Penetration Resistance of Skirt-Tip with Rough Base for Suction Caissons in Clay

作     者：WU Yu-qi LI Da-yong YANG Qing WU Yu-qi;LI Da-yong;YANG Qing

作者机构：State Key Laboratory of Coastal and Offshore EngineeringDalian University of TechnologyDalian 116024China College of Civil EngineeringFuzhou UniversityFuzhou 350108China College of Civil Engineering and ArchitectureShandong University of Science and TechnologyQingdao 266590China 

出 版 物：《China Ocean Engineering》 (中国海洋工程（英文版）)

年 卷 期：2020年第34卷第6期

页      面：784-794页

核心收录：

学科分类：081505[工学-港口、海岸及近海工程] 0908[农学-水产] 08[工学] 0710[理学-生物学] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 0707[理学-海洋科学] 0807[工学-动力工程及工程热物理] 0815[工学-水利工程] 0824[工学-船舶与海洋工程] 0802[工学-机械工程] 0814[工学-土木工程] 082401[工学-船舶与海洋结构物设计制造] 0801[工学-力学（可授工学、理学学位）] 

基　　金：financially supported by the National Natural Science Foundation of China (Grant Nos. 51639002 and 51879044) the SDUST Research Fund (Grant No. 2015KYJH104) 

主　　题：suction caisson required suction pressure penetration resistance skirt-tip rough base clay 

摘      要：Suction caissons can readily penetrate into the seabed under the combination of the self-weight and suction resulted from the encased water being increasingly pumped out. During suction-assisted penetration, the equivalent overburden at the skirt-tip level outside the caisson is generally higher than that inside because the vertical stress within the soil plug is reduced by the exerted suction. This may result in a uniform shear stress developing over the base of the skirt-tip as the soil below the skirt-tip tends to move into the caisson, which leads to an asymmetric failure wedge existing below the base of the skirt-tip. Besides, different adhesion factors along the inside(αi) and outside(αo) of the skirt wall will cause asymmetric plastic zones inside and outside the caisson. Accordingly, an asymmetric failure mechanism is therefore proposed to calculate the penetration resistance of the skirt-tip. The proposed failure mechanism is the first to consider the effect of different adhesion factors(αi) and(αo) on the failure mechanism at the skirt-tip, and involves the contribution from the weighted average of equivalent overburdens inside and outside caisson at the skirt-tip level. The required suction pressure can be obtained in terms of force equilibrium of the caisson in a vertical direction. Finally, the asymmetric failure mechanism at the skirt-tip is validated with the FE calculations. By comparing with the measured data, the predictions of the required suction pressure are found to be in good agreement with the experimental results.