Bengt H. Fellenius

Pile Dynamics in Geotechnical Practice—Six Case Histories

Six cases are presented showing the benefit of dynamic testing and analysis of driven piles, comprising (1) a comparison between two types of piles and a correlation between CAPWAP determined capacity and load-movement response to that determined in a static loading test, (2) the benefit of time-dependent increase of pile capacity, (3) a study how a soil plug can be shown to replace a pile shoe, (4 & 5) the effect on pile capacity from removing soil inside the pile, (6) set-up and effect of excavation. Together the cases show that the dynamic testing can be used to investigate problems in design and construction of piles much beyond a simple capacity determination.

Finite element validation of a bounding surface plasticity model

Abstract A bounding surface plasticity model for cohesionless soils is validated with respect to two boundary value problems. In the first boundary value problem, the behavior of a model-scale footing resting on the surface of a sandy silt is analyzed. Whereas, in the second boundary value problem, the finite element simulations are compared with the behavior of the Leighton Buzzard Sand in the Cambridge Simple Shear Device. The validation of the constitutive model also included the predictions of the behavior of a sandy silt in a true triaxial apparatus following stress paths different from those used in the calibration of the constitutive model. Comparisons of the model predictions with the test results considered here show the validity of the constitutive model and its ability to simulate the soil behavior in a variety of loading conditions.

Finite element applications of a bounding surface plasticity model

Bardets bounding surface plasticity model was used to analyze two different boundary value problems: the load-displacement responce of a model-scale footing resting on the sur-face of a sandy silt, and the behaviour of the Leighton Buzzard Sand in the Cambridge Simple Shear Device. Comparisons between experimental observations and the results of the finite element analyses proved the ability of the constitutive model to simulate accurately the soil behaviour in boundary value problems.