Integral abutment bridges (IABs) provide a viable solution to address durability concerns associated with bearings and expansion joints. Yet, they present challenges in optimizing pile foundation design, particularly concerning horizontal stiffness. While previous studies have focused on the behaviour of various piles supporting IABs in non-liquefied soils under cyclic loading, research on their seismic performance in liquefied soils remains limited. This study addresses the gap by systematically comparing the performance of various pile foundations in liquefied soil, focusing on buckling mechanisms and hinge formation. Using the Pyliq1 material model and zero-length elements in OpenSees, soil liquefaction around the piles was simulated, with numerical results validated against experimental centrifuge tests. The findings indicate that IABs supported by reinforced concrete piles with a 0.8 m diameter (RCC8) experience greater displacement at the abutment top, while alternative piles, such as 0.5 m (RCC5), HP piles with weak and strong axis (HPS and HPW), steel pipes (HSST) and concrete-filled steel tubes (CFST), show pronounced rotational displacement at the abutment bottom. Maximum stress, strain and bending moments occurred at the pile tops and at the interface between liquefied and non-liquefied soil. Notably, CFST piles resisted buckling under seismic excitation, suggesting their superiority for supporting IABs in liquefied soil.

Liquefaction is a catastrophic phenomenon that poses a serious threat to lifelines during an earthquake. To assess the seismic behaviour of a well casing buried in saturated sand, a series of 1-g shaking table model tests were performed. The present study aims to investigate the impacts of the relative density and groundwater level on the base case as well. The responses of the models, including accelerations, pore water pressure changes, settlements, and strains induced along the well casing at various locations, were measured during the shaking. The outcomes illustrated that the groundwater level has a significant effect on the position of maximum strain. A rise in relative density leads to a 40.7% reduction in strains and moments caused along the well casing, while the rate of strain permanence in denser soils is considerable compared to looser soils. Moreover, experimental results indicated that the maximum shear force caused at the bottom of the well casing grows about 67% with increasing groundwater table.

Building with rammed earth has become increasingly popular in recent years because it is highly sustainable and has little environmental impact. More than half of the world's population lives in earthen houses, many of which are located in earthquake-prone areas such as Croatia. However, their seismic performance still needs to be researched, especially considering local construction techniques. One of the first steps in this process is the experimental testing of such walls. Four models of rammed earth walls were constructed using traditional local building techniques and experimentally tested under in-plane cyclic loading to investigate their seismic behaviour. The model walls were built using locally available soil material. The new particle size distribution envelope for determining the suitability of soil material for rammed earth construction was proposed for the first time. The building material was chosen according to the envelope. Moreover, walls were made using two different material compositions-i.e., natural soil from eastern Croatia and man-made soil with the addition of fine gravel. The main objective, the seismic performance of the RE walls, was evaluated in terms of their bearing capacity, behaviour after yielding, failure mode, stiffness degradation, initial elastic stiffness, and energy dissipation capacity.