Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Studia Geotechnica et Mechanica

2 2008

Powiadomienia systemowe

Sesja wygasła!
Sesja wygasła!

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Prise en compte de l'effet de la mise en place dans la modélisation numérique en 3D des colonnes ballastées dans l'argile molle

Nguyen N. T., Foray P., Flavigny E.

Studia Geotechnica et Mechanica

2008

Vol. 30, nr 1-2

189-198

This paper presents a comparison of numerical modelling of the behaviour of reinforcements in the form of stone columns in very soft clay. The simulation is run using the software finite elements Plaxis, first in 2D, then in 3D. We are particularly interested in taking into account the application of the columns in modelling. Indeed, in practice, due to the expansion of the column, the ground in its close vicinity undergoes a lateral compaction and the horizontal stresses are increased. This lateral expansion of the stone column can be simulated numerically, with the values of volume deformation which correspond to those observed in practice, and which can be connected with those usually adopted for the ratio between the modulus of the column and the reinforced ground. It is shown that this expansion induces a significant decrease in the stone columns.

Modélisation constitutive du comportement cyclique des sables en condition drainée

Messast S., Boulon M., Flavigny E., Labanieh S.

Studia Geotechnica et Mechanica

2008

Vol. 30, nr 1-2

131-137

Considerable strains appear in the structures at the time of the irreversible strains accumulation of the foundation soil under the effect of the cyclic loads. If the number of cycles is very high even "small strains" after accumulation become important and sometimes harmful. In this study, a simple numeric modelling of the behaviour of the sands under cyclic loading is proposed. The proposed approach attempts, in drained condition, to determine the parameters characterizing the average cyclic path of soil under the effect of N cycles duly characterized, and to explain the cyclic effect by an accumulated volumetric strain as well as by a variation of the soil modulus. In this survey, triaxial cyclic tests are simulated by means of a calculation by Finite Elements Method using the Plaxis program. The determination of identification parameters of the first cycle (load-unload) realised step-by-step was achieved by taking the HSM model as the behaviour model of soil. Then the behaviour after N cycles (N > 103) is simulated by the proposed formulation as a pseudo-flow. The comparison of the proposed method to several triaxial cyclic tests confirms the good adaptation of the proposed model to this type of problems.