In order to study the failure mechanism of a finned pile foundation under horizontal cyclic loads, a physical model test of the pile-soil interaction of finned pile is designed in this paper. Based on the model tests, the pile top displacement, the cyclic stiffness of the pile foundation, and the response of pore water pressure within the soil around the pile were fully studied for the finned pile foundation under horizontal cyclic loads. It is found that the cyclic stiffness attenuation of the finned pile foundation is more severe than that of a regular single pile foundation, but the final stiffness at equilibrium is still greater than that of a regular single pile foundation. The accumulation of horizontal displacement at the pile top and pore water pressure within the soil around the pile mainly occurs in the first 1000 loading cycles, and an increase in fin plate size will reduce the magnitude of pore water pressure and pile top displacement. This study can not only deepen the understanding of the failure mechanism of finned pile foundation under horizontal cyclic loads, but also provide guidance for the design of the finned pile foundation.

Long-span river or sea crossing bridge projects are commonly subjected to significant and complex long-term cyclic loads driven by factors such as wind and waves. The lattice-shaped diaphragm wall (LSDW) foundation, a novel and promising solution for long-span bridges, offers advantages in construction safety, adaptability, costeffectiveness, and stiffness. However, research in this area remains limited, impeding the further application of LSDWs. This study comprehensively investigates the bearing behavior of LSDWs under horizontal cyclic loads in soft soils. It introduces a detailed methodology utilizing a dual-layer wall setup and mathematical calculations to measure key parameters such as wall bending moments, displacements, and soil pressures. The research explores LSDW behavior throughout cyclic loading cycles, revealing trends in soil compression, densification, and displacement growth rates. Analysis of cumulative displacement and rotation patterns underscores the influence of load amplitudes and wall stiffness. The findings highlight the significant impact of cyclic loading cycles on cumulative displacement, with curve fitting revealing a logarithmic function with a strong correlation. Additionally, the study delves into the reduction in lateral soil resistance with increasing cyclic loads, proposing cyclic weakening factors for predicting soil pressure distribution and cyclic p-y curves. This study offers valuable insights into the comprehensive analysis and prediction of the performance of LSDW subjected to horizontal cyclic loading, with potential implications for long-span bridge construction projects.