Geosynthetics have increasingly been used in geotechnical engineering applications due to their numerous benefits, including the cost-effectiveness, reliability and contribution to sustainability. When employed in transport infrastructure projects, geosynthetics may perform a variety of functions, leading to increased stability and longevity of the system. This paper describes a laboratory study carried out using a large-scale direct shear test apparatus to characterise the direct shear behaviour of the interfaces between a recycled construction and demolition (C&D) material and two geosynthetics (a geogrid and a geocomposite) subjected to cyclic normal loading. The direct shear tests were performed under a constant shear displacement rate, while the normal loading varied cyclically at predefined frequency and amplitude values. Direct shear tests under static normal loading were also performed for comparison purposes. Test results have shown that the interface shear strength and dilation behaviour tend to decrease under cyclic normal loading and are influenced by the applied frequency and amplitude. The peak and large displacement shear strengths of the interface with the geogrid exceeded those reached when the geocomposite was used, which may be attributed to more effective interlocking of the aggregates within the geogrid apertures.

This study assesses the seismic fragility curves of in-service piled bridge abutments on liquefaction-prone soils and evaluates an optimal countermeasure within the vulnerability framework. Seismic fragility curves, accounting for varying ground motion intensities, assess the seismic risk and describe abutment damage through settlement measurements. The ageing abutment performance is estimated by integrating a corrosion model into fragility curves. The impact of different sheet pile positions on the seismic performance of in-service piled bridge abutments is analysed, and the optimal pile position is discussed. The developed fragility curves provide a rapid and effective risk assessment tool for the seismic performance of in-service abutments and guide liquefaction remedial measures.

In this study, the seismic resilience of granular column-supported road embankments on liquefiable soils is examined to enhance the understanding and seismic design of resilient transportation infrastructure. A nonlinear dynamic analysis of embankments on liquefiable soils is performed, and the results are validated against centrifuge test data. In the assessment, a functional analysis framework encompassing fragility, vulnerability, and restoration functions is employed to evaluate the robustness and recovery of embankments. The resilience of embankments is quantified by the comprehensive life-cycle resilience index (R), which considers various factors, such as the embankment height, the liquefiable soil thickness, and the area replacement ratio (AR) of granular columns. A simplified design method is proposed that involves a model for rapidly assessing the resilience state of embankments under varying seismic intensities. The analysis highlights the essential role of granular columns in mitigating liquefaction-induced damage during seismic events, improving robustness, and recovering postearthquake functionality, and a practical and reliable tool is developed for assessing embankment resilience across diverse seismic scenarios.