高原山区碎块石土地基微型桩单桩下压荷载下的受力特征

采用双折线荷载传递函数,推导山区碎块石土地基微型桩在下压荷载作用下单桩受力的理论解,建立该类地基微型桩抗压承载力随桩长与桩径间的变化关系,评价不同下压荷载下桩端桩侧承担的荷载比例。结果表明:碎块石土地基中的微型桩,桩端承担的荷载比例随着下压荷载、桩径的增加而增大,随着桩长的增加而减小;下压荷载与桩顶位移的关系可分为两段,第一段增加的荷载主要由桩侧承担,第二段增加的荷载主要由桩端承担。碎块石土地基微型桩,桩侧和桩端同时发挥作用,设计时应同时考虑桩侧和桩端阻力的影响。

The stress characteristics of micro-piles under single pile pressure on gravelly soil foundation in the mountainous plateau area

Based on the bilinear line load transfer function,the theoretical solution of micro-pile bearing capacity under pressure force on gravelly soil foundation is deduced,the relationship between the compressive bearing capacity of the micro-pile and the length,diameter of the pile is established and the proportion of load for pile-side and pile-tip under different pressure force is evaluated.The results show that the proportion of load for pile-tip increases with the pressure force and the diameter,and decreases with the length.Moreover,the relationship between the pressure force and the displacement of pile-top can be divided into two stages,the increased load in the first stage is mainly borne by pile-side,and the increased load in the second stage is mainly borne by the pile-tip.Therefore,in the design of micro-pile on gravelly soil foundation,the influence of pile-side and pile-tip resistance should be carefully considered.