The effect of cyclic loading is an essential factor leading to progressive soil strength degradation. Therefore, a comprehensive analysis of the pile-soil system behavior under cyclic loading is required to ensure the stability of pile group. There is room for improvement in the inherent constraint of the conventional numerical model in terms of approximating the soil resistance distribution along the pile by point loads at element nodes, necessitating a specific element that integrates considerations of pile group effect and cyclic loading within a unified framework. This study aims to develop a newly specific type of element for efficiently predicting nonlinear behavior within the pile-soil system, addressing simulations involving nonlinear pile-soil interaction, pile group effect, and cyclic loading. Modified element formulations based on soil stiffness matrices and soil resistance vectors specifically address pile group effect and consider parameters that influence pile behavior under cyclic lateral loading. The numerical solution procedure with Newton-Raphson iteration allows the calculation of pile responses in geometric and material nonlinear analyses. The validation of the proposed method includes several examples, comparing it with existing numerical solutions and experimental tests of single piles and pile groups under cyclic loading. These comparisons further support the consistency of the proposed method with measured data and validate its accuracy in considering group effect and cyclic loading. The parametric study illustrates the ability of the proposed method to capture cyclic loading parameters while considering the influence of the number and magnitude of load cycles, the cyclic load direction, and the installation methods.

Liquid storage tanks are often arranged in rows with small spacing in practical applications, which may cause mutual influence under earthquake action and even aggravate the seismic damage of liquid storage tanks. Adding the vibration barrier (ViBa) into the foundation between the adjacent liquid storage tanks forms a new type of seismic control method. Considering important factors such as liquid-solid-soil coupling, liquid sloshing behavior, and structure-soil-structure interaction (SSSI), a refined 3D numerical calculation model of the adjacent liquid storage tanks with three ViBas is established by ADINA. The influence of seismic wave incidence angle on the seismic responses of the liquid storage tanks and the control effect of ViBa are studied, and the parameter influence analysis is carried out. The results show that the ViBa significantly control the seismic responses and liquid sloshing wave height of the adjacent liquid storage tanks, and the damping ratio of the liquid sloshing wave height is between 30% and 40%. When the seismic incidence angle is between 30(degrees) and 60(degrees), the dynamic responses of the liquid storage tank is larger. With the increase of the seismic incidence angle, the control effect of the ViBa on the effective stress, hoop stress, axial compressive stress, and liquid pressure first increases and then decreases. When the liquid storage tank is close to full state, the control effect is most significant at an incidence angle of 60(degrees), and the control effect of the ViBa on the liquid storage tank with medium height-diameter ratio is the best.