摘要
为探讨填海地层挤扩支盘桩的承载机理,依托深圳市滨海大道下沉隧道桩基工程,开展了挤扩支盘桩抗压、抗拔现场静载试验,分析了挤扩支盘桩桩顶位移规律、桩身轴力分布规律、支盘结构承载情况及分担比例等。结果表明,支盘桩达到桩顶极限荷载量时,仍具有较大的承载潜力;支盘桩桩身轴力分布在支盘位置发生突变,且盘位置突变量值高于支位置;埋深较深处盘结构与埋深浅处盘结构相比,发挥承载能力时具有明显的滞后效应;抗压支盘桩桩顶受荷较大时,支盘结构发挥主要承载功能,桩端及桩侧发挥辅助承载功能;设计时应将支盘结构设置于力学性质较好的土层,以充分发挥桩身范围内各土层承载能力;支盘结构的施作对支盘周土体具有挤扩压硬作用,提高了支盘周土体的承载能力。
In order to explore the load-bearing mechanism of the extruded branch pile in the reclamation stratum, relying on the pile foundation project of the immersed tunnel of Binhai Avenue in Shenzhen, the static load tests on the compressive and uplift of the extruded branch pile are carried out, the displacement law of the pile top, the distribution law of the axial force of the pile body, the bearing capacity and the sharing ratio of the extruded branch pile, etc. are analyzed.. The results show that:(1) when the extruded branch pile reaches the ultimate load of the pile top, it still has a large load bearing potential;(2) the axial force distribution of the extruded branch pile is abrupt at the branch position, and the sudden change value of the plate position is higher than the branch position;(3) in terms of burial depth, the deeper plate structure has a significant hysteresis effect when it exerts the bearing capacity;(4) when the load on the pile top of the compression branch pile is large, the branch structure plays the main bearing function, and the pile end and pile side play the auxiliary bearing function;(5) the branch and plate structure should be set on a soil layer with good mechanical properties by design to give full play to the bearing capacity of each soil layer within the scope of the pile;and(6) the construction of the branch plate structure has the effect of squeezing and expanding the soil around the branch plate, and thus improves the bearing capacity of the soil around the branch plate.
作者
肖友银
喻伟
施劭矗
马龙祥
汪波
XIAO You-yin;YU Wei;SHI Shao-chu;MA Long-xiang;WANG Bo(China Railway Southern Investment Group Co.Ltd.,Shenzhen 518000,China;MOE Key Laboratory of Transportation Tunnel Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《公路》
北大核心
2023年第1期93-101,共9页
Highway
基金
国家自然科学基金项目,项目编号U2034205、51878571。
关键词
扩挤支盘桩
抗压承载力
抗拔承载力
现场试验
承载机理
extruded branch pile
compressive capacity
pull-out bearing capacity
field test
bearing mechanism
