Abstract
A common practice in mountainous areas for rockfall protection is to cover the top slab of a rockfall shed with a thick granular layer to buffer the impact. However, the weight of the sand is significant, with limited buffering capacity. This paper proposes a novel composite cushion consisting of a flexible buffer and a sand layer. Full-scale rockfall impact tests of 500 kJ were conducted to evaluate the performance of the cushion. Based on the sand layer impact test, DEM parameters for simulating sand were calibrated, and a numerical model of the composite cushion with rockfall impact using FEM-DEM coupling method was constructed. The buffering performance of the composite cushion was compared with the EPS-sand cushion. The study further investigates the effect of buffer height, sand layer thickness, and rockfall mass on impact force and energy distribution using numerical simulations. The results show that (1) the impact force on the composite cushion decreases by 73.2% compared to the sand layer. (2) The buffering performance of the composite cushion is equivalent to that of the 1 m EPS + 0.4 m sand cushion in terms of inhibiting the stress development on the shed slab. (3) The superior buffering performance of the cushion is attributed to the high flexibility of the net and the force-controlling characteristics of the energy dissipaters. Meanwhile, the sand layer plays more of a secondary defense role to prevent direct collision between the rockfall and the shed slab. These findings provide theoretical bases for the engineering design of such composite cushions.
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Acknowledgements
We would like to express our sincere gratitude to our former graduate classmate Zou Peng for his support during the experiments, as well as his supervisor Xu Hu for his selfless guidance in this work. The authors are grateful for the support provided by the Key Research and Development Program of Sichuan Province (Grant No. 2022YFG0414), the Key Science and Technology Projects in the Transportation Industry in 2020 (Grant No. 2020-MS3-101).
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YJ: conceptualization, project administration, methodology, software, validation, writing—review and editing. ZY: conceptualization, resources, project administration, funding acquisition. LL: formal analysis, investigation, data curation. LZ: writing—original draft, visualization. LL: supervision.
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Jin, Y., Yu, Z., Liao, L. et al. The buffering performance of a flexible buffer-sand layer composite cushion used for rockfall shed: experimental and numerical investigation. Landslides 21, 1003–1022 (2024). https://doi.org/10.1007/s10346-023-02196-3
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DOI: https://doi.org/10.1007/s10346-023-02196-3