横向流动土体作用下的群桩反应性状

借助FLAC3D程序,分析了基坑开挖后土体横向流动作用下坑内群桩的反应性状。研究了两桩、四桩、五桩、六桩群桩中基桩的反应性状,并与相同位置的单桩反应进行了比较,得到了受横向流动土体作用的群桩相互作用规律:桩基连线平行于边坡布置的两桩,相互影响并不明显;而在其它情况下,前排桩对后排桩遮拦、后排桩对前排桩阻挡,均使受影响的桩基内力分布改变,桩身最大变形量减小;受周围越多、越近桩基的影响,基桩的内力和变位减少得越多。根据桩间土体的成拱特征,定性解释了群桩相互作用的机理与规律,具体工程的现场量测结果也验证了此结论。

Behavior of pile groups subject to excavation-induced lateral soil movement

Three dimensional finite-difference program of FLAC3D was applied to study pile groups behaviors due to excavation-induced lateral soil movements,including two piles in a row parallel to excavation slope or in a line perpendicular to slope,four-pile,five-pile,3×2 and 2×3 pile groups.Comparing the response of a pile among pile groups with that of a single pile located in the same position on slope,the interaction effect in pile groups had been found.Namely,when piles were arranged in a row parallel to slope,the interaction effect between piles was insignificant,while in other arrangements,the existence of either a front pile(a row front piles) or a rear pile(a row rear piles) could all reduce the displacement and maximum bending moment of the adjacent pile,and when a pile was located in groups with small space or among a number of piles,the interaction effect would increasey significantly.These conclusions were explained by arching effects of soil between piles theoretically,and verified by a practical project.