TY - CONF A1 - Cuéllar, Pablo A1 - Baeßler, Matthias A1 - Rücker, Werner T1 - Relevant factors for the liquefaction susceptibility of cyclically loaded offshore monopiles in sand N2 - The offshore foundations may exhibit a relatively high liquefaction susceptibility due to the full saturation of the porous seabed and the cyclic nature of the typical offshore loads. Here, the particular relevance of some of the main factors that affect the liquefaction susceptibility of an offshore monopile will be addressed, focusing on the possibility of a progressive accumulation of residual pore water pressure within the saturated soil around a monopile under cyclic lateral loading. The discussion is based on numerical results obtained with a coupled FE model of the offshore foundation which includes the Biot-Zienkiewicz u-p model. A constitutive model of the Generalized Plasticity type has been used for the soil in order to reproduce important features of its behaviour under cyclic loading. This paper presents the findings derived from a parametric study of the problem and shows that the accumulation of residual pore pressure can produce significant changes of the pile's behaviour under external loading. The paper also investigates the effects caused by the loading from a realistic storm of moderate magnitude and the consequential transient degradation of the foundation's stiffness. T2 - Poromechanics V - 5th Biot conference on poromechanics CY - Vienna, Austria DA - 10.07.2013 KW - Soil liquefaction KW - Cyclic loads KW - Piles KW - Sand (hydraulic) KW - Offshore structures PY - 2013 SN - 978-0-7844-1299-2 DO - https://doi.org/10.1061/9780784412992.160 SP - 1336 EP - 1345 AN - OPUS4-28873 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bronsert, Jeffrey A1 - Baeßler, Matthias A1 - Cuéllar, Pablo A1 - Rücker, Werner ED - Dimitrovová, Z. ED - de Almeida, J.R. ED - Goncalves, R. T1 - Numerical modeling of train-track-interaction at bridge transition zones considering the long-term behaviour N2 - A train passage will induce elastic and plastic deformations in the ballast and ist underlying soll. Considering the short term behaviour the elastic deformations will overweight the plastic and therefore these can be neglected. Regarding the long term behaviour the plastic deformations will accumulate due to repeating traffic loads and lead to settlement and Deterioration ofthe track structure. A smooth settlement along the track (small differential Settlement) is acceptable, whereas large differential settlement accelerates the process of deterioration and reduces the safety and serviceability ofthe track. Especially a bridge transition zone is prone to large differential settlements, where the track deteriorates in the backfilling area of bridge abutments mainly due to stiffness changes between embankment and bridge, repeating traffic loads and displacements of the superstructure Ends on bridges. A numerical model will be presented, with a particular focus on the long term behaviour of the track at bridge transition zones under repeating traffic loads. The ahn ofthe Simulation is not the computation of every train Crossing but the analysis of the long term behaviour of the bridge transition zone based on single train crossings. The analysis is performed in the time domain, whereas the bridge, the track and the backfilling area are modelled by means of the finite T2 - ICOVP-2013 - 11th International conference on vibration problems CY - Lisbon, Portugal DA - 09.09.2013 KW - Train-track-interaction KW - Transition zone KW - Track settlement PY - 2013 SN - 978-989-96264-4-7 SP - 1 EP - 10 AN - OPUS4-29591 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -