Ratcheting convective cells of sand grains around offshore piles under cyclic lateral loads

Cuéllar, Pablo; Baeßler, Matthias; Rücker, Werner

doi:10.1007/s10035-009-0153-3

Cited by 53 publications

(23 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The results show that, in piles subjected to combination of vertical and cyclic lateral loading, there is a considerable decrease in the lateral displacement under increasing the vertical load levels as compared to the pure cyclic lateral load case. Under these conditions, the combined loading on piles induces interaction effects due to simultaneous mobilization of passive earth pressure due to cyclic lateral loads and pile skin friction due to vertical load [27]. Alternatively, this issue has another interpretation; the increase in the lateral capacity of free-head piles installed in sandy soil due to the presence of vertical loads is attributed to the increase in the confining pressures in the sand deposit surrounding the upper part of the pile [3,4].…”

Section: Resultsmentioning

confidence: 99%

“…The dilation phenomenon was explained [29], especially for the dense sands at low confining stress, where particle overriding (and hence dilation) rather than particle crushing might be expected. It seems unlikely that the densification could account for the steady grain migration throughout the whole test, so the soil densification should have a specific limit [27]. Heaving of sand also occurs on either side of the piles at the ground surface.…”

Section: Effect Of Number Of Cycles Of Loading On Load Lateral Displamentioning

confidence: 99%

See 1 more Smart Citation

Lateral Response of a Single Pile under Combined Axial and Lateral Cyclic Loading in Sandy Soil

Kahribt

Abbas

2018

CivileJournal

View full text Add to dashboard Cite

According to practical situation, there have been limited investigations on the response of piles subjected to combined loadings especially when subjected to cyclic lateral loads. Those few studies led to contradictory results with regard to the effects of vertical loads on the lateral response of piles. Therefore, a series of experimental investigation into piles in dense sand subjected to combination of static vertical and cyclic lateral loading were conducted with instrumented model piles. The effect of the slenderness ratio (L/D) was also considered in this study (i.e. L/D= 25 and 40). In addition, a variety of two-way cyclic lateral loading conditions were applied to model piles using a mechanical loading system. One hundred cycles were used in each test to represent environmental loading such as offshore structures. It was found that under combined vertical and cyclic lateral loads the lateral displacement of piles decreased with an increase in vertical load whereas it causes large vertical displacements at all slenderness ratios. In addition, for all loading conditions the lateral, vertical (settlement and upward) displacements and bending moments increased as either the magnitude of cyclic load or the number of cycles increases.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Effect Of Number Of Cycles Of Loading On Load Lateral Displamentioning

confidence: 99%

Lateral Response of a Single Pile under Combined Axial and Lateral Cyclic Loading in Sandy Soil

Kahribt

Abbas

2018

CivileJournal

View full text Add to dashboard Cite

show abstract

“…In der Literatur sind Ergebnisse von unterschiedlichen Modellversuchen zu finden, die zur Untersuchung des Verhaltens von Monopilegründun-gen geeignet sind (Adams und Radhakrishna [3], Saglamer und Parry [20], Hettler [11], Abendroth und Greimann [1], Achmus et al [2], Kluge [15], Dührkop und Grabe [8], Cuéllar et al [7], LeBlanc et al [16]). …”

Section: Fachthemenunclassified

“…Im Bild 11 sind die im Versuch 4 in einem Abstand von 10 cm zum Pfahlmantel gemessenen und auf den Die Ergebnisse bestätigen das in Cuéllar et al [7] beschriebene Phäno-men großer Bodenbewegungen undumlagerungen an der Oberfläche im Pfahlnahbereich in der Belastungsrichtung, hervorgerufen durch die zyklische Horizontalbelastung des Pfahls. Dieses Phänomen konnte ansatzweise auch durch die eigenen Versuche be-Verdichtungseffekte zurückzuführen ist.…”

