落石冲击作用下拦石桩设计方法研究OACSTPCD
Study on design method of rockfall retaining pile under rockfall impact
桩板拦石墙是一种拦截落石的新型被动防护结构,由悬臂桩、桩间板和缓冲垫层组成.这种结构具有地形适应性强、占地面积小、拦截高度大等优点,在落石高发区得到了应用.然而,由于悬臂桩的极限承载力缺乏详细的报道,因此无法为工程实践提供指导.文章首先根据落石冲击力传播特征,提出缓冲垫层的合理厚度;然后根据桩身的受力和变形特性,采用弹性固支悬臂梁模型和Winkler弹性地基梁模型推导了桩身内力、位移的理论计算方法,实现了落石冲击作用下悬臂桩设计参数的自动求解.结果表明:当落石直径为2m、冲击高度为7.0 m,冲击速度为10m/s,且砂土垫层厚度为落石直径的1.5倍时,双排三肢钢筋1.5 m×1.2m悬臂桩可承受冲击力为2.51×106N且冲击能量为565 kJ的落石冲击.对于冲击能量更高的情况,建议优先提高拦石桩的抗弯能力.研究可为西部山区岩崩防灾减灾提供科学依据.
Pile-slab rockfall retaining wall is a novel passive protective structure designed to intercept falling rocks.It is made up of cantilever piles,pile-intermediate slabs,and cushion layers.This structure features strong terrain adaptability,small footprint,and high interception height,making it applicable in high-risk rockfall areas.However,due to the lack of detailed reports on the ultimate bearing capacity of cantilever piles,guidance for engineering practice is unavailable.This paper first proposes a reasonable thickness for the cushion layer based on the characteristics of the propagation of falling rock impact forces.Then,according to the stress and deformation characteristics of the pile body,theoretical calculation methods of the internal forces and displacements of the pile body are derived using the elastic support cantilever beam model and the Winkler elastic foundation beam model,enabling the automatic determination of design parameters for cantilever pile under falling rock impact.The results indicate that for a rockfall with a diameter of 2 m,impact height of 7.0 m,impact velocity of 10 m/s,and a cushion layer thickness of 1.5 times the rockfall diameter,a double-row triple-limb steel-reinforced 1.5 m × 1.2 m cantilever pile can withstand an impact force of 2.51 × 106 N and impact energy of 565 kJ.For cases with higher falling rock impact energy,it is recommended to prioritize enhancing the bending resistance of the retaining wall.This research provides a scientific basis for disaster prevention and reduction in rockfall-prone areas in the western mountainous regions of China.
田玥琳;罗刚;邹鹏;张龙睿;侯易凡
西南交通大学地球科学与环境工程学院,四川成都 610031
地质学
落石缓冲垫层拦石桩桩身内力优化设计
rockfallcushionrockfall retaining pileinternal force of pileoptimal design
《中国地质灾害与防治学报》 2024 (003)
88-96 / 9
国家重点研发计划(2022YFC3005704);国家自然科学基金面上项目(42277143);四川省自然科学基金面上项目(2024NSFSC0100);四川省自然资源厅科研项目(KJ-2023-004)
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