Assessing structural foundation damage following an earthquake is critical for safety evaluation. However, assessing the damage to pile foundations with traditional visual inspections and non-destructive testing methods is challenging. This study evaluated the use of acoustic emission (AE) monitoring for damage detection and location in foundation structures during earthquake simulations by conducting shaking table experiments. Scaled models of foundation structures with and without surrounding soil were used in the experiments, and the performance of the AE monitoring system was evaluated by comparing the AE parameters via visual inspection. The experimental results showed that the AE monitoring system could effectively predict the initiation of cracks in foundation structures that experienced an earthquake. In addition, an appropriate filtering criterion for the shaking table experiments was established based on the AE characteristics of the foundation structures during the earthquake simulation, thereby improving the performance of the AE monitoring system for damage location. Consequently, this study contributed to a better understanding of the applicability of AE monitoring systems to foundation structures during earthquakes. (c) 2024 Production and hosting by Elsevier B.V. on behalf of The Japanese Geotechnical Society. This is an open access article under the CC BY- NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

This study investigates the behavior of suction bucket foundations during seismic loading induced soil liquefaction through shaking table experiments using both steel and 3D printed mini buckets. The pore water pressure response of the soil inside and around the mini buckets was monitored, and the results show that excess pore water pressure ratios greater than 1.0, indicating liquefaction occurred inside and around the buckets. In order to verify whether the soil plug liquefies under seismic loading, a floating ball experiments was specifically designed. The findings suggest that behavior of suction bucket foundations may differ from that of gravity-based foundations when experiencing soil liquefaction, owing to their unique semi-enclosed geometric structure and suction installation method. The appropriately weighted steel mini bucket has the advantage of being less prone settlement in the liquefied soil, making it suitable as a monitoring platform for soil liquefaction.

Understanding the destabilization mechanisms in bedrock and overburden layer slopes influenced by both rainfall and seismic activity is of significant engineering importance. A series of large-scale shaking table model tests was conducted to investigate the instability evolution in bedrock and overburden layer slopes after rainfall and seismic events. This study identifies and assesses degradation modes based on spatial deformation characteristics and slope surface displacement patterns. It integrates soil stress-strain behavior, permeability characteristics, seismic stress distribution, and slope deformation characteristics to explore the deformation mechanisms in bedrock and overburden layer slopes after rainfall and seismic events. The results indicate: (1) During rainfall, saturation significantly increases at the slope crest and toe, leading to notable strength degradation without significant overall deformation. However, during seismic activity, the slope crest initially experiences sliding failure, evolving into multi-stage sliding instability. (2) Macroscopic damage occurs suddenly, and the spatial strain distribution within the slope better identifies the evolution of plastic zone expansion, penetration, and instability. (3) The slope's instability evolution pattern, analyzed by residual displacement ratios, aligns well with the spatial strain evolution within the soil, showing greater sensitivity in identifying the slope's damage state compared to cumulative displacement. (4) Changes in moisture content affect soil mechanical properties, and post-rainfall infiltration field distribution affects the slope's overall mechanical behavior and the transmission and spatial distribution of seismic stress. Soil mechanical properties and dynamic stress spatial characteristics determine the slope's failure modes.

The integrated building-bridge structure system represents integrated railway stations in China and has emerged as a new structural approach in recent years. This paper presents a case study on large shaking table tests that explore various seismic responses of a pile group system based on the Kunming South Railway Station. The study focused on the dynamic characteristics of both the soil and the pile-superstructure interaction. Findings indicate that pile damage is concentrated on the side facing the direction of vibration, with the middle pile experiencing greater damage than the corner pile. Hysteresis is observed in the growth of the pore pressure ratio during soil liquefaction in saturated conditions. Both the bending moment and the ground pressure acting on the pile increase with the degree of liquefaction. The maximum pile bending moment occurs at the interface between liquefied and non-liquefied soil layers. During seismic events, the side piles facing the vibration direction experience increased seismic surcharge, while the central piles are subjected to lower loads due to the isolation effect of the side piles.