Section: Horizontale Bodenverschiebungenunclassified

Experimentelle Untersuchungen zum Verhalten von zyklisch horizontal belasteten Monopiles

num

Rackwitz³

et al. 2011

Bautechnik

View full text Add to dashboard Cite

Bei Monopilegründungen von Offshore‐Windenergieanlagen (OWEA) stellt die Prognose der akkumulierten Verschiebungen infolge zyklisch horizontaler Belastungen eine besondere Herausforderung dar. Eine zuverlässige Prognose erfordert gesicherte Erkenntnisse über das Verhalten von Boden‐Monopile‐Systemen unter zyklischen Belastungen. Hierzu wurde in der Geotechnischen Versuchsgrube der TU Berlin eine Versuchsreihe zur Untersuchung des Tragverhaltens von kurzen, mittellangen und langen Monopiles durchgeführt. Dabei wurden die Monopiles nach der Instrumentierung in wassergesättigten Sand eingepresst und anschließend durch zyklische Horizontalkräfte mit variierenden Belastungsamplituden und gleichzeitig wirkender statischer Vertikallast beansprucht. Während des Pfahleinpressvorganges wurden die maximalen Kräfte, die zum Einpressen der Versuchspfähle bis zur Solltiefe erforderlich waren, gemessen, und es wurde die Pfropfenbildung im Pfahlinneren festgestellt. In den Versuchen wurden horizontale und vertikale Pfahlverschiebungen an den Lasteinwirkungsstellen, Pfahlbiegedehnungen, horizontale Bodenverschiebungen neben dem Pfahl, Porenwasserdrücke im Boden sowie die Ausbreitung der Setzungsmulde an der Bodenoberfläche gemessen. Im Beitrag werden Konzeption, Vorbereitung und Durchführung dieser Pfahlversuche beschrieben sowie ausgewählte Ergebnisse vorgestellt und die aus den Untersuchungen gewonnenen Erkenntnisse zusammengefasst. Experimental investigations of cyclic laterally loaded monopiles. The prediction of accumulated deformations due to cyclic loading with monopile foundations of offshore wind power plants is a real challenge. Adequate predictions require profound knowledge about soil‐monopile interaction behaviour due to cyclic lateral loading. A number of monopile tests are performed in the geotechnical testing pit at TU Berlin in order to investigate that interaction behaviour in more detail. Short, intermediate and long open ended steel pipe piles have been jacked into water saturated sand after instrumentation and subsequently subjected to cyclic lateral loading with varying load amplitude and simultaneously acting static vertical load. Final vertical jacking pressure and sand plugging inside the pile were measured during pile installation. Pile head displacements, pile deformations, horizontal soil displacements close to the pile shaft, pore pressures as well as settlement of the soil surface were measured during the pile load tests. The paper presents concept, preparation and execution of the pile tests and illustrates main results as well as findings from these tests.

show abstract

“…Offshore wind turbines (OWTs) are relatively new structures with no long term track record of their performance yet they are to be constructed and meant to produce energy for 25-30 years [1][2][3][4]. OWTs, due to their slender nature coupled with irregular mass and stiffness distribution, are dynamically sensitive structures.…”

mentioning

confidence: 99%

Long-term dynamic behavior of monopile supported offshore wind turbines in sand

Wang

Guo

et al. 2015

Theoretical and Applied Mechanics Letters

View full text Add to dashboard Cite

The complexity of the loads acting on the offshore wind turbines (OWTs) structures and the significance of investigation on structure dynamics are explained. Test results obtained from a scaled wind turbine model are also summarized. The model is supported on monopile, subjected to different types of dynamic loading using an innovative out of balance mass system to apply cyclic/dynamic loads. The test results show the natural frequency of the wind turbine structure increases with the number of cycles, but with a reduced rate of increase with the accumulation of soil strain level. The change is found to be dependent on the shear strain level in the soil next to the pile which matches with the expectations from the element tests of the soil. The test results were plotted in a non-dimensional manner in order to be scaled to predict the prototype consequences using element tests of a soil using resonant column apparatus

show abstract

Ratcheting convective cells of sand grains around offshore piles under cyclic lateral loads

Cited by 53 publications

References 23 publications

Lateral Response of a Single Pile under Combined Axial and Lateral Cyclic Loading in Sandy Soil

Lateral Response of a Single Pile under Combined Axial and Lateral Cyclic Loading in Sandy Soil

Experimentelle Untersuchungen zum Verhalten von zyklisch horizontal belasteten Monopiles

Long-term dynamic behavior of monopile supported offshore wind turbines in sand

Contact Info

Product

Resources

About