In the realm of earthquake engineering, the classification of sites based on their geological characteristics is a critical step in determining the seismic design parameters for construction projects. A recent study published in *Yantu gongcheng xuebao* (translated to *Chinese Journal of Geotechnical Engineering*) has shed new light on the effectiveness of different site classification methods, with significant implications for the energy sector and other industries.
The research, led by LI Xiaojun of the National Key Laboratory of Bridge Safety and Resilience at Beijing University of Technology, along with colleagues CHENG Xiaofang, RONG Mianshui, and ZHANG Bin from the Institute of Earthquake Science at China Earthquake Administration, delves into the nuances of site classification methods. The study compares the one-index method, which relies solely on the equivalent shear wave velocity of rock and soil layers within a specified depth, and the two-index method, which considers both the shear wave velocity and the thickness of overlying soil layers.
The primary goal of site classification is to assess how a site will respond to strong ground motion, thereby informing the seismic design parameters for construction projects. The degree of consistency in the spectral characteristics of strong motion records within the same classified site is a key indicator of the method’s rationality.
Utilizing data from the Japanese strong-motion seismograph network KiK-net and related site borehole data, the researchers conducted a comprehensive statistical analysis. They classified observation stations using various site classification methods, including those specified in seismic design codes from China, the United States, and Japan, as well as several recently proposed methods. The collected strong motion records were then grouped accordingly.
“Our study reveals that the site classification method outlined in the Chinese seismic design code, a two-index method based on the equivalent shear wave velocity of soil layers and the thickness of overlying soil layers, stands out as the most effective,” said LI Xiaojun. This method demonstrated the highest consistency and clustering property of acceleration response spectra for strong motion records from observation stations with the same site class.
The implications of this research are profound, particularly for the energy sector. Accurate site classification is crucial for the design and construction of energy infrastructure, such as oil and gas facilities, power plants, and renewable energy installations. Ensuring that these structures can withstand seismic events is not only a matter of safety but also of economic viability.
The study’s findings suggest that adopting the two-index method could lead to more precise seismic design parameters, potentially reducing construction costs and enhancing the resilience of energy infrastructure. As the energy sector continues to expand and diversify, the need for robust and reliable site classification methods will only grow.
The research also underscores the importance of continuous refinement and validation of site classification methods. As LI Xiaojun noted, “The consistency and clustering property of acceleration response spectra are critical criteria for evaluating the rationality of site classification methods. Our study provides a framework for future research in this area.”
In conclusion, the study published in *Yantu gongcheng xuebao* offers valuable insights into the effectiveness of different site classification methods, with significant implications for the energy sector and other industries. By adopting the most effective methods, stakeholders can ensure the safety and economic viability of their projects, ultimately contributing to a more resilient and sustainable future.