TY - JOUR

T1 - Capacity degradation method for piles under cyclic axial loads

AU - Achmus, M.

AU - Kuo, Y. S.

AU - Abdel-Rahman, K.

AU - Tseng, Y. H.

AU - Pang, I.

PY - 2020/12

Y1 - 2020/12

N2 - Piles used for jacket type foundation of offshore wind turbine are subjected to highly cyclic tension and compressive loading. The pile capacity under cyclic tension loading decreases with increased number of loading cycles due to reduction of the pile shaft resistance. A numerical simulation scheme is presented, which allows the calculation of the pile capacity degradation (CDM) due to cyclic loading for driven steel piles. The volume compaction of soil near the pile surface during the cyclic loading is determined from the cyclic simple shear test results and then applied to the pile-soil system. From the limited number of tests available, interaction diagrams have been developed, which give the number of load cycles leading to failure dependent on the mean load and the amplitude of the cyclic load portion, which are both related to the static pile capacity. However, such diagrams cannot account for different soil conditions or pile geometry and pile stiffness. The calculation results for different piles in sandy soil under cyclic axial loading are presented and compared with existing interaction diagrams. Finally, recommendations regarding further investigations and improvements of the method are given.

AB - Piles used for jacket type foundation of offshore wind turbine are subjected to highly cyclic tension and compressive loading. The pile capacity under cyclic tension loading decreases with increased number of loading cycles due to reduction of the pile shaft resistance. A numerical simulation scheme is presented, which allows the calculation of the pile capacity degradation (CDM) due to cyclic loading for driven steel piles. The volume compaction of soil near the pile surface during the cyclic loading is determined from the cyclic simple shear test results and then applied to the pile-soil system. From the limited number of tests available, interaction diagrams have been developed, which give the number of load cycles leading to failure dependent on the mean load and the amplitude of the cyclic load portion, which are both related to the static pile capacity. However, such diagrams cannot account for different soil conditions or pile geometry and pile stiffness. The calculation results for different piles in sandy soil under cyclic axial loading are presented and compared with existing interaction diagrams. Finally, recommendations regarding further investigations and improvements of the method are given.

KW - Capacity degradation

KW - Cyclic axial loading

KW - Interaction diagrams

KW - Offshore

KW - Piles

UR - http://www.scopus.com/inward/record.url?scp=85091974720&partnerID=8YFLogxK

U2 - 10.1016/j.compgeo.2020.103838

DO - 10.1016/j.compgeo.2020.103838

M3 - Article

AN - SCOPUS:85091974720

VL - 128

JO - Computers and Geotechnics

JF - Computers and Geotechnics

SN - 0266-352X

M1 - 103838

ER -