Modelling of imbibition process in an embankment scale model

This paper aims to investigate the hydro-mechanical behaviour of a loosely compacted embankment during an inundation event. This study is based on the results of a centrifuge test carried out on a small-scale embankment model made of an artificially compacted clay–sand mixture. The wetting-induced displacements are analyzed and interpreted by means of a constitutive model adapted to unsaturated conditions. The numerical predictions are presented in terms of time evolutions of settlements, as well as, spatial distributions of vertical displacements. These profiles are compared to those experimentally observed in order to validate the predictive capabilities of the model on a boundary value problem. Moreover, the stress paths followed by elementary soil elements located at different depths are analyzed to emphasize the stress and strain variations due to capillary rise

Fault & Fracture Development in Foreland Fold and Thrust Belts - Insight from the Lurestan Province, Zagros Mountains, Iran

Second Arabian Plate Geology Workshop Abu Dhabi, UAE, 24 - 27 January 2010The Simply Folded Belt of the Zagros Mountains, Iran, represents one of the best examples of foreland fold and thrust belt. A regional fault and fracture analysis of the Cenomanian ¿ Coniacian Ilam and Sarvak formations, exposed in southern Lurestan Province, is presented as a case study for fault and fracture development in folded belts. The area is characterised by the occurrence of gentle to tight anticlines and synclines whose NW-SE axial traces are parallel to the general trend of the belt. Fold style is intimately related to both vertical and lateral facies distribution. The two formations belong to the Bangestan Group and, in this area, they represent the oldest strata exposed in the core of most anticlines outcropping at surface. Distribution, kinematics and timing of faults and fractures have been characterised through extensive fieldwork and interpretation of orthorectified QuickBird imagery and 3-D virtual outcrop models based on LiDAR technology. Data have been collected from 10 anticlines covering an area of approximately 150 x 150 km. Key outcrops for fracture and fault kinematics interpretations are presented. Field observations and interpretation of QuickBird and 3-D photorealistic models suggest a complex fault and fracture geometry and timing relationship. Both fractures and faults record pre-folding to uplift-related deformations. Pre-folding structures are typically represented by small-scale, flat-ramp-flat geometry thrusts, systematic veins and stylolites, which are superimposed on inherited syn-sedimentary normal faults. Folding-related structures generally reactivated pre-existing fracture and fault planes. Strike-slip faulting is typically recorded as the last faulting event and is probably related to late stage of fold tightening. All structures are geometrically and kinematically consistent with the trend of the Arabian passive margin and its subsequent tectonic inversion. Uplift and stress release induced opening and propagation of through-going fractures. Faults and fracture orientations generally change accordingly with local fold trend. Symmetry between fracture and fold orientation, although commonly interpreted as evidence for folding-related fracture development, is here interpreted as evidence of syn- to post-folding local vertical axis passive rotation

Entanglement Hamiltonians in 1D free lattice models after a global quantum quench

We study the temporal evolution of the entanglement Hamiltonian of an interval after a global quantum quench in free lattice models in one spatial dimension. In a harmonic chain we explore a quench of the frequency parameter. In a chain of free fermions at half filling we consider the evolution of the ground state of a fully dimerised chain through the homogeneous Hamiltonian. We focus on critical evolution Hamiltonians. The temporal evolutions of the gaps in the entanglement spectrum are analysed. The entanglement Hamiltonians in these models are characterised by matrices that provide also contours for the entanglement entropies. The temporal evolution of these contours for the entanglement entropy is studied, also by employing existing conformal field theory results for the semi-infinite line and the quasi-particle picture for the global quench

Characterization of highly frequent epitope-specific CD45RA(+)/CCR7(+/- )T lymphocyte responses against p53-binding domains of the human polyomavirus BK large tumor antigen in HLA-A*0201+ BKV-seropositive donors

Human polyomavirus BK (BKV) has been implicated in oncogenic transformation. Its ability to replicate is determined by the binding of its large tumor antigen (LTag) to products of tumor-suppressor genes regulating cell cycle, as specifically p53. We investigated CD8+ T immune responses to BKV LTag portions involved in p53 binding in HLA-A*0201+ BKV LTag experienced individuals. Peptides selected from either p53-binding region (LTag(351–450 )and LTag(533–626)) by current algorithms and capacity to bind HLA-A*0201 molecule were used to stimulate CD8+ T responses, as assessed by IFN-γ gene expression ex vivo and detected by cytotoxicity assays following in vitro culture. We observed epitope-specific immune responses in all HLA-A*0201+ BKV LTag experienced individuals tested. At least one epitope, LTag(579–587); LLLIWFRPV, was naturally processed in non professional antigen presenting cells and induced cytotoxic responses with CTL precursor frequencies in the order of 1/20'000. Antigen specific CD8+ T cells were only detectable in the CD45RA+ subset, in both CCR7+ and CCR7- subpopulations. These data indicate that widespread cellular immune responses against epitopes within BKV LTag-p53 binding regions exist and question their roles in immunosurveillance against tumors possibly associated with BKV infection

The new Italian public law scholarship

[No abstract available

Hydro-mechanical response of collapsible soils under different infiltration events

International audienc

Hydro-mechanical behavior of an embankment during inundation

The paper presents a comprehensive analysis of the hydro-mechanical response of an embankment subject to inundation. The Modified Cam-Clay model extended to unsaturated conditions and formulated in terms of Bishop’s effective stress is used to predict the mechanical behavior of the sand-clay mixture. The model’s ability to accurately reproduce the embankment response is evaluated by comparing the numerical predictions with the results of the physical model. Time evolution and spatial distribution of the wetting-induced displacements are analyzed together with the stress paths resulting from the imbibition process. The influence of after-compaction conditions on the embankment performance is examined focusing on the occurrence of the volumetric collapse

Modellazione di processi di imbibizione in un rilevato

Lo studio numerico presentato in questa nota è finalizzato alla valutazione degli effetti indotti dall'innalzamento della superficie libera in un rilevato stradale. I risultati presentati si riferiscono alla simulazione di una prova in centrifuga eseguita da Thorel et al. (2011) su un modello di rilevato realizzato in scala 1/100 con una miscela di sabbia e argilla. Gli effetti indotti dai processi di imbibizione per risalita capillare sono analizzati con riferimento, in particolare, alla distribuzione degli spostamenti verticali all'interno del rilevato e alle variazioni di stato di sforzo e deformazione in due elementi posti a diverse profondità