摘要
基于"上海市虹桥综合交通枢纽交通中心工程西交通广场"工程现场静载荷试验和桩身应力测试结果,分析竖向荷载作用下大直径超长钻孔灌注桩在成层土中的荷载传递特性。本工程试桩已加载至破坏,对此试验结果进行分析,能为深入研究大直径超长钻孔灌注桩的承载性状提供有价值的工程参考。本次试验结果表明:1)大直径超长钻孔灌注桩桩端承载力所占比例较低,荷载-沉降关系为陡降型,存在明显拐点;2)桩侧与桩端阻力非同步发挥且相互影响,而上下土层侧阻力系先后发挥至极限;3)根据试桩实测数据,土层埋深对桩周具有相似物理力学性质土层的侧摩阻力影响较大。
Based on the pile load test and stress test results of ＂The West Traffic Center Plaza of Shanghai Hongqiao integrated transport hub＂project, the load transfer characteristics of ultra-long large-diameter bored piles in layered soil under the vertical load was analyzed. The piles in this project were loaded to destruction, which provided a valuable reference for in-depth study of ultra-long large-diameter bored pile bearing capacity of the works. The results showed that：1）Ultra-long large-diameter bored pile tip bearing capacity had the lower proportion, and load-settlement type relationship was dropped. There is an obvious inflection point;2）pile shaft resistance and pile tip resistance played a non-synchronous interaction. Shaft resistance of soil from top to bottom was played one after another to the limits;3）In accordance with the measured data of test piles, the depth of the soil with similar physical and mechanical properties influenced the pile shaft resistance.
关键词
大直径超长钻孔灌注桩
静载荷试验
分层荷载传递
特性分析
ultra-long large-diameter bored pile
static load test
hierarchical load-transfer
characteristics analysis
