北京超长灌注桩单桩承载特性研究  

Behaviors of bearing capacity of ultra-long bored piles

作　　者：邹东峰[1] 

机构地区：[1]中冶建筑研究总院有限公司,北京100088

出　　处：《岩土工程学报》2013年第S1期388-392,共5页Chinese Journal of Geotechnical Engineering

摘　　要：对北京CCTV新台址、国贸三期A阶段2个典型试验桩工程进行对比分析,研究了超长灌注桩桩侧、桩端阻力的发挥特性。研究表明:荷载作用下超长桩的桩顶变形主要由桩身的压缩组成,桩端阻力对总承载力的贡献较小;黏土层的桩侧阻力发挥呈加工软化现象,砂性土桩侧阻力发挥呈加工强化现象,且桩侧阻力的发挥存在深度效应;按规范估算的超长灌注桩承载力分布与实际测试结果差异较大。提出采用有效的清渣工艺和后压浆工艺是超长灌注桩的必要措施。Based on the comparison and analysis of the static load tests on the experimental ultra-long bored piles of CCTV Tower and World Trade Center Tower(third stage) in Beijing,the behaviors of the pile tip resistance and the shaft resistance are studied.The results show that the deformation of pile top is mainly from its compression under loads.The tip resistance makes minor contribution to the bearing capacity relative to the shaft resistance.The pile shaft resistance exhibits a softening phenomenon in clay layer and a hardening phenomenon in sandy soil layer,and its play exhibits depth effect.The bearing capacity distribution of piles estimated according to the specifications is greatly different from the test results.Both the effective cleaning residue process and the post grouting means are proposed to be necessary measures for the ultra-long bored piles.

关 键 词：超长灌注桩 试验桩 桩端阻力 桩侧阻力 

分 类 号：TU473.1[建筑科学—结构工程]