The existing studies have primarily focused on the effect of cyclic load characteristics(namely,cyclic load ratio and amplitude ratio)on cyclic lateral response of monopiles in sand,with little attention paid to the effect of pile-soil relative stiffness(KR).This paper presents a series of 1-g cyclic tests aimed at improving understanding of the cyclic lateral responses of monopiles under different pile-soil systems.These systems are arranged by two model piles with different stiffness,including four different slenderness ratios(pile embedded length,L,normalized by diameter,D)under medium dense sand.The KR-values are calculated by a previously proposed method considering the real soil stress level.The test results show that the lateral accumulation displacement increases significantly with the increment of the KR-value,while the cyclic secant stiffness performs inversely.The maximum pile bending moment increases with the cycle number for the rigid pile-soil system,but shows a decreasing trend in the flexible system.For an uppermost concern,an empirical model is proposed to predict the accumulated displacement of arbitrary pile-soil systems by combining the results from this study with those from previous experimental investigations.The validity of the proposed model is demonstrated by 1-g and centrifuge tests.

Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education,Southeast University,Nanjing 211189,China;School of Civil Engineering,Southeast University,Nanjing 211189,China;School of Civil Engineering and Architecture,Jiangsu University of Science and Technology,Zhenjiang 212003,China;Department of Built and Environment Engineering,The University of Newcastle,Callaghan,New South Wales,Australia

[1]WANG Yang;ZHU Ming-xing;GONG Wei-ming;DAI Guo-liang;WU Jin-biao;ZHU Wen-bo-.Cyclic Lateral Responses of Monopiles Considering the Influence of Pile-Soil Relative Stiffness in Sand)[J].中国海洋工程（英文版）,2022(02):247-257

Monopiles,monopiles,secant

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