摘要:

AbstractMost deposited sands exhibit anisotropic behaviour. A plasticity model has been proposed with the capacity for simulating such anisotropic behaviour. The proposed model contains a number of coefficients of anisotropy. Methodology for determination of the coefficients of anisotropy has been discussed. Using experimental data, the coefficients of anisotropy have been determined for a number of well‐known sands. Stress‐dilatancy has been modelled by using the ‘normalized work’ and it has been shown that the normalized work is independent of inherent anisotropy. Finally, some reasonably close comparisons between experimental results and model simulations have been r

ISSN:0363-9061    

DOI:10.1002/nag.1610080102

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe idea of using a thin solid element, called a thin‐layer element, in soil‐structure interaction and rock joints is proposed. A special constitutive model is used and various deformation modes such as no slip, slip, debonding and rebonding are incorporated. The shear stiffness is found from special laboratory tests and the normal stiffness is assumed to be composed of participation of the thin‐layer element and the adjoining solid elements. A parametric study shows that the thickness of the thin‐layer element can be such that the ratio of thickness to (mean) dimension of the adjacent element is in the range of 0.01 to 0.1. A number of simple and practical problems are solved to illustrate the success of the thin‐layer element for soil‐structure interacti

ISSN:0363-9061    

DOI:10.1002/nag.1610080103

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe work presents an exact expression for the Hankel transform of the surface displacement of a rigid circular body performing harmonic vertical vibrations on a homogeneous elastic half‐space of arbitrary Poissn'S ratio interrupted at some depth by a frictionless horizontal plane. The limiting case of the uninterrupted half‐space is recovered in each of the extreme cases when the frictionless plane coincides with the surface or sinks to an infinite depth. Furthermore, the static case is derived in the limiting case of zero frequency and it is shown that the result agrees with the limiting case of zero gradient shear modulus variation for the static case of the incompressible non‐homogeneous half‐space.It is also established that Poisson'S ratio effect is linear, and the important proposition is again sustained that only surface shear modulus dominates vibrations on elastic media whereas any other factor such as the interruption of the frictionless plane as in the present case, merely constitutes a negligible secondary pa

ISSN:0363-9061    

DOI:10.1002/nag.1610080104

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe paper deals with the propagation of shock waves at the surface of soils. Heterogeneity and damping are introduced into analytical half‐space solutions. The suggested model explains two phenomena, often observed with shock propagation in actual soils, that differ from the behaviour of the homogeneous half‐space: the pronounced decay of the disturbances with distance and the elongation of the disturbance into a train of waves. The effects of heterogeneity and damping are discussed quantitatively.The response of footings on heterogeneous soils has been investigated by several authors. Awojobi4considered the Gibson soil in which the shear modulus increases linearly with depth. Luco5and Gazetas and Roesset6investigated a multi‐layered soil, the shear modulus being constant within each layer. Gazetas7, using a technique suggested by Gupta8extended this method to layers with linearly varying shear modulus. Little work is available on the propagation of waves in heterogeneous bodies. Some results concerning the modes and the mode shapes in heterogeneous soils were reported by Ewing, Jardetzky and Press9and Bath.10The modes have to be superposed in an appropriate way to obtain the displacement field at the surface. This has been approximately achieved by the finite element formulations of Lysmer,11, Lysmer and Waas12and Waas.13Auersch14applied this method to a homogeneous layer on a rigid base. He found some dispersion of the Rayleigh wave within a narrow frequency range. Finite elements combined with discrete Laplace transforms, however, consume much computer time. Rao and Goda15and Rao16calculated surface vibrations of a half‐space with exponentially varying shear modulus and density. Their method is similar to Lamb'S1procedure for the homogeneous half‐space. Only one mode–the Rayleigh wave–occurs in their heterogeneous half‐space. The examples show the considerable effect of heterogeneity on wave propagation. In the present paper, more general variations of the shear modulus

ISSN:0363-9061    

DOI:10.1002/nag.1610080105

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe basic equations of motion for porous media were established by Biot and despite many subsequent rederivations, are, with minor modifications, relevant today. However, some changes of variables and approximations are on occasion useful, and this paper discusses the alternative forms available and their relative efficiency of solution in the numerical context. Here penaity methods prove once again useful. The paper is illustrated with examples covering phenomena of different periods ranging froms hock excitation to slow consolidation which are treated in a single unified program.

ISSN:0363-9061    

DOI:10.1002/nag.1610080106

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610080107

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610080101

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY