摘要:

AbstractThe dynamic behaviour of road structure has been analysed by idealizing the subgrade with different viscoelastic models having three and four elements. Complex Fourier transformation has been used to solve the resulting differential equations. The results are presented in non‐dimensional form. A detailed study has been made to determine the effect of different parameters on the deflection and moment of the pavement. Also, the relative implications of idealizing the subgrade with different viscoelastic models have been studied. A numerical example has been solve

ISSN:0363-9061    

DOI:10.1002/nag.1610060403

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractThe factor of safety used in designing pile foundations for vertical load should depend on three things, prior information on load capacity summarized by empirical correlations with load capacity models, site specific information derived from load tests, and an objective function reflecting economic and safety considerations. A statistical approach to factor of safety selection was developed in order to suggest improvements of current standards for driven pile design. This approach recognizes a distinction between the variability of pile load capacity within individual sites, and the global variability upon which model correlations are based. Charts have been prepared for determining the FS required to achieve specified reliability indices, as a function of the number of load tests at a particular site and their outcomes.

ISSN:0363-9061    

DOI:10.1002/nag.1610060404

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractThe paper is concerned with the finite‐element modelling of geologic phenomena. More specifically, the paper presents numerical models of folding and sait doming. A (penalty‐) finite‐element model based on the equations governing a viscous incompressible fluid is used to simulate the folding is used to simulate the folding of a viscous layer in a less viscous matrix and the salt dome formation, and to predict the location of active faulting and deformation in prograding delta systems on continentalmargins. The initiation and development of drape folding and associated faulting are also modelled. The United States continental margin of the Gulf of Mexico is used as an example of prograding delta system. The finite‐element predictions seem to agreewith the published

ISSN:0363-9061    

DOI:10.1002/nag.1610060405

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractThe present study is a continuation of the numerical modelling of geologic structures by the authors (see J. N. Reddyet al., Finite‐element modelling of folding and faulting, this journal). The present paper is concerned with the computation of the stress and fracture density distributions in single layer folds by the finite‐element method. It was found that variations in fracture patterns are related to several variables: (i) the viscosity of the competent layer, (ii) the ratio of the viscosity of the competent layer to the viscosity of the matrix, (iii) the cohesive strength of the material, and (iv) the boundary velocities during deformation. The fracture prediction is based on the Mohr–Coulomb criterion, which is a function of the stresses only. Prediction of fracture density is based on a function of the strain energy. It is found that there is a good correlation between the computer predicted fractures and the fracture pattern produced by the expermental buckiing of rock‐beams. Itis, concluded that the viscosity ratio controls the location of fractures in single laye

ISSN:0363-9061    

DOI:10.1002/nag.1610060406

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractThis paper draws attention to the great influence certain types of discontinuities in foundation rock masses can have on dam design. By means of two practical examples, the role of numerical procedures in the solution of stability and deformation problems posed by foundation heterogeneities is discussed and emphasized. Some basic theoretical considerations regarding the limit‐states and the concept of safety to be used in dam design are also presented as a complement to the analyses description.The case of the Ãgua Vermelha dam, recently built in southern Brazil, is the subject of the first example. Here, a major joint in the basaltic foundation was the decisive geological feature for the stability analyses which were performed by means of the finite element method. The second example refers to the Itaipu dam, a record‐breaking Brazilian–Paraguayan hydroelectric development. Marked sub‐horizontal discontinuities between lava flows, greatly reducing the strength and stiffness of the basaltic rock masses, were of main concern in this case. The results of the foundation studies, with due help of numerical procedures, called for the construction of concrete shear keys, in order to achieve a satisfactory margin of structura

ISSN:0363-9061    

DOI:10.1002/nag.1610060407

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610060408

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610060410

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610060402

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY