支护桩桩间土拱效应及合理桩间距分析

Analysis of soil arching effect of soldier pile and optimal pile spacing

支护桩合理桩间距的确定对桩基支护工程安全性和经济性具有重要意义。在合理拱轴线的假定下建立了土拱力学模型,分析了土拱拱脚处的受力特征,推导建立了拱脚在极限平衡状态下土拱极限跨度表达式,在考虑土拱侧向压力的条件下,分析了土拱拱高随土层深度的演化规律,研究结果表明:土拱跨度随土体力学参数的增大而增大,随桩后水平推力的增加迅速减小,同时桩后土拱极限拱高随着土层深度的增加而减小。通过工程实例对比验证了关系式的合理性,研究结果对支护桩设计有一定参考价值。

The rational pile spacing has significant influence on the safety and economy in the deep excavation supported by piles.A mechanical model of soil arching was created under the reasonable arching axis assumption,the mechanical characteristics of arch foot was analyzed,and the limit span of soil arch was calculated under ultimately balanced condition;the revolution of arch height with soil depth was analyzed in addition.The results shows that the limit arch span increases with the increase of soil strength,and decreases rapidly with the increase of horizontal force,while with the increase of depth,the limit arch height decreases.The rationality of the relation is verified by the comparison of projects,and the analysis results could be referred in the soldier pile design.