In the heart of China’s coastal city of Xiamen, researchers from Xiamen University’s Department of Civil Engineering are making waves in the field of earthquake engineering. Their recent study, published in *Yantu gongcheng xuebao* (translated to *Rock and Soil Engineering*), delves into the seismic performance and risk assessment of sheet-pile retaining walls subjected to liquefaction, a phenomenon that poses significant threats to waterfront structures during earthquakes.
Lead author QIU Zhijian and his team, including ZHANG Yuxin and GU Quan, have developed a novel approach to simulate the liquefaction characteristics of saturated sandy soils. “We employed a multi-yield surface elasto-plastic constitutive model that systematically considers the dynamic coupling effect between pore water and soil particles,” QIU explains. This advanced modeling technique allows for a more accurate prediction of how earthquakes trigger liquefaction and subsequently impact retaining walls.
The team’s research is particularly relevant to the energy sector, where waterfront infrastructure is crucial for operations such as oil and gas terminals, LNG facilities, and renewable energy projects. Understanding the seismic risks associated with liquefaction can help mitigate potential damages and ensure the safety and continuity of these critical facilities.
To validate their model, the researchers conducted a series of centrifuge tests and compared the results with real-world data. “We selected 100 ground motion records to develop seismic fragility curves and seismic risk curves for the sheet-pile retaining wall model,” says QIU. This extensive dataset enabled the team to identify the Cumulative Absolute Velocity (CAV) as the optimal seismic intensity parameter, providing a more practical and effective tool for assessing seismic risks.
One of the key findings of the study is the influence of soil permeability on the seismic performance of sheet-pile retaining walls. “Our analysis shows that soil permeability plays a significant role in determining the extent of liquefaction-induced lateral spreading and, consequently, the overall seismic risk,” QIU notes. This insight can help engineers design more resilient structures and implement targeted mitigation measures in liquefiable sites.
The implications of this research extend beyond the immediate findings. As ZHANG Yuxin points out, “Our study provides a foundation for developing more advanced constitutive models and numerical methods to better understand and predict the behavior of retaining structures under seismic loading.” This, in turn, can lead to improved design codes and guidelines for waterfront infrastructure, ultimately enhancing the safety and reliability of energy sector facilities.
In the ever-evolving landscape of earthquake engineering, QIU, ZHANG, and GU’s work serves as a testament to the power of innovative research in addressing real-world challenges. Their study not only advances our understanding of liquefaction-induced risks but also paves the way for more robust and resilient waterfront structures, ensuring the continued growth and stability of the energy sector in seismic-prone regions.