摘要:

AbstractThis paper presents an approximate method of numerical analysis of piled–raft foundations in which the raft is modelled as a thin plate and the piles as interacting springs of appropriate stiffness. Allowance is made for the development of limiting pressures below the raft and of the ultimate axial load capacity of the piles.Comparisons between this analysis and existing solutions verify that, despite the approximations involved, the analysis can provide solutions of adequate accuracy for the settlement and pile load distribution within a piled raft.Comparisons are also made with the results of a series of centrifuge tests and with measurements of the performance of a full‐scale piled raft. In both cases, the analysis predicts very well the settlement and proportion of load carried by the pi

ISSN:0363-9061    

DOI:10.1002/nag.1610180202

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThis paper is concerned with the behaviour of granular media containing voids penetrated by a mixture of viscous liquid and gas (air). It is assumed that, for such materials, the skeleton may be considered as rate‐independent and the sensitivity to the applied loading rate may be attributed to the viscosity of the liquid filling the void space. Within the context of geomechanics, such assumptions appear to be relevant to all coarse‐grained cohesionless materials, including saturated sands. A mathematical formulation for the description of undrained response is presented. The macroscopic properties are estimated based on volume averaging, which is applied to both stress and strain measures within the heterogeneous constituent medium. Numerical examples are provided illustrating the influence of the viscosity of the liquid on the liquefaction potential of a loose granular assem

ISSN:0363-9061    

DOI:10.1002/nag.1610180203

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractA matrix relating stress and elastic strain tensors for anisotropic particulate materials has been derived. The magnitude of the matrix depends on the state of the material anisotropy. Anisotropy in granular materials depends on strain because normal and tangential particle contact forces, as well as the spatial distribution of the contacts, vary with stress and strain. However, the rotation tensor and the strain tensor cannot be independent; they must satisfy certain constraints to meet the requirement for macroscopic stress tensor symmetry. These conditions and constraints lead to the derivation of the matrix presented in this article. The principal directions of the stress tensor and strain tensor are generally not coincident, and the values of deformation parameters, Young's modulus and Poisson's ratio, are direction dependent; these two aspects are also discussed in this paper. Whereas this matrix can be used in static numerical analyses for elastic problems, we note that this relationship can also be used as a basis upon which to derive a fully incremental stress–strain relationship for anisotropic granular materials in the plastic state, where the anisotropy is evolving with strai

ISSN:0363-9061    

DOI:10.1002/nag.1610180204

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractDue to rock bursting or blasting, violent rock ejections can occur. In underground excavations, rockbolts are often used to retain rock blocks that otherwise would be ejected. Employing the stress wave approach, general formulae are derived to compute the elastic stress waves in rockbolts subject to rock block impact loading. Weight‐drop tests on steel rods, simulating impact loading of rockbolts, were performed, and a reasonable agreement is found between theoretical predictions and experimental results. The elastic stress wave in an impact loaded steel rod consists of a rider wave and a lower‐frequency carrier wave. With the same drop height, the carrier wave becomes more sinusoidal as the mass ratio of steel rod to drop weight is decrea

ISSN:0363-9061    

DOI:10.1002/nag.1610180205

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe CamClay model has been extensively used in numerous research programmes for constitutive modelling in Soil Mechanics during the past quarter of a century. Several derivations of this model are now available and routinely used for numerical simulations in the geomechanical engineering field. However, to the authors' knowledge the thermodynamical basis of this model in its original form has never been established, at least in a modern thermodynamics framework. The thermodynamics principle proposed by Ziegler is very expedient for this purpose as the non‐associated flow rule may be considered. This approach is applied to the CamClay model with the Roscoe dilatancy rule. A dissipation function and free energy are specified in terms of kinematic variables (i.e. state and internal variables), and the material response is derived entirely from these function

ISSN:0363-9061    

DOI:10.1002/nag.1610180206

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610180207

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610180208

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610180201

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY