To evaluate the beneficial effect of rubber bearings on the seismic performance of underground station structures, three-dimensional finite element models of seismic soil-structural systems are established for a single-layer double span subway station. The seismic mitigation effect is investigated by employing the pushover analysis method. The obtained results indicated that the installation of rubber bearings can effectively alleviate stress concentration and damage degree of the central column, especially at its end area. Compared with the conventional column, the elastic and elastoplastic deformation capacity of the column fitted with rubber bearings both improved significantly. It was also found that the load bearing and deformation performance decrease with the increase of the axial pressure ratio. Furthermore, the lateral force distribution mechanism of the structural system fitted with the rubber bearings is significantly different from the original structure; the deformation and internal forces of central column of the seismic mitigation structure decreased substantially, but side walls' deformation and internal forces increased slightly. The proportion of shear force taken by the central column has decreased, while the side walls have taken larger share, i.e., the rubber bearings facilitated the transfer of seismic forces from the middle column to the side wall.

With increasing water depth, marine drilling conductors exhibit higher slenderness ratios, significantly reducing their resistance to environmental loads in Arctic waters. These conductors, when subjected to combined wind, current, and ice loads, may experience substantial horizontal displacements and bending moments, potentially compromising offshore operational safety and wellhead stability. Additionally, soil disturbance near the mudline diminishes the conductor's bearing capacity, potentially rendering it inadequate for wellhead support and increasing operational risks. This study introduces a static analysis model based on plastic hinge theory to evaluate conductor survivability. The conductor analysis divides the structure into three segments: above waterline, submerged, and embedded below mudline. An idealized elastic-plastic p-y curve model characterizes soil behavior beneath the mudline, while the finite difference method (FDM) analyzes the conductor's mechanical response under complex pile-head boundary conditions. Numerical simulations using ABAQUS validate the plastic hinge approach against conventional methods, confirming its accuracy in predicting structural performance. These results provide valuable insights for optimizing installation depths and bearing capacity designs of marine drilling conductors in ice-prone regions.

This study investigated the failure phenomenon of steel plate-reinforced concrete shaft structures situated in soil under medium-field explosions. Through model experiments and finite element numerical simulations, we analyzed the process of plastic hinge line formation and the deformation characteristics of the structure, and the dimensionless circumferential relative displacement alpha 1 was proposed as an index to measure the structural deformation. According to the damage characteristics, the structural failure modes were divided into standard failure mode and three extension failure mode. The empirical formula of the characteristic size of plastic hinge line is derived from the numerical simulation data. Based on the numerical simulation data and the law of conservation of energy, the empirical formula of the characteristic size of the plastic hinge line was obtained by fitting, the motion field of each plate in the plastic hinge line was analyzed, and the calculation method of the rigid plastic deformation of the shaft structure was established. We compared the discrepancies between the finite element calculation model and the theoretical algorithm and examined the impacts of concrete strength, concrete thickness to radius ratio, steel plate thickness to radius ratio, and charge mass on steel plate displacement. The results showed that increasing concrete strength and the thicknesses of both concrete and steel plates improved the structure's blast resistance and reduced deformation. And at the same scaled explosive distance, a higher charge mass increased the distance to the structure, leading to greater external work and structural deformation. In cases where concrete thickness to radius ratio greater than 13%, the relative error between theoretical calculations and numerical simulations was below 20%, indicating the computational method's accuracy in predicting the deformation of steel plate-reinforced concrete shaft under medium-field explosions.