ISSN 1003-8035 CN 11-2852/P
    陈宇,沈位刚,宋忠友,等. 基于离散元数值模拟的土垫层缓冲落石冲击力特性分析[J]. 中国地质灾害与防治学报,2023,35(0): 1-8. DOI: 10.16031/j.cnki.issn.1003-8035.202211020
    引用本文: 陈宇,沈位刚,宋忠友,等. 基于离散元数值模拟的土垫层缓冲落石冲击力特性分析[J]. 中国地质灾害与防治学报,2023,35(0): 1-8. DOI: 10.16031/j.cnki.issn.1003-8035.202211020
    CHEN Yu,SHEN Weigang,SONG Zhongyou,et al. Analysis of soil cushion buffering characteristic for rockfall impact force through discrete element numerical simulation[J]. The Chinese Journal of Geological Hazard and Control,2023,35(0): 1-8. DOI: 10.16031/j.cnki.issn.1003-8035.202211020
    Citation: CHEN Yu,SHEN Weigang,SONG Zhongyou,et al. Analysis of soil cushion buffering characteristic for rockfall impact force through discrete element numerical simulation[J]. The Chinese Journal of Geological Hazard and Control,2023,35(0): 1-8. DOI: 10.16031/j.cnki.issn.1003-8035.202211020

    基于离散元数值模拟的土垫层缓冲落石冲击力特性分析

    Analysis of soil cushion buffering characteristic for rockfall impact force through discrete element numerical simulation

    • 摘要: 棚洞是我国西部山区防治崩塌落石灾害的主要工程措施之一。棚洞顶板以上通常铺设有砂或碎石组成的土垫层。土垫层的作用是避免落石直接冲击棚洞,缓冲落石的冲击力。长期以来,关于土垫层厚度对缓冲效果影响的研究较少,因此,还未形成统一的理论用于指导土垫层厚度的设计。本项研究运用离散单元方法建立落石冲击土垫层的数值模型,探究垫层厚度和落石下落高度对土垫层缓冲落石冲击力特性的影响。研究结果表明:落石冲击力峰值与落石下落高度呈幂函数关系,顶板中心力峰值与下落高度呈线性正相关关系;随着垫层厚度的增加,落石冲击力峰值减小,当垫层厚度增加到落石直径的1.0倍之后,落石冲击力峰值与垫层厚度无关;随垫层厚度的增大,顶板中心力峰值与落石冲击力峰值的比值减小,垫层缓冲效果增大,当垫层厚度增加到落石直径1.5倍之后,垫层缓冲效果增加不明显;垫层厚度建议取值为落石直径的1.5倍。

       

      Abstract: Rock sheds is one of the main engineering solutions for mitigating rockfall disaster in the mountainous regions of western China. Typically, the roof of a rock shed is covered with a soil cushion composed of sand or gravel. The function of soil cushion is to avoid the direct impact of rockfall on the shed and absorb the impact force of the falling rocks. For a long time, there has been limited studies on the influence of soil cushion thickness on its buffering effect, leading to a lack of a unified theory guiding the design of soil cushion thickness. In this study, the discrete element method was employed to establish a numerical model of rockfall impacting onto soil cushion, and the influence of cushion thickness and rockfall falling height on the buffering characteristics of soil cushion for the rockfall impact force was investigated. The results show that there is a power function relationship between the peak of rockfall impact force and the rockfall falling height, along with a linear positive correlation between the peak of roof center force and the rockfall falling height. The peak of rockfall impact force decreases with increasing cushion thickness. Once the cushion thickness reaches 1.0 times of the diameter of rockfall, the peak of rockfall impact force becomes independent of cushion thicknessAs cushion thickness increases, the ratio of the peak bottom center force to the peak rockfall impact force decreases, indicating an enhancement in the soil cushion's buffering effect. However, when the cushion thickness reaches 1.5 times of the rockfall diameter, the enhancement in buffering effect becomes less significant. Therefore, the recommended cushion thickness is 1.5 times the rockfall diameter.

       

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