TY - GEN

T1 - Model tests on the behaviour of monopiles under general cyclic lateral loading

AU - Frick, Dennis

AU - Achmus, Martin

N1 - Funding information: This study was carried out in scope of the research project “Accumulation of lateral displacements of piles under general cyclic one-and two-way loading” (project no. 393683178) funded by German Research Foundation (DFG). The authors sincerely acknowledge DFG support.

PY - 2019/6

Y1 - 2019/6

N2 - A crucial aspect in the design of large diameter monopile foundations for offshore wind energy converters is the load-deflection behaviour of such structures mainly subjected to long-term lateral cyclic loading. Cyclic loading leads to an accumulation of permanent deflections and rotations of the monopile, which have to be limited in order to fulfil serviceability criteria. Predictions of deflection accumulation rates are rather unreliable. In particular, the effect of general two-way loading on the accumulation rate needs further investigation. This paper presents a brief overview on existing methods for the prediction of accumulated deflections or rotations of monopiles. Then, a new small-scale 1-g testing facility especially designed for the evaluation of the pile response due to long-term cyclic loading under arbitrary loading conditions is described. Both monotonic tests (for the determination of the ultimate pile capacity) and cyclic tests with varying loading types and load conditions have been conducted. The results of these tests are presented and discussed. The cyclic test results are used to identify the parameters of a correction function for the displacement accumulation rate, which accounts for the type of cyclic loading applied.

AB - A crucial aspect in the design of large diameter monopile foundations for offshore wind energy converters is the load-deflection behaviour of such structures mainly subjected to long-term lateral cyclic loading. Cyclic loading leads to an accumulation of permanent deflections and rotations of the monopile, which have to be limited in order to fulfil serviceability criteria. Predictions of deflection accumulation rates are rather unreliable. In particular, the effect of general two-way loading on the accumulation rate needs further investigation. This paper presents a brief overview on existing methods for the prediction of accumulated deflections or rotations of monopiles. Then, a new small-scale 1-g testing facility especially designed for the evaluation of the pile response due to long-term cyclic loading under arbitrary loading conditions is described. Both monotonic tests (for the determination of the ultimate pile capacity) and cyclic tests with varying loading types and load conditions have been conducted. The results of these tests are presented and discussed. The cyclic test results are used to identify the parameters of a correction function for the displacement accumulation rate, which accounts for the type of cyclic loading applied.

KW - Cyclic loading

KW - Displacement accumulation

KW - Model tests

KW - Monopile

UR - http://www.scopus.com/inward/record.url?scp=85099099347&partnerID=8YFLogxK

M3 - Conference contribution

T3 - International Conference on Natural Hazards & Infrastructure

BT - International Conference on Natural Hazards & Infrastructure

T2 - 2nd International Conference on Natural Hazards & Infrastructure

Y2 - 23 June 2019 through 26 June 2019

ER -