Computers and Geotechnics 9 (1990) 233-237

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GEOMATERIALS: Constitutive equat/ons and ModeWng

FA. F. Darve

£ / .~ le r Science PuMs/m's, 1990

ISBN: 1 8.$166 3843

A considerable research effort devoted by researchers to develop accurate and powerful

numerical tools during the last decade has been accompanied by a spectacular drop in

the prices of computers. Consequently, computer programs have become widely available

to engineers, who can model physical phenomena in a more precise way. Ho~,~ver,

accuracy of computer predictions will never be better than the description of the behaviour

of materials involved in the problem.

This is the challenge faced by "Geomateriais: Constitutive Equations and Modelling", which

aims to provide both practising engineers and researchers with an up-to-date state of the

art .

The book is a revised version of "Manuel de rh~ologie des g~omateriaux" which was

published in French in 1987 by Presses de l'Ecole Nationale des Ponts et Chaus,~es.

Several improvements have been made, among which it is worth mentioning the

introduction of a new chapter on "Damage Fracture and Size Effects in Concrete", where

the macroscopic behaviour of concrete is related to the development and growth of

microcracks and their localization in narrow zones. First stage is analysed in terms of

continuous damage mechanics and fracture mechanics is used for the second.

The structure of the French edition has been kept and the book is divided into four

parts, devoted to:

(i)

(ii) (iii) (iv)

Behaviour of Oeomaterials

Constitutive equations

Micro- and macro-structural behaviour

Computational methods

It is interesting to notice that the authors have aimed at producing a unifying description

of soils, rocks and concrete behaviour, highlighting those common features exhibited by

them, such as the existence of irreversible strain at very low stress levels, the changes of

233 Computers and Geotechnics 9 (1990)--~ 1990 Elsevier Science Publishers Ltd, England, Printed in Great Britain

234

volume caused by rearrangement of the microstructure or the dependence on the first

inveriant of the stress tensor.

Laboratory devices such as triaxial, true triaxial or hollow cylinder apparatuses are

described in part one, together with the analyses of the stress paths which can be applied

and some examples of experimental results.

The chapter on viscous properties of geomateriais has been enlarged in this new edition

which now includes the mathematical modelling of time dependent behaviour.

This fh'st part of the book is complemented by two contributions describing the behaviour

of geotextiles and the experimental simulation of geotechnical structures, where details

about centrifuge modelling are given.

Once the behaviour of geomaterials has been covered the reader may proceed to the

second part, which is devoted to constitutive modelling of both plastic and viscoplastic

materials. The authors have aimed here not only at providing a theoretical background

but at classifying and establishing the range of application of the existing models, using

the concept of tensorial zone. Next a complete analysis of classical and multimechanism

theories of plasticity is given and a chapter is devoted to some recent apportations of

Grenoble school in the field of incrementally non-linear constitutive relationships.

One problem which has become a focal point of attraction during the past years is that of

localization of strain in shear bands, and the reader can find a chapter where these

phenomena are analysed, both from the experimental and the theoretical point of view.

This chapter is included in part three, which is devoted to the relationships between

material microstructure and behaviour, and where explanation of theories such as

homogeneization may be found.

Last part of the book is devoted to describe the theoretical basis of numerical methods in

geomechanics. It is of special interest that the last chapter is addressed to the problems

of dynamic behaviour of geomateriais.

In conclusion, the book will prove to be a most valuable reference for both researchers

and engineers interested in constitutive modelfing of geomateriais.

M.P.