Seismic Hazard Assessment of Power Plant Structures Founded on Block-Type Deep Soil Mixing–Improved Ground Considering Soil–Structure Interaction

Yaghfoori, Ali; Mahmoudzadeh Kani, Iradj; Yousefi, Hassan

doi:10.22111/jneh.2026.54873.2160

Seismic Hazard Assessment of Power Plant Structures Founded on Block-Type Deep Soil Mixing–Improved Ground Considering Soil–Structure Interaction

Articles in Press

Document Type : Research Article

Authors

¹ PhD student of Earthquake Engineering, School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran

² Professor, School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran

³ Assistant Professor, School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran

10.22111/jneh.2026.54873.2160

Abstract

Earthquakes are among the most significant natural hazards that threaten the safety of critical and sensitive structures, such as nuclear power plants, and can disrupt energy production, leading to irreversible environmental and human consequences. International standards and IAEA guidelines emphasize that the seismic design of nuclear facilities must protect human life and the environment. For heavy, sensitive infrastructure, Deep Soil Mixing (DSM) is recommended to mitigate seismic hazards; this study evaluates its effectiveness in reducing seismic risk for an operational nuclear reactor. The APR1400 reactor was modeled on a multi-layered soil improved by DSM based on laboratory test results. The soil-structure interaction (SSI) and structure-soil-structure interaction (SSSI) were analyzed under unidirectional Ricker wave loading at various frequencies, as well as under unidirectional and bidirectional near-field earthquake records. The results indicated that horizontal acceleration was higher in the internal structure than in the containment building and decreased with increasing excitation frequency; DSM implementation beneath the foundation increased horizontal acceleration, with a more pronounced effect in the internal structure. Analysis of vertical acceleration revealed that the containment building, due to its location at the edge of the foundation, experienced higher vertical acceleration, and DSM-enhanced rocking motion further increased it. The effect of DSM on the internal structure was frequency-dependent. Bidirectional loading had a negligible impact on horizontal acceleration but significantly increased the Fourier amplitude and energy of vertical acceleration. Overall, SSSI reduced horizontal acceleration, but the presence of a second structure at 50 m locally reduced horizontal acceleration while increasing vertical acceleration. These findings highlight the importance of 3D modeling, application of near-field seismic records, and careful consideration of SSSI and inter-structure spacing for mitigating seismic hazards, protecting human life and the environment, and designing safe nuclear facilities with sensitive equipment and high-frequency content.

Keywords

Main Subjects

Environmental Science & Engineering

References

References (in English)

Hasegawa, K. (2012). Facing nuclear risks: Lessons from the Fukushima nuclear disaster. International Journal of Japanese Sociology, 21(1), 84-91.https://doi.org/10.1111/j.1475-6781.2012.01164.x

Jeremić, B., Jie, G., Preisig, M., & Tafazzoli, N. (2009). Time domain simulation of soil–foundation–structure interaction in non‐uniform soils. Earthquake Engineering & Structural Dynamics, 38(5), 699-718. https://doi.org/10.1002/eqe.896

Kanellopoulos, C., Rangelow, P., Jeremic, B., Anastasopoulos, I., & Stojadinovic, B. (2024). Dynamic structure-soil-structure interaction for nuclear power plants. Soil dynamics and earthquake engineering, 181, 108631. https://doi.org/https://doi.org/10.1016/j.soildyn.2024.108631

Wada, T., Nemoto, Y., Shimamura, S., Fujita, T., Mizuno, T., Sohtome, T., Kamiyama, K., Morita, T., & Igarashi, S. (2013). Effects of the nuclear disaster on marine products in Fukushima. Journal of Environmental Radioactivity, 124, 246-254. https://doi.org/https://doi.org/10.1016/j.jenvrad.2013.05.008

Yaghfoori, A., Mahmoudzadeh Kani, I., & Yousefi, H. (2025a). Seismic behavior of dry sandy soils improved with Block-Type Deep Soil Mixing in near-fault regions. AUT Journal of Civil Engineering. 10.22060/ajce. 2025.24157.5923

Yaghfoori, A., Mahmoudzadeh Kani, I., & Yousefi, H. (2025b). Seismic performance and optimization of deep soil mixing (DSM) for response mitigation at power plant sites. Engineering Computations, 41(8), 1-42. https://doi.org/10.1108/EC-05-2025-0508.