Removal of the membrane penetration error from triaxial data

Niemunis, Andrzej; Knittel, Lukas

doi:10.5802/ogeo.7

Cited by 6 publications

(2 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The application of the stress paths necessitates the cyclic variation of cell pressure, which can lead to membrane penetration effects [28,47]. These were found to be negligible for d 50 = 0.14 mm [33].…”

Section: |X|| = √mentioning

confidence: 98%

“…In case of precompression the soil experienced an isotropic Fig. 1: View of the extraction side of the lignite opencast mine Hambach (left hand side) with a surface of 85 km 2 and depth 400 m created with coal excavator and dumping site (right hand side) [33] compression stress greater than that at the beginning of the subsequent shearing. In the event of preshearing the soil experienced a given deviatoric stress before the subsequent loading.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Influence of recent and long-lasting loading history on the cyclic behaviour of sand: confrontation of novel experimental results and established constitutive laws

Knittel

Tafili

Tavera

et al. 2022

Preprint

View full text Add to dashboard Cite

The design of massive dump slopes for opencast mines usually requires information about the soil resistance to liquefaction during earthquakes. This resistance depends not only on the initial stress, the initial density, and the amplitude of the cyclic loading, but also on the preshearing, that is, the deviatoric stress path applied to the soil before the cycling loading. To explore the influence of preshearing on the subsequent soil behaviour, a set of triaxial tests with a combination of undrained preshearing and drained stress cycles using two sample preparation methods is presented. It is shown that the preshearing as well as the preparation method have a mayor influence on the strain accumulation upon cyclic loading. Simulations of the experiments with four advanced constitutive models reveal that neither the long-lasting effect of preshearing nor the preparation method can adequately be captured by all of the models. This deficiency of the constitutive models can lead to unsafe designs due to the overestimation of the cyclic resistance to liquefaction and to the underestimation of long term settlements.

show abstract

Section: |X|| = √mentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Influence of recent and long-lasting loading history on the cyclic behaviour of sand: confrontation of novel experimental results and established constitutive laws

Knittel

Tafili

Tavera

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

Complex High‐Cyclic Loading in an Accumulation Model for Sand

Staubach,

Knittel,

Wichtmann

2024

Num Anal Meth Geomechanics

View full text Add to dashboard Cite

Experimental evidence indicates that multidimensional cyclic loading of soils causes larger accumulation of deformations than equivalent one‐dimensional loading. The response of sand to high‐cyclic loading with 10,000 cycles and up to four‐dimensional stress paths (i.e., four independent oscillating components) is examined in 120 triaxial and hollow cylinder tests in this work to extend these findings. With increasing number of oscillating stress components, the accumulation of permanent strains tends to increase. It is demonstrated that the definition of the multidimensional strain amplitude incorporated in the high‐cycle accumulation (HCA) model can account for this. The validation of the HCA model for complex cyclic loading is complemented by the simulation of model tests on monopile foundations of offshore wind turbines subjected to multidirectional cyclic loading, for which the consideration of spatially variable cyclic loading with nonconstant load amplitudes in the HCA model is discussed. For this purpose, an extension of the HCA model considering multiple strain amplitudes is presented.

show abstract

Pure cross-anisotropy for geotechnical elastic potentials

Niemunis

Staszewska

2021

Acta Geotech.

Self Cite

View full text Add to dashboard Cite

The pure cross-anisotropy is understood as a special scaling of strain (or stress). The scaled tensor is used as an argument in the elastic stiffness (or compliance). Such anisotropy can be overlaid on the top of any elastic stiffness, in particular on one obtained from an elastic potential with its own stress-induced anisotropy. This superposition does not violate the Second Law. The method can be also applied to other functions like plastic potentials or yield surfaces, wherever some cross-anisotropy is desired. The pure cross-anisotropy is described by the sedimentation vector and at most two constants. Scaling with more than two purely anisotropic constants is shown impossible. The formulation was compared with experiments and alternative approaches. Static and dynamic calibration of the pure anisotropy is also discussed. Graphic representation of stiffness with the popular response envelopes requires some enhancement for anisotropy. Several examples are presented. All derivations and examples were accomplished using the algebra program Mathematica.

show abstract

Removal of the membrane penetration error from triaxial data

Cited by 6 publications

References 23 publications

Influence of recent and long-lasting loading history on the cyclic behaviour of sand: confrontation of novel experimental results and established constitutive laws

Influence of recent and long-lasting loading history on the cyclic behaviour of sand: confrontation of novel experimental results and established constitutive laws

Complex High‐Cyclic Loading in an Accumulation Model for Sand

Pure cross-anisotropy for geotechnical elastic potentials

Contact Info

Product

Resources

About