimed at simplifying the concept for numerical implementation

ISSN:0363-9061    

DOI:10.1002/nag.1610110302

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractVariational principles governing dynamics of fluid‐saturated linear elastic porous media are derived. Complementary as well as direct formulations are discussed. Discontinuities in the field variables, the approximation space and the excitation are allowed for. Extensions of the variational principles to relax smootheness requirements on certain field variables are introduced along with some specizalizations convenient for finite element application

ISSN:0363-9061    

DOI:10.1002/nag.1610110303

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractAn approximate, analytical solution is found for the gravity‐induced stresses in the neighbourhood of an axisymmetric topographic feature on an elastic half‐space. The solution is in the form of a perturbation expansion in powers of the characteristic slope, ϵ. The leading order problem, atO(1), is for a distributed normal load on a plane half‐space. TheO(ϵ) correction is due to a distributed shear traction. The vertical variation of the near‐surface stress perturbation and the rotation of the principal stress directions areO(ϵ) effects, and thus include contribution s of like order from both the normal and shear loads. The method requires general solutions for axisymmetric, normal and shear tractions of arbitrary radial distribution, and these are found in terms of Hankel

ISSN:0363-9061    

DOI:10.1002/nag.1610110304

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThe behaviour of an under‐reamed anchor in a consolidating soil is examined by approximating the anchor as an impermeable circular plate embedded in a deep soil layer. Hankel and Laplace transforms are applied to the equations governing the consolidation process, and this greatly simplifies the equations, allowing a solution to be obtained for the transformed variables. Numerical inversion of both the Hankel and Laplace transforms is used to obtain the solution at any time.A particular feature of the solution method is that the unknown contact stress between the anchor and the soil and the unknown flows in the plane of the anchor are approximated as a series of simple functions with unknown coefficients. By determining the coefficients of the terms in the series, the complete solution may be found.Computations have been carried out using the method proposed, and results are presented for the time–settlement behaviour of an impermeable anchor. These results are compared with some published and some recomputed finite element data, and this highlights some of the difficulties encountered in using such numerical techniq

ISSN:0363-9061    

DOI:10.1002/nag.1610110305

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractA finite element, variable mesh analysis of unconfined steady‐state seepage problems is presented based on a nonlinear programming algorithm. It is shown that the minimization of an objective function which merely represents a measure of the total flux leaving or entering the mesh at the free surface nodes (except those that belong also to pervious boundaries) does not permit a unique definition of the free surface geometry. This problem, which is apparently related to the numerical instabilities often met when using variable mesh approaches, can be eliminated by adding to the objective function a term representing a sort of overall ‘regularity’ condition for the shape of the free surface. The modified solution procedure turns out to be stable and able to provide meaningful results for practical problems even when rather coarse meshes are ad

ISSN:0363-9061    

DOI:10.1002/nag.1610110306

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractAn approach is presented for the prediction of linear and nonlinear load–deformation behaviour of laterally loaded pile groups. The individual pile response is obtained by the conventionalp–ycurve technique, while group interaction is modelled using the Mindlin's solution. Good agreement is observed when comparing the present method of analysis with the commonly used interaction factor approach for the computation of response of pile groups embedded in a homogenous, isotropic elastic half‐space. The predicted pile group behaviour also compares favourably with existing field data on laterally loaded pile groups in soft

ISSN:0363-9061    

DOI:10.1002/nag.1610110307

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThe stress solution in plasticity with an associated or a non‐associated flow rule is considered. Upon fully implicit integration of the relevant constitutive relations the stress is obtained as the projection of the (fictitious) elastic stress onto the yield surface for given values of the hardening softening variables. This projection is defined, for a general non‐associated flow rule, in adjusted complementary elastic energy, which becomes exactly the complementary energy when the flow rule is associated.Isotropic elasticity and mean‐stress dependent isotropic yield criteria (pertinent to soil) are considered and the implications of a certain class of non‐associated flow rules are evaluated. This class relates to dilatant (or contractant) materials and involves non‐associated plastic volume change. The corresponding stress solutions are shown to be strongly influenced by Poisson's ratio and by the dilat

ISSN:0363-9061    

DOI:10.1002/nag.1610110308

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610110309

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610110301

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY